Aripar4_RefMan

1

1. INTRODUCTION .........................................................................................................................3

2. THE ARIPAR-GIS USER INTERFACE ....................................................................................4

2.1 TABLE OF CONTENT (TOC) .............................................................................................................5 2.2 MENU BAR........................................................................................................................................5 2.3 BUTTON BAR ....................................................................................................................................9 2.4 TOOL BAR ......................................................................................................................................10

3. FREQUENTLY USED ARCVIEW PROCEDURES ..............................................................13

3.1 WORKING WITH THEME LAYERS ....................................................................................................13 3.2 LEGEND EDITOR.............................................................................................................................13 3.3 DISPLAY LABELS.............................................................................................................................13 3.4 REMOVE LABELS ............................................................................................................................14 3.5 PRINTING A MAP .............................................................................................................................14

4. ARIPAR-GIS PROCEDURES .................................................................................................15

4.1 SETTING THE RASTER MAPS SCALE ...............................................................................................15 4.2 SET THE TRANSPARENT COLOUR TO THE RASTER MAP OF THE IMPACT AREA..............................18 4.3 DRAW THEMES ...............................................................................................................................19 4.4 POPULATION DISTRIBUTION ...........................................................................................................20 4.5 POPULATION CONCENTRATED INTO VULNERABILITY CENTRES ...................................................22 4.6 DRAW PLANTS (DOCKS).................................................................................................................22 4.7 DRAW ROADS (RAILWAYS, PIPELINES, COURSES) .........................................................................23 4.8 DRAW POINT RISK SOURCES ........................................................................................................23 4.9 DRAW LINEAR RISK SOURCES ......................................................................................................24 4.10 USER DEFINED THEMES ...............................................................................................................25 4.11 ASSOCIATION OF DOCUMENTS TO THEMES .................................................................................26 4.12 OPEN DOCUMENTS ASSOCIATED TO GRAPHICAL OBJECTS .........................................................27 4.13 ASSOCIATE VIEWS TO GRAPHICAL OBJECTS ...............................................................................28

5. THE ARIPAR DATABASE .......................................................................................................30

5.1 METEO AGGREGATION DIALOG .....................................................................................................31 5.2 TIME PERIODS DIALOG ..................................................................................................................31 5.3 DISTRIBUTION OF METEOROLOGICAL DATA...................................................................................32 5.4 GRAPHICAL REPRESENTATION OF THE METEOROLOGICAL DATA .................................................33 5.5 POPULATION CATEGORIES DIALOG...............................................................................................34 5.6 POPULATION CATEGORIES PRESENCE DIALOG ............................................................................34 5.7 DESCRIPTION OF THE SPATIAL DISTRIBUTION OF THE POPULATION..............................................35 5.8 VULNERABILITY DATA DIALOG ........................................................................................................36 5.9 PARAMETERS FOR ROAD TRANSPORT ..........................................................................................40 5.10 OUTCOME TYPE ...........................................................................................................................41 5.11 ACCIDENT DEFINITION..................................................................................................................42 5.12 F-N PARAMETERS DIALOG ..........................................................................................................42 5.13 RISK SOURCES DEFINITION DIALOG ...........................................................................................43 5.14 OUTCOMES DEFINITION DIALOG .................................................................................................46

5.14.1 New Outcome.....................................................................................................................46 5.14.2 Existing Outcome...............................................................................................................47

5.15 RISK SOURCES DEFINITION DIALOG FOR ROAD TRANSPORT ....................................................49 5.16 GENERATION OF THE ROAD TRAFFIC TOP EVENTS....................................................................49 5.17 VULNERABLE CENTRES DIALOG..................................................................................................50 5.18 POPULATION AREAS DIALOG.......................................................................................................51 5.19 SOURCE AGGREGATION DIALOG.................................................................................................51

6. RISK CALCULATION ...............................................................................................................53

6.1 FITTING PROGRAM .........................................................................................................................53 6.2 FITTING PROGRAM GIS DIALOG.....................................................................................................56

2

6.3 SELECTION OF SOURCES...............................................................................................................57 6.4 CHECK PROCEDURE.......................................................................................................................58 6.5 RISK SOURCE CALCULATION .........................................................................................................58 6.6 DISPLAY OF RESULTS ....................................................................................................................59

7. REPORT WRITER MODULE ..................................................................................................60

8. PROJECTS MANAGEMENT ...................................................................................................62

8.1 TOOLBAR........................................................................................................................................62 8.2 DIALOG BUTTONS ...........................................................................................................................63 8.3 MENU PROJECTS MANAGEMENT...................................................................................................63 8.4 MENU CONFIGURATION .................................................................................................................65 8.5 MENU COLOUR SELECTION ...........................................................................................................65

APPENDIXES ........................................................................................................................................67

A.1 BASIC EQUATIONS OF THE ARIPAR METHODOLOGY ..................................................................67 A.2 INTERPOLATING FUNCTIONS ....................................................................................................71

A.2.1 Consequence Computation Functions........................................................................71 A.2.1.1 Unconfined Explosion (P = overpressure):..................................................71 A.2.1.2 Physical Explosion (P = overpressure): ........................................................71 A.2.1.3 Fireball (I = thermal radiation) .........................................................................72 A.2.1.4 Jet fire (I = thermal radiation): ........................................................................72 A.2.1.5 Poolfire (I = thermal radiation): .......................................................................72 A.2.1.6 Gas Jet Dispersion (C = concentration)........................................................72 A.2.1.7 Heavy Gas Dispersion for Continuous Release from Pool (C = concentration) ..........................................................................................................................73 A.2.1.8 Heavy Gas Dispersion for Catastrophic Release (C = Concentration) ..73 A.2.1.9 Neutral Dispersion (Gaussian) ........................................................................74

A.3 INPUT FILES FOR THE COMPUTATION OF THE ADAPTIVE COEFFICIENTS ................................75 A.3.1 Unconfined Explosion....................................................................................................75 A.3.2 Physical Explosion ...........................................................................................................76 A.3.3 Fireball .............................................................................................................................76 A.3.4 Jet fire ..............................................................................................................................76 A.3.5 Poolfire.............................................................................................................................77 A.3.6 Gas Jet Dispersion ........................................................................................................77 A.3.7 Heavy Gas Dispersion with Pool Formation and Evaporation ................................78 A.3.8 Heavy Gas Dispersion – Catastrophic Release ........................................................78 A.3.9 Neutral Dispersion (Gaussian) .....................................................................................79

3

1. INTRODUCTION

This Reference manual complements the User’s Guide and describes all commands, dialogs, risk analysis equations, input data format and reporting available in ARIPAR 4.0. This report will be periodically updated to document the software improvements concerning e.g. the interface with commercial software packages for consequence calculation, a database on accident frequencies, the optimisation of algorithms for the contour and grid representation of the local and individual risks. Moreover, in the near future ARIPAR 4.0 will have a new add-on module for Domino effects analysis, which is currently under testing at the Chemical, Minerary and Environmental Technologies Engineering Department (DICMA) of the University of Bologna. The document is organised as follows: − Section 2 contains a description of the ARIPAR-GIS user interface, including a

quick reference of menu, button and tool bars of ArcView; − Section 3 describes all ArcView procedures that are used for risk analysis; − Section 4 contains the detailed description of the ARIPAR 4.0 procedures for the

characterisation of both the impact area and source area as far as the geographically referenced data are concerned;

− Section 5 describes the database from the user point of view; − Section 6 contains the description of command for using the risk calculation

modules; − Section 7 is devoted to the use of module that supports the preparation of the

documentation on risk analysis; − Section 8 describes the project management. Three appendixes are also included, containing: − Appendix 1: Basic Equations of the ARIPAR Methodology − Appendix 2: Interpolating Functions − Appendix 3: Input Files for the Computation of the Adaptive Coefficients For the installation of ARIPAR-GIS see Section 4 of the Getting Started Manual.

4

2. THE ARIPAR-GIS USER INTERFACE

The ARIPAR-GIS user interface contains the following main elements: • Table of Contents (TOC); • Menu bar; • Tool bar; • Button bar; • The View.

The ARIPAR-GIS user interface The description that follows assumes that the reader is familiar with the basic terminology and command of ArcView 3.2. Therefore, the description of ArcView commands is not given in this report, except for a quick reference, and for some frequently used commands. Some other ArcView commands are described only when they are part of ARIPAR-GIS procedures. Before starting working with ARIPAR, readers not familiar with Arcview are invited to practice the frequently used commands by referring to the Arcview user manual, to the on-line Help utility, or to some of the Tutorial guides available on Internet, as for instance: • http://www.eslarp.uiuc.edu/gis/arcview/index.htm • http://www.keele.ac.uk/depts/cc/helpdesk/arcview/av _prfc.htm • http://www.library.wisc.edu/libraries/Steenbock/bip age/arcview/arcview.htm

TOC, Table

of Content

Menu Bar

Map scale

Button Bar

Tool Bar

Main View

Standards

ARCVIEW

Buttons

ARIPAR

Buttons

5

− http://webgis.wr.usgs.gov/arcview.htm

2.1 Table of Content (TOC)

The Table of Content (TOC) lists the themes (layers) in the View with their legend, as shown below:

The Table of Content of ARIPAR-GIS The TOC shows the thematic layers used in ARIPAR-GIS. Layers have a name and a legend definable (symbols, colours, labels) by the analyst, Any thematic layers can be displayed or not by turning on/off the check box next to the theme’s name. The theme at the top of the TOC is drawn on top of those below it. The order themes are drawn can be changed by dragging themes up and down in the TOC.

2.2 Menu Bar

The menu bar is organised as follows: This is the standard ArcView menu bar, with the addition of Tools, Table, Risk menu, and the items Load Colour Map, Save Colour Map of the Theme menu, and Reset Project in File Menu, which are specific of ARIPAR-GIS. Since the meaning of items in Arcview menus can be found through the Help function, they will only be listed in the tables that follow. Among all available commands, those

6

of interest for the ARIPAR application are highlighted in bold blue. Therefore, an analyst not familiar with ArcView should address his/her attention to these commands. Some menu items a have a corresponding button in the Button bar: these commands are marked with the symbol The following are the ArcView menus. File menu Nr. Name item Action 1 Save View Save the current working project and View

setting 2 Extensions Open the dialog extension manager 3 Print Print the current window 4 Print Setup Setup printer 5 Export Export current View to a standard export file

format 6 Manage data sources Mini File system manager: create folder,

remove and copy data from inside ArcView 7 Exit End the ARIPAR-GIS session

Edit menu Nr. Name item Action

1 Delete Themes Delete selected themes from current view 2 Cut Graphics Cut selected graphics from current view 3 Copy Graphics Copy selected graphics from current view 4 Delete Graphics Delete selected graphics from current view 5 Paste Paste object from clipboard 6 Select All Graphics Select all graphics from current window

View menu Nr. Name item Action 1 Properties Open the properties dialog of the current

view 2 Add Themes… Add one or more themes to the current view 3 New Theme Create a new theme in the current view 4 Theme on Activate all themes 5 Theme off De-activate all themes 6 Layout Open the View Layout manager 7 TOC Stile Define the font, style, and color of the TOC.

8 Hide/Show TOC Hide or Show the TOC from the current view

9 Full Extent Zoom the current view to full extent 10 Zoom in Increases the scale view 11 Zoom out Decreases the scale view 12 Zoom to Theme Zoom view to the extent of the selected

theme 13 Zoom to Select Zoom view to the extent of the selected

items in the View 14 Zoom Previous Undo zoom 15 Find Find string in the attribute table of the

selected theme

7

Theme menu Nr. Name item Action 1 Properties Open the properties dialog of the current

theme 2 Start Edit Start editing the current theme (attribute

table and graphical objects) 3 Save Edit Save editing of the current theme 4 Save Edit as… As above but specifying a new name 5 Convert to Shapefile Export current theme to Shapefile format 6 Export to Table Export only attribute table 7 Edit Legend Open the legend dialog editor 8 Hide/Show Legend Hide/Show the legend of the current theme 9 Load Colour Map Load a colour map for the selected 1-band

raster image (ARIPAR command) 10 Save Colour Map Save the colour map of the selected 1-band

raster image (ARIPAR command) 11 Auto Label Insert labels in the current view from the

selected theme and field name 12 Remove Label Remove labels from the current view 13 Table Open the attribute table of the current

theme 14 Query Open the dialog for querying the current

theme 15 Clear Selected Features Clear the selection of all features

Graphics menu Nr. Name item Action 1 Properties Edit graphics properties 2 Text and Label Default Define graphic text and label default setting 3 Size and Position Define size and position 4 Align Define text alignment 5 Bring to Front Bring graphic to front 6 Send to Back Send graphic to back 7 Group Group selected graphics 8 Ungroup Ungroup selected graphics 10 Attach Graphics Attach selected graphics to the current

theme 11 Detach Graphics Detach graphics from the current theme

Windows menu Nr. Name item Action 1 Tile Tile all open windows 2 Cascade Cascade all open windows 3 Arrange Icons Align minimised windows 4 Show Symbol Windows Open the symbol properties dialog 5 Show Control Tools Open the control tools panel of the dialog

editor extension 6 Project List List of all open windows

Help menu Nr. Name item Action 1 Help Topics Open ArcView help topics windows 2 How to Get Help Open ArcView help on help window

8

3 About ArcView Info on ArcView 4 Aripar-Gis Info Info on ARIPAR-GIS

The following are ARIPAR menu. The actions of the different items are described in this report. Those having a button are indicated with the symbol. Tools menu Nr. Name item Action 1 Scale Image Set a scale to the raster map representing

the impact area 2 Edit World File Open the World file to modify some

parameters – not to be used 3 Documents Management Opens the Documents form with the list of

documents associated to the theme or object selected.

4 … Setup Applications Load the application tools to open documents

5 Themes Management Open the dialog that is used to associate to a given feature of the selected layer a View

6 Report Tables menu Nr. Name item Action 1 Open Theme Table Open the attribute dialog of the selected

theme starting from the first record 2 New Record… Insert a new feature in the current theme 3 Edit Record… Open the attribute dialog of the selected

theme and show the selected record 4 Delete Record… Remove the selected record 5 Time Period 6 Meteo Aggregation 7 Meteo 8 Population Categories 9 Popilation Presence 10 Land Use 11 Dispersion Probit 12 Explosion Probit 13 Fire Probit 14 Road Type 15 Outcome Type 16 Initiating Events 17 F-N Parameters 18 Multiple FIT File Setting

Risk menu Nr. Name item Action 1 Sources Risk Calculation Selection of the sources to be taken into

account in the risk calculation 2 Point Local Risk

Contributors Determine and show in a diagram the major contributors to the risk in a selected point

9

3 Local risk – Point Representation Determine and show the local risk in all points of the calculation grid.

4 Local risk – Grid Representation Determine and show the local risk represented in a grid with user defined (square) cell dimension. IDW interpolation method applied.

5 Local risk – Contours Determine and show the local risk contours. IDW interpolation method applied.

6 Individual risk – Point Representation

Determine and show the Individual risk in all points of the calculation grid.

7 Individual risk – Grid Representation

Determine and show the Individual risk represented in a grid with user defined (square) cell dimension. IDW interpolation method applied.

8 Individual risk – Contours Determine and show the Individual risk contours. IDW interpolation method applied

9 F-N Cumulative Curves Show F-N curves of the societal risk by typology of sources

10 I-N Histogram Show the I-N histogram of the societal risk

11 Risk Source Importance Show the histogram containing, for each source type, the annual frequency of fatality vs. the number of fatalities

12 Risk Source Importance (N) Show the histogram of the major contributors to the area risk for a given number of fatalities

13 Accident Damage Curves Open the Accident dialog for the selection and representation of damage curves

14 Remove Risk Themes Remove all risk themes from the view

2.3 Button Bar

When clicking on a button of the Button bar an action immediately takes place. Generally this action is preceded by the selection of a theme. The button bar of ARIPAR-GIS contains, besides the standards Arcview buttons, the following commands: ARIPAR-GIS Button bar Nr. Action 1 Hide/Show the TOC 2 Compress the legend of the selected theme 3 Symbol dialog 4 Attach Labels 5 Remove Labels 6 Documents Management 7 Themes Management

1 2 3 4 5 6 7 8 9 10

10

8 Open the database of attributes associated to the selected theme. 9 Set the info field among those contained in the previously open database.

The content of this field will be displayed in the status bar of the main window each time a feature is selected.

10 Layout For the sake of completeness, the commands of ArcView‘s Button bar are summarized in the following tables. Those commands that are useful for the ARIPAR-GIS application are highlighted. ArcView Button bar

Button Description

Save view project

Add theme

Theme properties

Legend editor

Open attribute table

Find

Query theme

Zoom to full extent

Zoom to active theme(s)

Zoom to selected features

Zoom in / Zoom out

Zoom to previous extent

Clear selected features

Help

2.4 Tool Bar

Differently from Button bar, a command of the Tool bar has effect only after selecting an object of the theme. Therefore, a tool bar is always preceded by the selection of a theme from the TOC and followed by the selection of the object in the view. Besides the Arcview standard tool buttons, the following have been added:

1 2 3 5 6 7 8 9

4 1,2,3,4,5

11

ARIPAR-GIS Tool bar Nr. Name item Action 1 Documents

Open the Document management module with the list of documents associated to the selected object 2 open the Post-It notes associated to the selected object

2 Add theme

Add a theme to the View associated to an object of a theme in the Aripar-gis View

3 Magic Wand Generate Source from the selected feature 4 Draw objects

Draw a new object of the active theme; the object can be a polygon (1,2,3) a line (4) or a point (5).

5 Delete objects

Delete the selected object and all associated attributes

6 Display data Open the attribute database associated to the selected object

7 Info feature Display in the Status bar the content of the field previously selected using the button 4 of the Button bar

8 Draw Damage Curves Open the Accident dialog for the selection and the representation of damage curves

9 Local Point Risk Contributors

Show in a diagram the sources contributors to risk in a selected point

For the sake of completeness, the commands of ArcView‘s Tool bar are summarized in the following tables. Those commands that are useful for the ARIPAR-GIS application are highlighted. ArcView Tool bar

Button Description

Identify

Pointer

Vertex edit

Select feature

Zoom in / Zoom out to selected rectangle

Pan

Measure distance

Insert label

Insert text. Open the list of tool buttons to insert text on themes

Insert graphic. Open the list of tool buttons to draw polygons, lines and points.

12

The set of commands that appear in ARIPAR-GIS dialogs is listed below. They are summarised here to avoid repeating their description with all dialogs. Other more specific buttons are described together with the dialog they belong to. ARIPAR buttons in dialogs Command

Button Description

First record View the record of the selected database Last record View the last record Previous rec. View the previous record Next record View the next record Remove Remove the selected record from the database Add Add a new record to the database Confirm

Confirm the editing of the selected record (save data)

Remove

Remove the selected field from table

Add

Add a new field to the table

Edit

Edit the field of the table

Show

Highlight the object associated with the selected record

Zoom Zoom in to the graphical object Find .?. Find an element from the associated menu

Browse .Browse…. Open the browser to select a file

Select from list .<List Name>.

Open a menu for selecting an element

Toggle data … Maximise/Minimise the dialog

Set point Define point

Open document

Shows the two button to open respectively the Document management dialog and the Post-it dialog

Open theme Allows to link a view (containing any number of themes) to any objects of any vector theme

Commands common to ARIPAR-GIS dialog boxes

13

3. FREQUENTLY USED ARCVIEW PROCEDURES

In this chapter some Arcview procedures that are frequently used in ARIPAR-GIS are described. For more information refer to the Arcview documentation.

3.1 Working with Theme layers

Dragging the border on the left/right direction can modify the width of the TOC. Alternatively:

• Click the button to shrink the TOC so that the View reaches the max dimension. Click it again to restore its standard width.

• A layer must be selected before making any operation on it. • Click on the layer to make it active.

3.2 Legend Editor

The analyst, by means of the Legend Editor, can modify the legend of a theme This is an Arcview feature, very important in ARIPAR-GIS, whose description can be found in the Help function or in the ArcView documentation. What follows are only the main commands to modify the legend of a theme. It is possible to change the standard legend (colours) and symbols of the legend of any theme by clicking twice on the layer in the TOC. The legend editor is displayed from which symbols, colours, type of lines, surface, points can be modified.

3.3 Display labels

It is frequently useful to display labels to describe the objects of the selected theme, e.g. the name of cities next to each city in the theme of cities. • Select a layer, e.g. population • Select the Auto Label item from the Theme menu • In the dialog that appears set the Label Field you want to display, e.g. Categoria

14

• Click OK: the labels are displayed at the correct location Refer to the Arcview documentation or the Help menu for details.

3.4 Remove labels

To remove from the screen the labels previously displayed: • Select the layer • Select the Remove Label item from the Theme menu

3.5 Printing a map

All themes that are displayed on the screen can be printed using the Layout functionality of ArcView. To have advanced commands available, load the Legend Tool from the list of Extensions. From the View menu select the Layout item; To get the layout it is sufficient to select the template of the page. The generated layout contains the active themes and all related layers, the wind rose, the scale of the map, and the title. Each element in the layout can be modified (just click twice on it), as for instance add notes, modify fonts, add symbols, etc. An element can be deleted just selecting it and pressing the Cancel key of the keyboard.

15

4. ARIPAR-GIS PROCEDURES

4.1 Setting the raster maps scale

An important requirement of ARIPAR analysts is to work with geo-referenced vector and raster files. More specifically, on the impact map it is important to be able to perform distance measurements and to calculate areas. To this purpose ARIPAR-GIS offers the analyst different procedures, of growing complexity, which differ one another from the different type of data used. The only requirement is that the scanned map must have the North oriented towards the top of the screen. Windows tools e.g. Photoshop may be used for this purpose. Moreover, map scaling methods do not take into accounts the deformation of the map introduced by the scanner; to reduce it a practical rule is to have the site at the centre of the map where the deformation is lower. The selection of the Scale Image item of the Tools menu leads to the display of the following wizard:

This wizard contains three different procedures: • Select a procedure • Click .Continue >>. to proceed. The result of these procedures is the generation of the so-called World File. The world file is an ASCII file containing the dimensions of a pixel in map units in the x and y directions and the x and y co-ordinates of the top-left point of the map. The world file has the same name of the raster file with a “w” added to its extension. For instance, the world file of IspraSite.tiff is IspraSite.tiffw. For MS-DOS 8.3 naming conventions, the extension is given by the first and third characters of the raster file extension, plus a final “w”. Thus, the file Apex.tif has the world file Apex.tfw; the file Varese.bmp has the world file Varese.bpw, and so on. See Arcview the Help for further details. Two Ground Control Points + Reference source This procedure is applicable when the analyst has a geo-referenced satellite image or map as a reference source, from which to take the co-ordinates of two Ground Control Points (GCP) to determine the scale of the site image of interest. A GCP is a point on the earth for which the co-ordinates (according to the national or UTM co-ordinate system) are known. The following wizard is displayed, together with two views:

16

View 1: Geo-referenced image, and View 2: Image to scale Perform the four steps described in the dialog box. Load the reference image (step 1) and the site layout image (step 2) using the browse. • Select one point on the image and the corresponding point on the site map.

Repeat the same operation for the second point. • Finally click the .Scale. button. The World file is generated and stored in the same directory of the site map. ArcView does not rotate images; therefore, the above procedure is sufficiently accurate as a geo-reference tool when the site layout image has a very small amount of rotation (this is the reason why the North has to be oriented to the top of the screen) Two Ground Control Points This method is useful when the co-ordinates of two points taken e.g. from a reference map or from a GPS, are available. This module is similar to the previous one and gives the same result. Only one view is used.

17

One Ground Control Point + distance A single GCP and the real distance between two points probably represent the most frequent case, i.e. only the co-ordinates of the location is known. The scaling may be performed even if only the distance between two points is known. In this case the (fictitious) GCP is considered with co-ordinates (0,0) corresponding to the bottom-left corner of the map. The dialog is as follows.

To draw the line between two points: • Click the button • Click on the first point with the left button and then drag the mouse up to the

second point; when the mouse button is released, the number of pixels is shown on the right.

• Enter the real distance in meters in the Line Length field. If the co-ordinates of a point are known continue, otherwise click the Scale button • Click the button • Click with the mouse in a point of the map: the pixel co-ordinates are loaded; • Enter the real co-ordinates • Click the Scale button. • The following figure is an example of the result of this operation where the unique point with geographical co-ordinates has been chosen on the top-left corner of the map.

18

4.2 Set the transparent colour to the raster map of the impact area

When drawing themes using the raster map as background, it is more convenient to have in the TOC the (layer) map above the theme layer to be edited. To make the map transparent: • Make the (layer) map active in the TOC • From the Theme menu select the Load ColorMap… item; the browser is displayed; • Access the Colormap subdirectory (C:\Aripar.40\Colormap directory)

X = 569318

Y = 5051101

Click here and then

on the map to move

the point

Click here to assign

the scale to the map

Real length in

meters

Number of pixel

length

1000 m

19

The following colours are available: Black, cyan, green, magenta, red, and yellow. This is the colour that substitutes the black in the map, whereas the white is made transparent. Generally, black is used. In the directory there are also the same colours indicated with _clr. These files use the reverse mapping colour. • Select the colour and click OK. • Move (drag) the maps layer on the top of the TOC. This feature is also very useful to display the local/individual risk using the grid representation, since the transparent map over the coloured areas allows showing the locations subject the different risk values.

4.3 Draw themes

The scaled and transparent area raster map is used to draw all themes of interest, i.e. roads, railways, pipelines, etc. Drawing a theme means drawing all objects belonging to it. Objects of the same type, e.g. polygons, lines or points, make up a theme. To draw a polygon (e.g. plant, population): • Make the theme active

• Click the button • With the left button of the mouse click on the first point of the polygon; then move

to the second point and click there; move again on the next point and click, and so on. To stop, double click the left button. It is not necessary that the last point coincides with the first one.

Use this button to draw a rectangle and for a circle To draw a point (e.g. nodes, risk source in fixed installations, vulnerability centre): • Make the theme active

• Click the button • With the left button of the mouse simply click on the correct location. To draw a line (e.g. road, pipeline, railways, courses): • Make the theme active

• Click the button • With the left button of the mouse click on the first point of the polyline (node); then

move to the second point and click there; move again on the next point and click, and so on. To stop, double click the left button on a node.

Note: to draw a road, pipeline, railway and a course you need first to insert in the view the nodes that specify the start and the end of it; To delete any object (polygon, line, point): • Make the theme active

• Click the button Simply click on the object to remove Note: removing an object means removing all attributes associated to it. It may happen that the theme drawn needs some adjustments. For instance, a polygon representing a plant may not be correctly drawn. If the polygon has no

20

attributes associated, then it may be deleted and redrawn. However, when attributes have already been loaded, it is better to use the editing procedure of Arcview, which is briefly summarised below. To edit a graphical object • Make the theme (to be edited) active • Select Start Editing from the Theme menu • Click the vertex edit tool button • Click on the object to be edited: a set of points appears on the vertices of the

polygon • Click with the left mouse button on a point and drag it to the new position • To terminate, select Stop editing from the Theme menu and answer Yes to the

dialog box that appears. These commands are used to generate all themes. For each theme the procedure is always the same, i.e.: • Select the theme • Draw all graphical objects • Associate data to each object The description of the population is a good example for showing how themes are generated.

4.4 Population distribution

To draw the polygon for a given land use: • Make the Population theme active in the TOC;

• Click the tool button; • Draw the polygon. To draw the polygon click with the left mouse button on the first point, then go to the second point and click again, do the same for the third point and for all others up to the last point. Double click to complete the drawing. The last point should not coincide with the first point. The following figure shows the polygon generated using the transparent map as background for a residential area. Since such map is on the top of the TOC it can be seen very clearly. The resulting polygon has the colour assigned to the “No data” element of the Legend.

21

Attributes associated to the drawn polygon can be entered as follows: • Be sure that the Population theme is active in the TOC;

• Click the tool button; • Click on the polygon; • The Population Dialog associated to the theme is displayed;

• Enter attributes and click to confirm; After confirmation, the polygon coloured according to the colour assigned in the legend to the selected land use. The Population dialog used to enter data for the population distribution is shown below. It allows the analyst to enter the name of the area, the type (from menu) the number of people (density) from which the density (number of people) is determined. The distribution of the population is entered with the percentage for each category. Each polygon is then covered with a grid of points to be later used for risk calculation. To display the grid the Point theme must be active: a set of crosses appears (the cross symbol can be changed by the analyst using the Legend Editor). Each cell of the grid is associated the number of people and their probability of presence.

22

4.5 Population Concentrated into Vulnerability Cent res

These are points in the impact area where there is a concentration of people during a certain period of time, e.g. hospitals, churches, schools, railways stations, stadium, etc. To enter these point: • Select the Point theme

• Click the button • With the left button of the mouse simply click on the correct location: the symbol

appears. As any symbol in the TOC, it can be modified using the Legend Editor. To add the population distribution:

• Click the tool button; • Click on the point ; • The attribute dialog box associated to the theme is displayed;

• Enter attributes and click to confirm;

4.6 Draw plants (Docks)

This procedure is common to Plants and Population Areas. To draw plants: • Make the Plants theme active;

• Select the button (polygon drawing) • Draw the plants’ boundary; The polygon is coloured with the colour representing the “No data” in the Legend. For each plant add the attributes as follows:

23

• Click the tool button; • Click on the polygon;

• Fill in the fields of the associated dialog box and click to confirm

4.7 Draw roads (railways, pipelines, courses)

This procedure is common to roads, railways, pipelines and courses (ships). To draw a road, pipeline, railway or a course you need first to insert in the view the nodes that specify the start and the end of it; As before, the steps to draw the roads (railways, pipelines, and courses) theme are: • Make the Roads (railways, pipelines, courses) theme active;

• Select the button (line drawing) • Draw the roads (railways, pipelines, courses) of interest (only those on which

dangerous substances are transported; For each road (railway, pipeline, courses) add the attributes as follows:

• Click the tool button; • Click on the road (railway, pipeline, courses) line;

• Fill in the fields of the associated dialog box and click to confirm The following are the dialogs for describing road transport routes.

4.8 Draw Point Risk Sources

Risk sources in fixed installations are represented on the area map as points. The procedure for risk source description is as follows. • Make the Sources theme active;

• Select the button (point sources); • Draw the sources of interest; For each source add the attributes as follows:

• Click the tool button;

24

• Click on the source point or segment;

• Fill in the fields of the associated dialog box and click to confirm The following is the dialog box for describing the risk sources in fixed installations.

4.9 Draw Linear Risk Sources

Risk sources related to the transport of dangerous materials are represented on the area map as segments drawn on the transport path. These sources may be on roads, railways, and pipelines, and courses (ships). The common procedure for risk source description is as follows. • Make the Sources theme active;

• Select the button for line sources • Chose a path (road, railway, pipeline or course) and click where you wish that the

source start the then click on the endon the firstDraw the sources of interest; Or, if you know that the start and the end of the source coincide with nodes:

• Select the button for line sources • Click on the path, so that the source will be automatically generated. For each source add the attributes as follows:

• Click the tool button; • Click on the source point or segment;

• Fill in the fields of the associated dialog box and click to confirm

25

4.10 User defined themes

These theme does not intervene in the risk calculation. It can be used only for making the map clearer, i.e. it can be used to highlight the boundaries of the different industrial areas since dangerous plants may be both concentrated in a small area, and distributed over the whole impact area. Create a new theme by selecting in the “View” menu the “New Theme…” item, then specify the type and the filename of the theme, save it in the DB folder of your current project.

To create a feature use the tool button and to edit attribute click on the tool. The attribute table associated to this theme is very simple: only the name of the ID is considered by default. The analyst can edit the table by adding/removing fields. To modify some properties of fields:

• click the button: the list of fields appears: • Select the field to consider and click OK. It is also possible to: • Modify the field name • Modify the field width

26

• Make the field visible (true) / not visible (false). To change it enter t or f. • Make the field read-only or editable • ID field cannot be deleted, but simply hidden. To make this type of fields not

visible set Visible = f To add a new field:

• Click the button. • Select the type, enter the field name and the field width in the dialog boxes that

are displayed. The new field is added to the table. To delete a field:

• Click the button.

4.11 Association of documents to themes

Attributes describing some features of a theme are stored into the Attribute Table. ARIPAR-GIS offers the analyst the possibility to enhance the information related to a graphical object by associating it with a set of documents. These may be, for instance, drawings, photos, text documents, satellite images, and video clips. The possibility to deal with such a large variety of documents calls for the use of a Document Management System (DMS) embedded in the GIS. In fact the integration of a DMS with a GIS makes the data storage and retrieval particularly simple and flexible. For example, it would be easy to select a graphical object in a theme and then to find all documents related to it, or to select all documents that are associated to objects resulting from a spatial query, e.g. located within a specified distance. The relationship between features and documents is many to many, i.e. an object has many associated documents, and many objects can share the same document. Within ARIPAR a simple Document Management module has been developed to link graphical objects to any type of document, as represented in the following figure. Documents can be classified according to some user-defined criteria and stored into user-defined folders. The procedure to manage documents associated to graphical objects is as follows: • Select the theme of interest;

Layer 1

Layer 4

Layer 3

Layer 2

Object-Document link

Document-Object link

27

• Click the tool button to open the Document Management Module; • Click on the graphical object of interest; The Documents dialog appears on the screen:

Documents can be categorised according to some user defined classification criteria (Type), as for instance technical, legislation, and so on. The Documents form contains the name of the View, the name of the selected theme and the object name. All documents will be automatically copied in the DOC folder of the current project. To better characterise the linked document, the analyst can fill in other fields, i.e. the user–defined-group (Type), the name (Doc. Name), a short description, the source of the document, and the loading date. • Click to add a new document to those associated to the selected graphical

object and use the browser to find the document location (generally the Application is automatically recognised and set; if not it can be selected);

• Click to update the database. • Documents can be categorised according to some user-defined classification

(Type);

• The associated documents can be open by clicking the button. • The is used to unlink documents. • For a given document, the shows the associated graphical object, i.e. the one

described in the object field.

4.12 Open documents associated to graphical objects

To open a document: • Select the type of document by clicking .Select Type. and choose it from the list; • Search the document of interest

• Click on the icon in the dialog box: the document is open using the previously loaded application.

28

The button (type) lists all documents associated with the object of the type specified in the Type field.

The button (application) lists all documents that can be open by means of the selected application tool. Therefore it is possible to select documents of a given type and of a given format, e.g. all documents of *.pdf format.

Click the button to perform a new selection of documents. A document selected from the list has an associated object; the button icon allows highlighting the corresponding object on the map.

4.13 Associate Views to graphical objects

ARIPAR-GIS offers to the analyst a very powerful functionality represented by the possibility to link any graphical object in any theme with a View. In this View themes can be loaded, edited, etc. The following figure shows the Aripar-gis View in which another view has been linked to a plant. In the linked View other themes can be added, new themes can be generated, and so on using the ArcView commands. In this View the Aripar specific commands are not applicable. Vector files, such as CAD drawings, represent an important type of document that may be associated to graphical objects. The possibility to link a View avoids the need of purchasing a viewer for importing and displaying CAD files. Several views can be linked to the same object: The association of Views to an object follows a procedure similar to those previously described for documents and notes. To link a View to an object: • Select the theme in the Aripar-gis View

• Clicking on and then on an object. The Themes dialog box is displayed.

Aripar-gis View

Linked View

29

The theme source, must be copied manually, by the user, in the DB folder of the current project. It is necessary to tell ARIPAR-GIS on which view the theme must be loaded. It may be loaded either into an existing view (in this case select it from the menu which is displayed clicking the .View Name. button) or in a new view. In the latter case: • Enter the name of the view in the View-Name field; • Enter the name of the file to be written in the TOC in the Theme-Name field. All other fields are common to the Document management module. • Finally click to confirm The vector file (use of the browser to locate it in the file system) is the new theme to be added to the TOC. Repeat these steps for each theme to be loaded.

To load a selected theme click the button. This theme remains permanently in the TOC. To remove it: • Make the theme active in the TOC; • Select Delete theme from the Edit menu; • Click Yes in the dialog box that appears.

30

5. THE ARIPAR DATABASE

The ARIPAR 4.0 database is implemented as a single VC++ application, named ARIPAR40.EXE and involving the ARIPAR.MDB database. The User accesses ARIPAR.MDB data from several input dialogs managed by ARIPAR40.EXE. The activation of the input dialogs is performed in two ways: • by GIS menu: the User can move among records; • directly by selecting the GIS graphic element: it’s possible to display a single

record only. All the input dialog form of the database follow the conventions: • the dialog has its own title in the first row, • generally it’s possible to resize the input dialog; • the input dialog position and size are saved into Windows register and they will be

restored to the successive call; • an EXIT button is always available to quit the input dialog; • when using the default colours the yellow fields are enabled, the green fields are

disabled; • the numerical values are represented in different form (decimal or exponential

notation), but they can be entered in any format compatible with the data type. For instance a field representing the exponential value 1.e -1 can be entered as .1 (the program will take care to display it in exponential notation);

• the ARIPAR40.EXE performs the transaction operations: the User can abort the records modification by pressing the right button mouse. A dialogue window asking for confirmation will then appear. Choosing the ABORT CONFIRMATION option the modifications of the records will not be saved>

• the buttons are provided with short tips help messages, activated when moving the mouse cursor over them.

It is possible to access the ARIPAR 4.0 dialogs in different ways: • using the TABLES menu of the GIS user interface; • selecting a graphic element with the mouse. The second selection is possible for the GIS layers, i.e: • Population Areas; • Vulnerability Centres; • Plants, Pipelines, Courses, Roads, Railway; • Risk Sources; • Nodes. If the User calls for a dialog selecting a graphic element with the mouse the navigation through the records is not allowed. The navigation is possible if the User calls the same dialogs from the GIS TABLES menu.

31

5.1 Meteo Aggregation Dialog

The User can add Meteo Aggregations only when the Time Periods have not yet been defined, otherwise the User should redefine several data in some tables (i.e. Meteo table).

Input fields: Pasquill Classes Description of Pasquill classes se lects by menu

Wind Speed related to the Pasquill class (m/s). The following values are acceptable:

Pasquill class Max wind velocity A 7 m/s B 12 m/s C unlimited D unlimited E 12 m/s F+G 7 m/s

Wind Speed

Fogs 23 m/s Buttons:

Add a new row (the button appears only if there are not defined periods)

Close the dialog

NOTE: it’s possible to define up to 6 Meteorological aggregations Pasquill classes – Wind speed.

5.2 Time Periods Dialog

This dialog is used to define the more appropriate time periods over a year on the basis of the meteorological and / or population distribution data.

32

Input fields: Description Description of the Period Period % Normalised period duration. The sum of all Period duration must

to be equal to 1.

Add a new row. This button appears if there are not defined periods.

Close the dialog

5.3 Distribution of Meteorological data

ARIPAR-DB uses up to a maximum of six meteorological aggregations, each characterised by a Pasquill Stability Classes - Wind Speed values; up to 16 wind directions can be defined with their associated frequency, the North being directed on the vertical-top axis of the screen. The meteorological data are entered directly as probability of the different directions for each of the Meteo aggregations.

33

The Meteo data are displayed by Period. The current Period is shown at the beginning of the dialog. The User can select a Period from the Period - list. Buttons:

Delete all values

Fill all fields with identical values (this button appears if the all values are null)

Shows the graphical representation of the meteo data related to the selected stability class (i.e. A[7])

Close the dialog

5.4 Graphical representation of the Meteorological data

This dialog produces the graphical representation of the selected meteo data, This diagram can be saved into a JPG file for documentation purposes.

Selection fields: Period Period chosen from popup menu Meteo Aggregation Meteo Aggregation chosen from popup menu

34

Buttons:

Save the current diagram to file.

Toggle white/black backgroung color

Close the dialog

5.5 Population Categories Dialog

Input fields: Category Population Category Identifier Buttons:

Delete the selected rows

Add a new row

Close the dialog

5.6 Population Categories Presence Dialog

This dialog is used to assign, to each population category previously defined, the data about their indoor – outdoor presence probability for each time period.

35

The User can choose the requested Population Category from the Category list. The sum of Indoor and Outdoor probability must be less than or equal to 1. Buttons:

Close the dialog

5.7 Description of the spatial distribution of the population

In ARIPAR 4.0 the population distribution is being described by means of a set of polygons showing the inhabited areas. Each polygon is associated with the following data: • The user-defined Land Use class; • The number of people; • The squared cell dimensions. With this information ARIPAR generates, for each polygon, a grid; each grid cell is then associated the number of people according to the classification specified at point 1.6. The number of inhabitants for a generic polygon is given by:

Ninhab = (area of the polygon(ha)) * (Density) / Number of Cells

Input fields: Category Land Use description Population density Population density related to the current Land Use

(inhabitants/ha) Cell dimension Dimensions in meters of the square cell of the grid that will

be generated within the selected polygon Notes Notes about the current row

36

Buttons:


Add a new row

Close the dialog

5.8 Vulnerability data dialog

This dialog can be used to define the parameters of the Vulnerability models for toxic Substances. It is possible to define any number of substances and, for each substance, any number of Probits’ parameters.

Input fields: Substance Name of the Substance.

It’s possible to select another substance from the menu

It’s possible to edit the name pressing the button CAS number CAS number of substance Explosion Check this field if the substance can also lead to Explosion Fire Check this field if the substance can also lead to Fire Dispersion Check this field if the toxic substance is only toxic Some of the following fields are meaningful only for some of the selected phenomenology.

37

In case the substance is not toxic the only fields enabled are Flash Fire Threshold and Probit Effect Value Conversion Coefficient. In case the substance is toxic, not flammable, the Flash Fire Threshold field is not enabled. Probit Probit name Source We also recommend to always include in this field the

origin of the Probit model Selected Probit If this check is selected the current Probit is used for Risk

analysis. The selected Probit is highlighted by a blue selector.

Probit Coefficients Check this item if Probit coefficients are provided for the vulnerability computation. This item is mutually exclusive with the Damage Thresholds choice.

Damage Thresholds Check this item if Damage Thresholds are provided to build a vulnerability function. This item is mutually exclusive with the Probit Coefficients choice.

1st Probit Coefficient Safety Threshold

The first message is displayed by selecting the Probit Coefficients field and indicates the definition of the first Probit Coefficient. The second message is displayed by selecting the Damage Threshold field and indicates the value below which there is no damage.

2nd Probit Coefficient Certain Damage Threshold

The first message is displayed by selecting the Probit Coefficients field and indicates the definition of the second Probit Coefficient. The second message is displayed by selecting the Damage Threshold field and indicates the value below which there is for sure a damage.

3rd Probit Coefficient 50% Damage Value

The first message is displayed by selecting the Probit Coefficients field and indicates the definition of the third Probit Coefficient. The second message is displayed by selecting the Damage Threshold field and indicates the definition of the threshold value in which there is a 50% damage.

Reference Exposure Time Exposure Time for the computation of the vulnerability step function. It is enabled only if Damage Thresholds has been selected.

Probit - Effect value conversion coefficient

Coefficient used to convert the effect value (bar, kw/m2, mg/m3) in the unit measures of the vulnerability model.

NOTE: the Reference Exposure Time must be defined before defining the 50% Damage Value

38

The following fields are enabled for all outcomes: Threshold Value Limit threshold (expressed in mg/m3) below which no

dangerous effect is caused. Flash Fire Threshold Definition of the threshold (in mg/m3) below which there is

vulnerability = 1. for fast combustion of the cloud (Flash Fire).

Multiplicative Factor for the Accident Probability (Road Traffic))

This value is used during the phase of automatic generation of Tops for the Road Traffic. It can be used to increase or decrease the probability of accident involving a specific Substance to take into account specific procedures/transportation means bound to that substance.

Threshold for damage curves representation

Threshold value used by the program for the computation of the damage curve. The second field refers to the unit measure.

Note Note field. We suggest to use this field to indicated the source of the vulnerability model used and its associated time units.

Buttons:

Delete the current Substance or Probit

Add a new Substance or Probit

Close the dialog

The sub dialogs EXPLOSION and FIRE are slightly different, although keeping the same structure.

39

NOTE: It is recommended describing in the “Source” field the origin of the model used and the units measure, especially as far as the time units are concerned. In fact, the exposure time must be consistent with the unit measure used in the vulnerability model. Probit Equation Definition Probit equations have the general form: a + b ln [Cn t/m] where: a = 1st Probit coefficient b = 2nd Probit coefficient n = 3rd Probit coefficient C = Concentration of toxic vapour in the air t = Time of exposure The Probit equation coefficients can be derived from the scientific literature or using the method proposed in the TNO ‘Green Book’. Definition of Damage Thresholds As an alternative to the Probit function, the thresholds definition method can be applied. Three damage thresholds are used to build a vulnerability function “V” defined as follows:

40

V = 0 for effects less than or equal to the ‘Safety Threshold’, independently from the exposure time V = 1 for effect greater than or equal to a ‘Certain Damage Threshold’, independently from the exposure time For intermediate effect values, the vulnerability threshold is given by:

V = 0.5 * (Damage effect * T exposure ) / (50% Damage Value / T exposure ) with upper limit set to 1.

5.9 Parameters for Road Transport

This dialog allows defining some data for the automatic computation of road transport accident frequencies (frequencies of the top events): • Release Probability: allows to enter, for a given accident, the occurrence

probability of the following events: Minor Leakage, Catastrophic Rupture, and Flange Rupture.

• Accident Frequency: probability of the occurrence of an accident according to the road type;

• Threshold value for the Road Transport; the automatically generated top events with a frequency below the cut-off value will not be considered in the analysis.

Using these values, the occurrence frequency of a Top Event for the road transportation (Ftop) is computed automatically as follows: Ftop = K * Finc * Vi * L * Pr

where: K = is the multiplicative factor accounting for the specific transport procedures / means bound to a specific substance, see 1.8.

41

Finc = Accident frequency (see previous table) Vi = Number of vehicles / year on the road path, divided by the transported substance, defined in the road transportation dialogs of the ARIPAR-GIS; L = Length of the stretch (automatically computed by the ARIPAR-GIS) Pr = Occurrence probability of the specific scenario (small break, nozzle break, catastrophic break), defined in the previous table. Buttons:

Delete the selected Accident Frequency

Add a new Accident Frequency row

Close the dialog

5.10 Outcome type

The duration of the Exposure Time is required for each accident outcome (excluded those related to Explosions and Heavy gas instantaneous release). For each accident outcome it is possible to define a Mitigation coefficient that is applicable to the whole area. The Mitigation coefficient is a value between zero and one multiplying the outdoor vulnerability to obtain estimation for the indoor vulnerability. The value 0 for this coefficient stands for no protection by staying indoor with respect to the related typology, whilst a value of 1 stands for complete protection. NOTE: THE EXPOSURE TIME MUST BE EXPRESSED IN THE UNIT MEASURE REQUIRED BY THE PROBIT FUNCTION!

42

Buttons:

Copy the Exposure Time values displayed in this window to the Outcome dialog if the Exposure Time box is checked. Copy the Mitigation values displayed in this window to the Outcome dialog if Mitigation box is checked.

Close the dialog

5.11 Accident definition

The Accident list is used in the Top Event definition. Input fields: Description Population Category Identifier Value Failure rate value Buttons:


Add a new row

Close the dialog

5.12 F-N Parameters Dialog

This dialog is used to set the parameters necessary to draw the two lines on the F-N curves to describe the acceptable risk area, the not acceptable risk and the area in between generally refereed to as the ALARA area.

43

At the left the values of the X-axis (fatalities) appear. the list is not editable. At the right the user can set two lines in the F-N graph: - a line of Unacceptable Risk; - a line of Acceptable Risk. Default values are as follows: Unacceptable Risk

X1, Y1 = (1, 1.e-3) X2, Y2 = (100, 1.e-7)

Acceptable Risk X3, Y3 = (1, 1.e-5) X4, Y4 = (100, 1.e-9) - automatically determined -

Buttons:

Close the dialog

5.13 Risk Sources Definition Dialog

Data required for describing risk sources concern: • Name of the Risk Source selectable from menu. • Initiating event of the consequence event tree with associated substance and

occurrence frequency. The accident frequency is expressed as events/year for fixed installations and in events/km/year for the transportation of dangerous substances. In case of railway transportation the analyst must enter the frequency values already multiplied by the number of wagons/year corresponding to that substances. For road transport this computation is automatically performed on the basis of the census data entered at 1.9.

44

Input Fields: Risk Source Name Source Identifier Type Type of Source and Source Plant or Stretch name. Notes Notes related to the Source Initiating Event Description of the Initiating Event (chosen from menu or

entered directly). Frequency Frequency of accident in fixed installations (events/year)

or during transport (events/km/year). Substance Name of the substance involved in the accident (the

name must be chosen from menu). This field is disabled if there are defined Outcomes.

N/A Top Event Excluded from computation Outcome Press this key to call the Outcome dialog (see below). If

the button is orange the Outcome record has already been defined, otherwise the button is grey

NOTE 1: the selection of the Source to be displayed must always be made through the Find key. The field INITIATING EVENT is editable. Nevertheless a choice menu, including the most frequent cases is available:

Description

1 Class Release 1 2 Class Release 2 3 Class Release 3 4 Class Release 4 5 Pipeline Break 6 Pipe Break 7 Manifold failure 8 Vessel outflow 9 Vessel Explosion 10 Minor leakage 11 Major leakage 12 Catastrophic rupture 13 Flange rupture

Buttons:

On pressing the first button it's possible to assign to the current source the data of the another source to be selected from the list of sources that it is displayed (see 1.13.1) Note: this button appears if no top is defined

On pressing the second button activates the list of all Sources and find a specific Source (see 1.13.2)

Delete the selected record

Add a new record

45

Close the dialog

Accident Typology (Outcome). By pressing the Outcome key, the Outcome dialog is open, in which the specific accident data can be entered. For each initiating event the accident consequence event tree generates several outcomes, some of which are considered for quantification. A file including the results of the consequence analysis must correspond to each outcome chosen. The occurrence probability (Outcome) is the probability conditioned to the initiating event. Copy source The User can select a source by mouse and its top values appears at the left. It’s possible to reduce the Sources number by filter, typing a character or a string in the row at the top of the form: the list will show only the sources whose name begins for the typed character or string. Buttons:

On pressing the button it's possible to look the entire selected source property: top, outcome, fit coefficients.

Copy a source values

Close the dialog

46

Find source

The User can select a source by mouse and its values appears on Sources form. It’s possible to reduce the Sources number by filter, typing a character or a string in the row at the top of the form: the list will show only the sources whose name begins for the typed character or string.

5.14 Outcomes Definition Dialog

5.14.1 New Outcome

If the current top event does not have the same outcomes the following form appears.

The User must to define a new Outcome type:

47

5.14.2 Existing Outcome

Input Fields: Name (greyed title of dialog)

Description of the Accident. The Outcome type can be selected by menu when the User creates a new Outcome

Threshold Threshold value to consider the effect as significant (the measurement unit depends from the typology). This value is defined in the ‘Vulnerability Data’ dialog.

Occurrence Occurrence Probability for this outcome. It is the conditional probability of the outcome given that the initiating event has occurred.

Mitigation Mitigation Coefficient Occurrence probability The probability that the initiating event might occur Effect Call the FIT program for coefficients computation. If the

button is orange the coefficients have already been defined, otherwise the button is grey

Exposure time Exposure time value for the current accident outcome Flash Fire Check if the Outcome produces Flash Fire

48

N/A If this check box is active the outcome is excluded from computation

Consequence file (Fit file)

Prefix of the name of the file containing the results of accident consequences, i.e. without the aggregation code. In the fitting program section it is possible to run the fitting program for the computation of the Effect coefficients corresponding to a specific meteorological aggregation.

NOTE 1: the sum of the Occurrence probability of all outcomes for a given Top cannot be greater than 1! NOTE 2: the probabilities related to periods must sum up to 1! NOTE 2: it is advisable to use names that remind the outcome type When a new outcome is defined, its type can be selected from menu

Code Accident Typology 01 U.V.C.E. 02 CONFINED EXPLOSIONS 03 FIREBALL 04 JETFIRE 05 POOLFIRE 06 JET DISPERSION 07 HEAVY GAS CONTINUOUS RELEASE 08 HEAVY GAS CATASTROPHIC RELEASE 09 GAUSSIAN DISPERSION

The Time Exposure Coefficients table is composed by few rows (related to the specific meteorological conditions) and 1 or 2 columns (one for each coefficient). The table initially shows the values of the coefficients defined in the Mitigation dialog The first coefficient corresponds to the exposure time (expressed in the measurement units required by the vulnerability model). The second coefficient is used only in case of catastrophic release of heavy gas; the relation gives the exposure time:

T = exp (coeff 0) * R coeff 1 Buttons:

Delete the current Outcome

Add a new Outcome

Close the dialog

NOTE: in case of GAUSSIAN DISPERSION the fitting program is not used. In fact the fitting file contains only the release flow and the high of release (see A.1.9).

49

5.15 Risk Sources Definition Dialog for Road Transp ort

The User is requested to enter the Road type (from menu) and the Accident Frequency related to Road Type. A default value appears in the Accident Frequency field. New buttons:

Open the Generation of the Road Traffic Top Events dialog

Disable/enable the Automatic Top list

5.16 Generation of the Road Traffic Top Events

In this dialog the user enter, for each transported substance, the data about transport means.

Input Fields: Substance Name of the substance involved in the accident (the name must be

chosen from menu). # Vehicle Total number of vehicles (num/year) Trucks % Percentage of Truck Rimorks % Percentage of Trucks with rimork Articuled % Percentage of Articuled

DIALOG DA SISTEMARE

50

Buttons:

Automatic generation of the Top. The new Tops are added to Top Event list in the Source dialog. They are not editable and they will appears in green background colour.

Delete the selected row. The related Top Event on Source dialog will be deleted too.

Add a new row

Return to the Source dialog

5.17 Vulnerable Centres Dialog

Input fields: Name Name of current Vulnerable Centre Categories Population Category description (selected by menu) Number of people Population of current Vulnerable Centres NOTE: GIS creates the Vulnerable Centre element. Buttons:

Navigation buttons

Activates the list of all Vulnerable Centres to select a specific Centre (see 1.13.2)

Delete the current Vulnerable Center Category. If the User selected a deleting row the Find button and the Navigation buttons are disabled until the delete operation is performed

Add a new Population Category

Close the dialog

51

5.18 Population Areas Dialog

Input fields: Area description Name of current Populated Area Area Type Area Type selected from menu. Population density Population density related to the current Area

(inhabitans/ha) Cell dimension Distance (m) between two Point with population created by

GIS Population Population related to the current Area Categories Population Category description (selected by menu) % Population Population Percentage of the current Category. The sum of

all Percentage values must be 1. NOTE 1: the Population density and the Cell Dimension fields are settled by Area Type choice and their values are modifiable by User. Buttons:

Navigation buttons

Activates the list of all Areas and find a specific Area (see 1.13.2)

Deletes the current Vulnerable Centre Category.

Add a new Category Population

Close the dialog

5.19 Source Aggregation Dialog

There are 5 different types of Risk Sources: Plants, Railways, Pipelines, Ports, Roads. The related dialog contains the same fields (only the dialog title is different).

52

Input fields: Name Name of the current Risk Source Type Type of current Risk Source. This field is read only. Notes Notes field Buttons:

Navigation buttons

Activates the list of all Risk source aggregations to find a specific one (see 1.13.2)

Close the dialog

53

6. RISK CALCULATION

6.1 Fitting program

The ARIPAR program computes the accident consequences in every point of the area using the interpolation function that fits the results of the consequences calculations made off-line with programs chosen by the User. The fitting program computes the interpolation coefficients of the curve that will be used for the computation of the accident consequences in all points of the calculation grid. The interpolation functions used for each typology are described in Appendix 1. The accidents consequence files, for the computation of the coefficients, must obligatorily reside in C:\aripar.40\project\filesfit. The above dialog has two columns on its left: • CURRENT column, including the values of the coefficients currently stored in the

database; • NEW column, including the values of the coefficients computed or entered

manually. The column CURRENT is not enabled. When the dialog shows up, the values of the coefficients of the NEW column are set equal to the values of the CURRENT column. The number of the coefficients depends on the Typology. The flag MANUAL is automatically selected when the User modifies a value. It is automatically deselected when the User activates the computation of the coefficients. The form title contains the name of the accident consequence file. Its name is created following these rules:

54

• the prefix (max six characters) is defined in the Risk Source dialog, • a numerical index follows (01…05), representing the index of the meteo

aggregation it refers to • the extension depends on the typology used, as indicated in the following table.

Extension

Accident

UVC U.V.C.E. CON PHYSICAL EXPLOSIONS FIR FIREBALL JET JETFIRE POO POOLFIRE OOM JET DISPERSION DEN HEAVY GAS CONTINUOUS RELEASE NOA HEAVY GAS INSTANT RELEASE GAU NEUTRAL DISPERSION (Gaussian)

The format required by the file and the measurement unit to be used is included in Appendix 1. The rightmost black area shows a two-dimensional graph having on the x-axis the distance (in meters) from the source, and on the y-axis the Effect value (range and measurement units depend from the Phenomenology). Green circles represent the data read from the accident consequence file, whereas the fitted values are represented by a red curve. The maximum x-axis value proposed by default from the program can be edited. Selecting the LOGARITHMIC Y-AXIS flag the graph representation toggles between logarithmic and linear. The graph representing the effect value on the axis of the phenomenon, downwind, is used to verify that the interpolating functions computed do represent the phenomenon with the wanted precision. If this is not true, the number of points in the input file could be increased or the coefficients could be modified (NEW column). We recommend, however, plotting the graph for a distance equal to the maximum extension of the study area, to verify that there is no anomalous phenomena in extrapolation. Buttons:

Opens the dialog to edit the accident consequence file.

By clicking this button the interpolating curve is re-computed using the values in the NEW column (therefore this option should be used in the case of manual setting of the coefficients) or after entering the new maximum value of the x-axis.

By clicking this button the coefficients are automatically determined

By clicking this button the coefficients in the NEW column are transferred into the database, and are also assigned to the CURRENT column

By clicking this button it’s possible to link a document regarding the Consequence computation to form. The document must to be in the CONS directory

55

By clicking this button it’s possible to remove the link to document.

By clicking this button it’s possible to show the document.

Close the dialog

Accident consequence file edit

The number of columns depends on the file type. See the Appendix for column header explanation. Buttons:


Add a new row

Close the dialog

56

6.2 Fitting program GIS dialog

It's possible to call this dialog from the TABLES menu of the GIS interface. The dialog fields are, from left to right: • Substance; • Initiating event; • Outcome; • Risk Source (as defined in ARIPAR-GIS); • Fitting File (defined in the Risk Sources dialog); • Date and Time; The dialog shows the name of the fitting file automatically generated in the database. The columns are sorted starting from the left side field. It is however possible to sort by any column just by double clicking on the header. The Analyst can select any number of rows to set a name of file or to execute the fitting OPERATION. All the usual WINDOWS selection modes are allowed, using the left mouse button, possibly combined with the SHIFT and CTRL keyboard keys. An example of multiple selection can be used to assign the same file name to different scenarios. This is achieved by setting the FIT file field. By clicking the Save button the file name (with the addition of 2 digits corresponding to the class of aggregated meteo data) is assigned to all the rows selected. Buttons:

Start fitting program

The computation of the coefficients on the full set of outcomes is executed

FIT file selection

The file name is assigned to all selected rows

Close the dialog

57

6.3 Selection of Sources

This dialog allows the User to select the Risk Sources for which the risk computation is requested. For the selection mechanism the usual WINDOWS selection modes are allowed, i.e. use the left mouse button, possibly combined with the SHIFT and CTRL keyboard keys.

Input fields: Virtual source step Integration step for linear sources Buttons:

The Sources highlighted in the Risk Sources ID pane are moved to the “Selected Risk Sources” pane.

The Sources highlighted in the “Selected Risk Sources” pane are removed from it.

All the Sources of the Risk Sources ID pane are moved to the “Selected Risk Sources” pane.

All the Sources in the “Selected Risk Sources” pane are removed from it.

By clicking this button the Risk Sources calculation starts

By clicking the check procedure is executed

Close the dialog

58

6.4 Check procedure

The Check procedure verifies the correctness of the FIT coefficients and the Mitigation parameter. If the procedure detects errors it will show the following dialog. Buttons:

By clicking the check of FIT coefficients is performed.

By clicking the check of Occurrence values is performed.

Close the dialog

The dialog shows the position (Risk Source - Top Event - Outcome - Meteo aggregation) of the errors.

6.5 Risk Source calculation

By clicking the RUN COMPUTATION button the DOS procedure for the generation of the database is started. The following window is displayed from which the User can follow how the progression of the risk computation. The program process all Sources whose Identifier are included in the SELECTED SOURCES pane. The program shows in real time the status of the generation of the Area Risk displaying: • the Identifier of the Source currently processed; • the number of linear source segments processed (if applicable). At the end of the processing a message is issued. The User may interrupt the computation at any time by using the STOP button.

59

The program produces a RESULTS.MDB database file containing the Risk values.

6.6 Display of Results

The display of the results of the computation is performed through the items of the RISK menu, in which the results can be imported and the values of the local and individual risk, the F-N curve, the I-N curve and the importance of the sources can be displayed.

60

7. REPORT WRITER MODULE

ARIPAR 4.0 provides a specific tool for supporting the reporting of the area risk analysis. The User can prepare the different sections of the report on risk analysis indicating the points where images and database query results have to be inserted. The result is an editable Word file.

The sequence of Document Name field is the same document sequence of the final report. The User can edit the document by the Word key:

The <ARIPAR> SOURCE.JPG is a metacommand: the program will insert the image named SOURCE.JPG and stored in the directory C:\ARIPAR\PROJECT\DOC).

61

Input fields: Insert Select if the current document will be inserted in the report Document name Name of the section of the report

Insert a new row in the current position

Scroll up the current row

Scroll down the current row

Show the final report

Prepare the final report (stored in C:\ARIPAR.40\PROJECT\DOC) linking all selected documents and adding the images.

Delete the current row

Add a new row at the bottom

Close the dialog

It is possible to insert into the documents some database query results using the following metacommands: <ARIPAR> POPULATION.HTM List of Population Categories <ARIPAR> PROBIT.HTM List of Probit coefficients for Substances used in

the analysis <ARIPAR> SOURCES.HTM List of Risk Sources of the analysis

62

8. PROJECTS MANAGEMENT

The PROJECT program manages the ARIPAR system. The User can: • create a New Project; • Open an existing Project; • Duplicate a Project; • Delete a Project; • Change the Project Name. A project is made up by all data including all vector and raster maps. A project is stored in the C:\Aripar.40\project. Moreover the User can perform other operations, e.g.: • select a Language; • run the ArcView program (main interface); • select the dialogs and fields colour palette for the interface. The activation of PROJECT program is performed by double-clicking with the mouse on the icon representing it. The main view is displayed:

8.1 Toolbar

Button Name Action Performed 1 New Create a new Project 2 Open Open an existing Project 3 SaveAs Duplicate the current Project 4 Delete Delete an existing Project 5 Project Name Set or change the Project Name 6 ArcView Run ArcView program with the current Project 7 Exit Exit program

1 2 3 4 5 6 7

63

8.2 Dialog buttons

Each input dialog has two button:

Perform the operation (i.e. create, open, delete or rename a Project)

Close the dialog

8.3 Menu Projects Management

New Project: create a new Project (toolbar button 1). The name of new Project can

be defined in the following dialog: Open Project: open an existing Project (toolbar button 2). The Project can be

selected from the project list:

64

Project SaveAs: duplicate the current Project (toolbar button 3). The name of the

duplicated Project can be defined from this dialog: The duplicated Project will be the new current Project. Delete Project: delete an existing Project (toolbar button 4). The Project can be

selected from the project list:

The program asks for a double confirmation before cancelling a project, since the consequence is the permanent loss of all data. Project Name: rename the current Project (toolbar button 5).

65

Run ArcView: Run ArcView program (toolbar button 6). The ArcView program starts with the current Project and the Project module is automatically closed .

Reset Aripar data : the form positions stored in Windows register are deleted. Exit: exit program (toolbar button 7).

8.4 Menu Configuration

8.5 Menu Colour Selection

The User can customise the colours of the ARIPAR interface.

Text Foreground of field (editabled or not) Text Background Background of editabled field Highlighted text Label text Fixed text Background of no-editabled field Window Background Dialog Background

The color selection is performed by a Windows standard dialog color definition:

66

NOTE: the Windows standard dialog language depending of the User language. The User can also choose the Windows standard colours (grey and white) and the ARIPAR standard colours (black text, yellow and green background respectively for editable and not editable field).

67

APPENDIXES

A.1 Basic Equations of the ARIPAR Methodology

Public authorities and private companies adopt Quantitative Area Risk Analysis (QARA) when major risks posed by large industrialised sites have to be examined and risk-related decisions have to be taken. These decisions are related to e.g. process safety, the identification of preventive and protective measures for risk reduction; land-use planning, the “safe” siting of residential quarters or new industrial plants; territorial emergency planning, the determination of strategies to protect people, the environment and assets during an accident. This practice has recently been confirmed and sanctioned by the Community Directive 96/82/EC, as it is the basis requested by art.12 for setting out a correct policy of Land Use Planning (LUP). Essentially three types of information are contained in a risk measure: The occurrence frequency/probability of an accident or of the event chain which causes the accident; The kind and distribution of physical effects responsible for the reference damage (thermal radiation in fires, overpressures in explosions, concentration/dose absorbed in toxic releases); The relation between physical effect and damage extent. When societal risk is considered, the information on the impact area must include population distribution and location of vulnerability centres (hospitals, commercial centres, schools,..) in order to evaluate the number of human beings suffering the damages. Territorial information, such as the land-use (urban, residential, rural,..) and its average meteorological conditions are implicitly considered in defining the population distribution and frequencies and consequences of accidental scenarios (for instance roughness, confinement degree, ignition probability). Note that information on soil composition and stratification, surface or underground water typologies are not requested because the cited risk measures do not permit to describe damages to the environment. Only recently the legislation requests safety reports which put in evidence such type of damages and at present no index is generally accepted to describe globally effects on human beings and environment components. Indexes based on a Fuzzy Set approach, which put together the severity of damages to different resources, have been proposed; they however are not presently widely accepted. Similarly, chronic effects of long term releases and occupational health issues are not included in the risk measures adopted. These introductory statements make clear that when the risk assessment of an industrial area is performed, the requested evaluations are not simply the sum of the risk analysis of each industrial plant but imply to account for the complexity introduced by interconnections among all sources and the territory. In a QARA procedure the choice of the impact area is the first step: the preliminary choice has to be verified and, if necessary, corrected after executing the analyses. Apparently this implies an iterative procedure, but in practice the first choice is conservative and includes often-inhabited centres which are not subjected to significant risks. Obviously the impact area of transport by road and by railway is

68

greater since it involves crossed territories but the traffic density of hazardous substances and hence the associated risk is surely higher near industrial site On the cartography of the impact area information to be shown are plants, roads, harbour, railways, pipelines and, as outlined above, information on population. The risk sources inventory is the second step of the QARA: a complete quantitative knowledge of dangerous substances processed and transported in the area allows to collect data useful to perform source risk analyses: the collection for plants when safety reports are available is relatively simple, more complex is finding the amounts of transported substances and above all establishing the used routes. The assessment of risks posed by each single source begins with the identification of a set of likely accidental events and continues with the evaluation of all occurrence frequencies and consequences. No words are necessary for recalling well-known procedures and tools for risk analysis quantification; on the contrary a mention has to be given of rules requested to guarantee the technical validity of the results. In particular a common set of methods, for identifying sources and for simulating physical consequences, should be used to compare results and ranking source importance. This last evaluation step transforms the results of safety analyses of plants and transports in a large set of pairs of frequencies and consequences of accidental scenarios. It’s up to the reassembling model to combine them in order to produce risk measures for the whole impact area. Equations combining such pairs are different if point sources (plant top events) or linear sources (transport routes) are considered, because the location of accidents “travels”, in the latter case, on road, railway, pipeline or ship routes. If P is an area point, local risk is evaluated by:

( ))1())(

1 1 1 1

(,,,

_

/,,1

,∑ ∑ ∑∑∑= = = =

→=

=N

i

iN

j

N

cv

N

PScvjiscvji

N

ssii

I CV v

v

vv

ST

xvppPRLθ

θθθαλ

for point sources, and by

( )

∑ ∑ ∑∑∫∑= = = =

→=

=l I CV v

v

vv

STN

i

iN

j

N

cv

N

Pdlcvjiscv

l

ji

N

ssiit dlxvppPRL

1 1 1 1

(,,,

_

/,,1

, )2())(θ

θθθαλ

and for linear sources. Where: αi,j is the occurrence probability of accident j, conditioned to occurrence of top i ( i = 1,..N, j = 1,…NI(i) ) λi is the occurrence frequency of top i pi,s is the probability that top i occurs in season s (the value is equal to 1/4 if an uniform annual distribution is considered), s =1,…NS

69

svcvp /,θ is the occurrence probability of the cv (cv = 1,…Ncv) pair “wind velocity-

stability class” in direction θv, conditioned to season s; θv = 1,.., Nθv

In equations (1) e (2) v_

is the average vulnerability (the fatality probability) in P due to all accidental scenarios whose direction is included in a sector of the wind rose having θv as bisector. It follows the definition of an average accidental scenario, whose vulnerability is given by

v x v di j cv S dl Pset v

i j cvv v

set v

_

, , , ( ).

, , ,( ) ( ).

θ θθθ

θ→ = ∫1

3

It is worth noting that eq. 1 e 2 do not contain any information on the population at risk, which, on the contrary, will be included in the correspondent individual risk evaluation. In fact each location of the geographical area can be occupied by persons that can or cannot be present in a given season, during day or night, and, if present, can be outdoor or indoor. These conditions define ‘categories’ of population, sharing the same probability of presence. Because the presence probability may significantly reduce the vulnerability of a category in each scenario, a correct evaluation of individual risk requires to explicitly consider how the top event depends on day/night, through the probability pg, and what is the probability of a person to be indoor or outdoor during a specific season, during day or night, through pio/s/g. Obviously the indoor exposure mitigates the physical effect of the scenario, so that a specific factor has to be defined iocvji v ,,,, θβ .

With these considerations, we have the following equation:

( )( )4)

)(

1 1 1 1,,//(,,,

_

/,,

2

1,

1,∑ ∑ ∑∑ ∑∑∑

= = = =→

==

=N

i

iN

j

N

cv

N

iojiio

catgsioPScvjiscvji

ggi

N

ssii

cat

I CV v

v

vv

ST

pxvppp

PRIθ

θθθ βαλ

which describes the geographic distribution of individual risk for each category of person. As previously said, societal risk can be represented by F/N curves, a measure of the societal impact of all accidental scenarios; in order to build the different contributions, the attention has to be focused on an average accidental scenario occurring in S; its frequency is

Fsc(i,j,s,g,cv,θθθθv) = λ α θi i s i g i j cv sp p pv, , , , / (5)

The population subject to damages is distributed on the impact area or concentrated into the so-called Vulnerability Centre e.g. hospitals, churches, stadium, supermarkets. In order to perform calculations, the distributed population too is aggregated in points of a grid and the number of fatalities results from:

70

)6())cv,g,s,j,(i, ,,//(,,,

_

1ioji

io

kgsioPScvji

P

N

kkvsc pxvNN

efv

ef

cat

βθ θ ∑∑∑ →=

=

where Pef is the set of points where the physical effect of the scenario is not negligible1. The pairs of Fsc and Nsc obtained are the basic elements for producing the cumulative curve F/N. With similar evaluations the F/N curves of transports can be calculated, by conveniently partitioning each linear source into segments. A complete and detailed procedure of reassembling risks due to many sources cannot forget the importance of domino effects, because new accidents in the industrial area could be produced from an initial top. The chain here reported Physical explosion of a vessel ⇒ overpressure ⇒ damage to an atmospheric tank ⇒ release of a toxic liquid ⇒ pool evaporation and dispersion of a toxic cloud is an example of different effects (overpressure and toxic load) and consequently of different probabilities of fatality in the impact area. A simple way to consider domino effects has been suggested from the outlined procedure. The top events of plants are assumed as the vulnerable locations of the plant themselves and only these locations are considered as source or target of domino through the use of interaction curves, each of them defined as “locus of points whose distance from a physical location of a top event is the greatest among those resulting from defined threshold values of effects of radiation and overpressure”. Equations (1) to (6) give a synthetic picture of the risk measures clearly showing the great amount of information involved. The global impact on the territory could be changed if it does not satisfy tolerability criteria and the changes can take advantage from the possibility to disaggregate contributions of plants, substances, risk sources, and of all the parameters which strongly influence the results, as will be shown in Section 4.

1 An effect is negligible if threshold values are not exceeded.

71

A.2 Interpolating Functions

The accident consequences are computed by ARIPAR through functions including adaptive parameters, which fit the results of consequence analysis programs run off-line. The results of consequence analysis must be stored into suitable formatted files, which are imported by the FIT module. These files represent the interface between ARIPAR and the consequence analysis package preferred by the user.

A.2.1 Consequence Computation Functions

The interpolating functions implemented in ARIPAR are shown below, where: R = distance from the accident source θ = angle formed by the line joining the source-point with the direction of the

wind a,b,…,m = adaptive parameters

A.2.1.1 Unconfined Explosion (P = overpressure):

A.2.1.2 Physical Explosion (P = overpressure):

R

aRP =)(

dR

baRP

c ++=)(

Point of the area where the risk has to be

Point of the area where the accident occurs Wind direction

R

ϑ

72

A.2.1.3 Fireball (I = thermal radiation)

A.2.1.4 Jet fire (I = thermal radiation):

A.2.1.5 Poolfire (I = thermal radiation):

A.2.1.6 Gas Jet Dispersion (C = concentration)

cR

baRI

++=

2)(

θ

θ

cos

:1

),(2

RX

Xz

wherezczb

aRI

==

⋅+⋅+=

)ln(

:

),( )()1( 322

f

Rz

where

eRI zezdzcba

=

= ⋅−⋅−⋅−⋅⋅− θθ

73

A.2.1.7 Heavy Gas Dispersion for Continuous Release from Pool (C = concentration)

A.2.1.8 Heavy Gas Dispersion for Catastrophic Release (C = Concentration)

[ ])(;0max

sin

cos

)(

)(

)(

:

)(),()(2)(35.1

22)(4

xzz

Ry

Rx

egeexz

xcxd

xaxC

where

exaCRC

xhxf

d

ba

xz

Z

xd

yxz

=⋅=⋅=

⋅+⋅=⋅=

⋅=

⋅=

⋅⋅

⋅⋅

+−

θθ

θ

[ ]byY

sinRy

Rx

ixxs

xxgfxsxb

xdx

exC

where

exCRC

e

xcxbaa

Y

a

−=⋅=⋅=

−⋅⋅−=

⋅+⋅+⋅=

⋅=

=

⋅=

⋅+⋅+

−

;0max

cos2

))(10000arctg(2)(

))(ln()ln(()()(

)(

)(

:

)(),(

2

)ln()ln(

2

θθ

ππ

σ

θ σ

74

A.2.1.9 Neutral Dispersion (Gaussian)

The a and b coefficients represent respectively the release flow and the release height (see A.1.9).

θθ

ππ

θ

sinRy

Rx

hzgzg

xZ

xR

m

xz

exC

where

exCRC

dZcZbZa

zlizgzfezg

n

a

anRy

⋅=⋅=

−⋅∗−=

==

=

=

⋅=

+⋅+⋅+⋅

⋅+⋅+⋅+⋅−

⋅−

cos2

))(arctg(2)(

)(log

10)(

)ln(

)(

:

)(),(

10

)3.02.01.0(

)()()())(1(

223.2

222

22

2

2

2),( z

by

y

eev

ayxC

windzy

σσσσπ

⋅⋅− −

⋅⋅⋅⋅⋅⋅

⋅=

75

A.3 Input Files for the Computation of the Adaptive Coefficients

The coefficients a,….,m used in the interpolating functions listed in A.1 are computed by the FITTING program starting from the input files that contain, in a suitable format, the consequences vs. downwind distance from the accident and the angle with respect to the direction of the wind. These files have a free name built from a max of 6 characters, chosen by the analyst, followed by the characters ’01,…,05’ identifying the meteorological aggregations and a specific extension indicating the phenomenology. For instance, valid consequence file names are: nnnnnn01.JET nnnnnn02.JET ……….. The files are always, except in the case of the Gaussian dispersion, formed by a number of rows equal to the distances used in the consequence computation, each row following the template: xxxxxx,yyyyyy,zzzzzz Each row represents the value of the consequence at a given distance, xxxxx from the source (in meters); and the other two fields represent the consequences as will be specified below. The fields in each row must be comma-separated. These files must be stored in the C:\ARIPAR\FILESFIT directory.

A.3.1 Unconfined Explosion

Input file name: *.UVC File format: r,p where: r distance from the source [m] p overpressure [bar ] Example: 10,0.2 20,0.15 30,0.11 50,0.07

76

250,0.014 ….. , ……..

A.3.2 Physical Explosion

Input file name: *.CON File format: r,p where: r distance from the source [m] p overpressure [bar ]

A.3.3 Fireball

Input file name: *.FIR File format: r,i where: r distance from the source [m] i max radiation at ground [kw/m 2] Example: 1,27.6 50,27.1 101,25.7 201,21.35 301,16.6 ….. , ……..

A.3.4 Jet fire

Input file name: *.JET File format: r,i

77

where: r distance from the source [m] i radiation at ground [kw/m 2]

A.3.5 Poolfire

Input file name: *.POO File format: r, α, i where: r distance from the source [m] α anomaly (angle between the radiation measurement point and the wind speed direction) [degrees] i radiation at ground [kW/m 2] The values of α must be the same for each value of r. We suggest to always putting as last point the one corresponding to the safety radiation value (usually 1.6 kW/m2). Example: 2,0.0,33.2 2,15.0,32.8 2,30.0,31.8 2,45.0,30.3 10,0.0,10.0 10,15.0,9.86 10,30.0,9.42 10,45.0,8.79 ……… 25,0.0,1.9 25,15.0,1.84 25,30.0,1.80 25,45.0,1.78

A.3.6 Gas Jet Dispersion

Input file name: *.OOM File format:

78

r, Ca(r), D(r), Z(r) where: r Downwind distance from the source [m] Ca(r) Concentration on the axis [mg/m 3] D(r) Diameter of the smoke cloud [m] Z(r) Height of the axis of the smoke cloud [m] Example: 10.1,28300.,2.6,16.1 60.9,1615.,10.6,15.6 210.8,195.5,30.5,14.8 …………………..

A.3.7 Heavy Gas Dispersion with Pool Formation and Evaporation

Input file name: *.NOA File format: r, Ca(r), Sy(r), b(r) where: r Downwind distance from the source [m] Ca(r) Concentration on the axis [g/m 3] Sy(r) Parameter σy b(r) Cloud half-width [m] Example: 20.0,733.7,17.84,260.77 40.0,230.9,28.2,325.2 60.0,112.9,36.8,363.8 …………………..

A.3.8 Heavy Gas Dispersion – Catastrophic Release

Input file name: *.DEN File format: r, R(r), Ca(r) where: r Downwind distance from the source [m]

79

R(r) Cloud radius [m] Ca(r) Concentration on the axis [kg/m 3] Example: 1.0,60.02,0.156 1.3,60.63,0.156 11.6,85.5,0.14 …………………..

A.3.9 Neutral Dispersion (Gaussian)

Input file name: *.GAU The file is composed of a single row with the values: Q, z where: Q Release flow [kg/s ] z Release high [m] Example: 50.0,10.

Aripar4_RefMan

Documents

ctrl keyboard

band raster

report writer

selected rows

document management

site layout

navigation

current theme