Selected Presentation from the INSTAAR Monday Noon …instaar.colorado.edu/other/seminar_mon_presentations/peckham_2002.pdfPeckham presentation (0.9 Mb PDF) Abstract ARHYTHM is a distributed

Selected Presentation from the INSTAAR Monday Noon Seminar Series.

Institute of Arctic and Alpine Research, University of Colorado at Boulder.http://instaar.colorado.edu

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25 Nov. 2002 Scott Peckham, INSTAAR, Email: [email protected]" A new distributed hydrologic model based on ARHYTHM and RiverTools."Seminar given at INSTAAR, University of Colorado. Copyright 2002 Scott Peckham. All Rights Reserved.Peckham presentation (0.9 Mb PDF)

Selected Presentation from the INSTAAR Monday Noon Seminar Series.

Institute of Arctic and Alpine Research, University of Colorado at Boulder.http://instaar.colorado.edu

http://instaar.colorado.edu/other/seminar_mon_presentations

25 Nov. 2002 Scott Peckham, INSTAAR, Email: [email protected]" A new distributed hydrologic model based on ARHYTHM and RiverTools."Seminar given at INSTAAR, University of Colorado. Copyright 2002 Scott Peckham. All Rights Reserved.Peckham presentation (0.9 Mb PDF)

Abstract

ARHYTHM is a distributed hydrologic/thermal model that was developed by Hinzman and colleagues (Zhang et al., 1999)for use in both arctic and nonarctic watersheds. It incorporates a number of important physical processes, includingsnowmelt, evapotranspiration, precipitation, subsurface (multi-layer Darcy-law) flow, overland flow and channel flow. Thesnowmelt process can optionally be modeled with either the degree-day or energy balance method. Similarly,evapotranspiration can be modeled with either the Priestley-Taylor or energy balance method. The model is physically-based and has been tested for several watersheds on Alaska's North Slope. It consists of a geometric component thatextracts a D8 flow grid from a DEM, in addition to the dynamic modeling component.

During the past year, the dynamic component of the ARHYTHM model has been rewritten and significantly extendedusing IDL (Interactive Data Language) and endowed with a user-friendly graphical interface. This interface has beendesigned to make it easy for users to code up new methods for any of the physical processes. Rather than rewrite thenetwork extraction component, the model now draws on the powerful capabilities of RiverTools for the geometriccomponent and visualization of results. Together, RiverTools and this new version of the ARHYTHM model make apowerful hydrologic modeling toolkit.

A New Distributed Hydrologic

Model Based on ARHYTHM and

RiverTools

Dr. Scott D. Peckham

University of Colorado, Boulder

December 8, 2002

TopoFlow

Acknowledgements

Colleagues at the University

of Alaska in Fairbanks:

Matt Nolan, Larry Hinzman,

and Bob Bolton

And at the USGS in Boulder:

J. Dungan Smith and David Kinner

What is RiverTools?

What is ARHYTHM?

RiverTools is a commercially-sold application for digital terrain

and river network analysis. It is a full-featured Windows-style

program with raster and vector GIS capabilities, ability to import

many DEM formats, advanced visualization and analysis tools,

and a wide variety of additional tools for working with DEMs

and flow grids. (www.researchsystems.com)

ARHYTHM is a spatially-distributed hydrological model that

incorporates thermal processes for use in the Arctic. It is physically

based and is written in Fortran.See Zhang, Z., Kane, D.L., Hinzman, L.D. (2000) Development and application of a

spatially-distributed Arctic hydrological model and thermal process model (ARHYTHM),

Hydrol. Proc., 14, 1017-1044.

Design Criteria for TopoFlow

¸ User-friendly interface

¸ User-extendible

¸ Open-source code

¸ Structured, consistent, clean

¸ Different timesteps for processes

¸ Multiple output options:

Grid sequences, hydrographs for

multiple outlets, etc.

¸ Flexible input options:

Any input variable can be a scalar or grid.

Note: IDL’s dynamic data typing is perfect for this.

Overall Design Paradigm

Physical Process: (e.g. Snowmelt, ET, Overland Flow, Channel Flow)

Method: (None/Simple/Complex, e.g. None, Degree-Day, Energy Balance)

Formulas: (These define the method. Need enough to solve for all

the output variables. Implemented as functions.)

Variables: (Input/Output, Scalar/Grid, Deterministic/Random)

Other Issues:

Timesteps

Stopping Criteria

Output Methods

Multiple Methods per Process

Degree-DayNone Energy BalanceSnowmelt

NonePriestley-Taylor Energy BalanceEvapotran.

Kinematic WaveDynamic WaveChan. Flow None

Each method has a similar set of dialogs to specify

or collect input and output variables. Any process

can be turned off.

TopoFlow Main Dialog

Snowmelt: Energy Balance Dialog

Uniform Precipitation Dialog

Subsurface Flow Dialog

Output Methods

Trapezoidal Channel Cross-Sections(attributes can depend on HS Order)

Flow Resistance Options: Manning’s Formula (n)

Law of the Wall (z0)

Special Cases: Rectangular: width = 0

Triangular: angle = 0

Treynor Watershed Surface Plot

Treynor Watershed Surface Plot

Treynor Watershed, Iowa (0.43 sq km)

Simulated Hydrograph for

Treynor Basin and 6/7/67 Storm

Simulated Hydrograph for Treynor

Basin and 6/20/67 Storm

Simulated Hydrograph for Treynor

Basin from Steady Rain

Treynor Hydrographs vs. Data

Distributed Discharge Animations

The animation could not be included

In this PDF document, but might be

Available on the INSTAAR website.

Extending TopoFlow:Steps for Adding a New Method

Suppose a user with basic programming skills wants to add a

new method for modeling a given physical process.

1. Add string to the droplist of methods in code for main dialog.

2. Add name of routine to call when that method is selected.

3. Add any new input variables the method needs to the structure

which contains all the input variables for given method.

4. Edit the “method caller” routine to add the new method.

5. Starting with code for an existing method’s GUI (viewed as

a template), edit it to collect input variables that are needed by

the new method.

6. Write a set of functions corresponding to the formulas that

define the new method. Model these after examples.

Summary

- TopoFlow is a new, user-friendly and user-extendible

toolkit for spatially distributed hydrologic modeling.

- Although similar in spirit to models like CASC2D

and MMS, it offers several advantages, such as the

ability for any input variable to be provided as a scalar

to be distributed uniformly or as a spatial grid.

Similar support for grid sequences is planned.

- It’s intuitive, open-source, structured design provides

an environment for both research and education.

UAF Campus

Flow Lines for Treynor Watershed

High-Level Pseudocode- Create input files with RiverTools

- Launch the GUI and collect all input variables

- Call Main Program

For each timestep do begin

For each physical process do begin

If it is time to update the process then

Get contributions using formulas for chosen method

Endfor

Add up the contributions

Update dynamic variables

Save selected variables in files

Endfor

- Exit Main Program

- Create plots using the output files

Measuring Input Variables

Anatomy of TopoFlow

Main Dialog

Main Dialog Event Handler

Main Program

For each method:

Dialog to collect input variables (+ Event handler and Help)

Dialog to specify output variables (+ Event handler and Help)

Dialog to list formulas for the method

For each physical process:

“Method Caller” routine (called by Main Program)

Data structure that stores all parameters for that process.

A Collection of Utilities

And Thank You, Starbucks

A programmer is a machine for

turning coffee into software

A mathematician is a machine for

turning coffee into theorems.

Simulated Hydrograph for Treynor

Basin from Snowmelt