GIS Hydro '98 - Water Quality

Introduction

Water quality in a river, lake or estuary is described by the advection-dispersion equation with additional terms to define decay and transformation of chemicals.  Another area of concern is pollutant loads.  Loads can be obtained by multiplying flows by Expected Mean Concentration (EMC) estimates.

This module includes a series of Avenue scripts prepared by Ferdinand Hellweger and Ann Quenzer to describe the movement of pollutant loads over the landscape and their connection with segments of a receiving water body.  The exercise "Nonpoint Sources in the Mission Basin" begins by connecting the river network with the bay system.  A runoff grid is calculated by inserting a precipitation grid into a series of runoff equations calculated in Ann Quenzer's thesis: "A GIS Assessment of the Total Loads and Water Quality for the Corpus Christi Bay National Estuary Program."  The land uses are associated with an EMC value in the runoff.  An EMC grid is calculated and multiplied with the runoff grid to produce a land surface loading grid.  A weighted flow accumulation is calculated using the loadings grid as the weight grid to determine the nonpoint source loadings to the river network and bay system.

This module of the CD also documents BALANCE, map based surface water quality modeling software developed by Ferdi Hellweger and David Maidment. The system runs inside ArcView and is written in Avenue programing language.

Resources on this CD

Documentation:

• BALANCE - Map Based Surface Water Quality Model

Exercises:

• BALANCE Salinity Modeling Exercise
• Nonpoint Sources in the Mission Basin
• Agrichemical Transport in the Iowa-Cedar Basin Exercise

Presentation:

• City of Austin Water Quality Master Planning - GIS Model (Overheads) prepared by David Maidment, Francisco Olivera, Mike Barrett, Christine Dartiguenave and Ann Quenzer, and sponsored by the City of Austin, Texas.

Related:

• Benaman, J., N.E. Armstrong, and D.R.Maidment Modeling of Dissolved Oxygen in the Houston Ship Channel using WASP5 and Geographic Information Systems, CRWR Online Report 96-2. This report shows how to construct mean annual pollutant loadings from the land surface in the City of Houston and to model their impacts on receiving waters in the Houston Ship Channel. It uses a linkage of input and output files between Arcview and WASP5 to achieve the water quality modeling in a GIS framework.
• Mizgalewicz, P.J. and D.R.Maidment, Modeling Agrichemical Transport in Midwest Rivers Using Geographic Information Systems, CRWR Online Report 96-6.  This report documents Pawel Mizgalewicz's PhD dissertation.  His dissertation research was aimed at generalizing the results of small watershed scale water quality research to the river basin scale by providing a map-based simulation model for monthly flows, concentrations, and loads.  The application region for this methodology is the Iowa-Cedar Basin in the Midwestern United States.
• Dartiguenave, C., Water Quality Master Planning for Austin, CRWR Online Report 97-6.  This is Christine Dartiguenave's master's thesis report.  It documents her research efforts in modeling water quality for the city of Austin, TX.
• Quenzer, A.M., A GIS Assessment of the Total Loads and Water Quality for the Corpus Christi Bay National Estuary Program, CRWR Online Report 98-1.  This is Ann Quenzer's masters thesis report.  It documents her research efforts for modeling water quality in the Corpus Christi Bay system.

Programs:

• BALANCE Project File: balance.apr
• Nonpoint Sources Project File:  misbasin.apr
• Avenue scripts associated with Nonpoint Sources Exercise: concgrid.ave, connect.ave, loadgrid.ave, rogridland.ave, wfacgrid.ave

Data:

Attention PC CD Users:   The GIS (ArcView) files on the CD are read-only. To run the exercises you will need to copy the files to the hard drive of your computer or another location where you have write permission.  Each exercise has a listing of which files you will need to copy.  Files for exercises can be found in the gisfiles subdirectory of this module.

Resources on the Internet

Applications:

• Building a river database and using the ArcView application BALANCE to analyze point source pollution diffusion, Mark Graves
• CCBPARAM - Corpus Christi Bay Water Quality Model Parameter Estimation, Ferdi Hellweger

Related:

• CCBFLOW - A Steady State Hydrodynamic Model of Corpus Christi Bay

Primary Contact

Patrice A. Melancon
Center for Research in Water Resources
The University of Texas at Austin
Austin, TX 78712

Phone: (512) 471-0073
Fax: (512) 471-5870
E-mail: pmelancon@mail.utexas.edu
http://www.ce.utexas.edu/stu/melancpa

These materials may be used for study, research, and education, but please credit the authors and the Center for Research in Water Resources, The University of Texas at Austin. All commercial rights reserved. Copyright 1998 Center for Research in Water Resources.

  Return to the GIS Hydro'98 Homepage.