Risk Analysis Of Cultural Resource4th June2

Risk Analysis of Cultural Resourcewithin Floodplains of Snoqualmie Valley

Presented By Odra Cárdenas

Shweta Bhatia Gupta

The impacts of flooding in King County are far ranging and pose significant threats to public safety and regional economic viability, but it also threatens the continuity of cultural resources due to the devastating effects.

The cultural heritage along the fertile Snoqualmie river valley comprise quarter of the entire county is subjected to frequent and devastating floods as recently as in year 2006 seasonal flooding.

The Project

King County Historic preservation program has recently launched major rural preservation and the project, is a pilot for developing a model of integrated data base for a countywide assessment of historic properties leading to a management plan that will provide a more comprehensive means of treating the county’s significant historic properties during natural disasters.

Sponsored By

The Project

In the last 16 years, the Snoqualmie valley

have experienced four of the worst floods on record,

including November 06's record-breaking deluge.

Within the Snoqualmie River basin floodplain

there are a total of 1,880 parcels. This is approximately 40

percent of the total number of parcels in King County

floodplains (4,738).

There are structures at risk from flooding on 867 of these

parcels. The depth of flooding varies depending on

location.

Why Snoqualmie RiverThe Site

To develop a GIS model that provides a risk

analysis matrix that analyzes the risk exposure

from natural hazards for unincorporated

heritage properties and archeological sites in the

Snoqualmie River Flood Plain.

The model will provide finer spatial detail and

will be able to be used to replicate the analysis

for other areas of King County.

Goal

Phase I Objectives: Enrich the inventory (Data sets) of the cultural resource within unincorporated King

County area of Snoqualmie floodplains. Explore other datasets that may correlate with the mapped data. Correlate data sets and map the outfalls. Provide risk analysis matrix and create models to analyze risk exposure from natural

hazards for heritage properties. Create an integrated database.

Phase II objectives: Manipulate data so that it can be used in future modeling applications and analysis; Mapping information about risk levels for each property. Formulate hypotheses regarding effects of the mapped outfalls; Provide report on approach and outcome of analysis.

Objectives

Methodology

Research Resource identification

Data Gathering Defining dataset

DefinitionOf Matrix

Data accumulation

Actual project plan

Work breakdown structure

Task Division

Monitoring the process

Status reports Work quality

Time schedule

Database design

Creating feature set Digitization

Reclassification

Analysis

Process

Model Building

Reporting

Management

Focus of today’s Presentation

A GIS Model for analyzing risk for unincorporated historical resources in the

Snoqualmie River Floodplain of King County

A detailed Risk Analysis for the historical resources of King County (in the

Snoqualmie River floodplain)

A Instructions on how to use the model and Results report on the approach,

methodology and outcome of the analysis.

Scope

GIS Model Feature

Historic DistrictIDLocation Info Characteristics

HistPropretyID

HistoricDistrict

PolygonHistPropretyID HistDistrictIDHistMunicipleIDCharacteristics SummaryCharacteristicDetail

HistoricProperty

Point

HistPropPolygon

HistPropretyID

HistMunicipalityPolygon

PolygonHistPropretyIDHistStructureIDCharacteristics SummaryCharacteristicDetail

HistStructurePolygonPolygon

Polygon

HistElementIDHistPropretyIDLocation Info

HistElemPoint

Point

HistElementIDHistPropretyIDLocation Info

HistElemPolygon

Polygon

Object

Feature

HasSites

ArchSite Grid

¼ Mile grid

Historic Architecture

ArchPropertyIDLocation InfoCharacteristics

Archaeological District

Polygon

ArchPropertyID

ArchProperty Polygon

Polygon

ArchPropertyIDSmithsodianIDArchDistrictIDProperty NameLocation InfoCharacteristics SummaryCharacteristicDetail SiteDetails

Archaeological Property

Point

Feature

Feature

Archaeological Site

Project Scope

1 2

3 4

5

1. DATABASE2. DIGITIZATION3. MATRIX4. MODELS5. MAPS/ ANALYSIS

Project Scope Data Base 1Flood Data Set Flood Plain Flood Way

Water Bodies

Contour Data 5ft Contour 2ft Contour

Contour TINContour _ Merge

Historic Site Point

Historic Site Structure Parcel KCZoning

Admin Data

Models

Flood Plain Raster

General Analysis

Parcel Analysis

Modelwoflood Analysis

Structure Analysis

Result Raster Set

Parcel Flood Parcel Soil Parcel Slope

Flood Plain uniSoil 15Slope

Flood pl reclassSoil reclassSlope reclassFinal Result

Zone st –Par Zonal St- MinZonal St- Mean

Project Scope Digitization2A polygon shapefile replaced the existing point shapefile indicating the historic site, but not individual structure within the site.

The fields were decided on the bases of inventory documents provided for each site.

Point Feature Polygon Feature

Project Scope Matrix 3

Structural Risk Percentage Breakup

40% ,5%StatusArchitectural Style

20% Structural system

And Material

20% Structural Condition

15% Site Condition

Foundation Type 40%

Cladding Type 20%

Roof Type 20%

Roof Material 20%

Accessibility 30%

Extant 30%

Change in Use 40%

Project Scope Matrix 3Structural Material and Construction Type 20 % Contribute Ranking ScoreFoundation Type (50%)Conc. Poured 1 10Post & Pier 2 20Conc. Block 3 30 Log 4 40 Stone 5 50

Cladding(30%)Stucco 1 6Brick, Stone 2 12Log, Hr.Wood siding, Rustic drop,Wood Shingles 3 18Board and Batten, Vertical Board, Asbestos/Asphalt 4 24Vinyl/Aluminium Siding,Metal 5 30

The Matrix was prepared based on the consequence and likelihood for each contributor,i.e. structural material (20%), This in turn provided a ranking defining the score of each sub-set i.e. foundation and cladding material.

Project Scope Model4Mapped Results

Analysis Model With/without Floodplain consideration

Analysis Model At Parcel Level

Analysis Model At Structural Level

Mapped Results

Mapped Results

Risk ImpactProb.

Mitigation Contingency

Field population must be done manually and is time consuming

High LowDistribute the work between

members. Reduce study area.

It is necessary to digitize polygons of the historic resources since they are currently in point form. To digitize we need reliable

aerial photographs.

High LowContact different resources to get

aerial photographs. Use the point dataset or parcel dataset,

but the results will be less accurate.

The results might not be significant Low HighTry to include a variety of historical

resources.

Talk to sponsor on the probability of this risk (the importance of the project resides

on the methodology and model, not so much on the results)

The sponsor shows little interest in the project.

Low HighConstant communication with the

sponsor.

The team will look for other sources of information aside the sponsor and will

make own decisions on the project.

Not finishing on time the phases of the critical path

Very High LowUse Microsoft Project.

Leave slack on the programmed activities.

Reduce study area.

Risk And Challenges

Risk And Challenges

Data FormatsData Conversion Data Generation The Process Keeping up with the Critical Path Scale of the AnalysisLoosing a team mate !Communication – Inside and Out

Combination: GIS – Other Tools High Data dependency: But better the data does not

guarantee better results

Data Verification

Importance of the Team……..

Lesson Learned