KELLY HAYDEN

Applying GIS to Watershed Pollution Management

CAN GIS TECHNOLOGY BE USED TO SOLVE

POLLUTION PROBLEMS?

Purpose

Background

GIS - Geographical Information systems

Visually represents data using layers

Low cost of operationBecoming widely

used

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GIS vs. Other Data Storage

GIS has a large databaseOrganizes data by any attributePerform queriesCreates layers from dataCan see spatial relationships over timeUses models to go beyond original data

Non-point source pollution

Fertilizers

Animals

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USING GIS-BASED HYDROGEOLOGIC MODELS

Solving Pollution Problems

Hydrogeologic Models

Input dataProcesses the informationOutputs data for interpretationApplication of GIS

Prepare input data Retains spatial relations of data Outputs visual representation Easy to interpret the output

Flow Models

Models create flow maps Where water is and how it flows

Groundwater time travel model Velocity of water Residence time

SWAT - Soil and Water Assessment Tool Effectiveness of existing pollution management

Flow Models

Input data Land use from remote

sensing Topography Soil properties Digital elevation

models Estimate hydraulic

conductivity and gradient

Depth to watertable

Digital Elevation Model

Pandey et al, 2008

Leh and Chaubey, 2009

Soil properties layer

Flow Maps

Uses Delineate watershed Locating source of

pollution Water quality sampling

sites Effects of management

plans current and future

Create better management plans

Flow map from groundwater time travel model showing residence

time

Schilling and Wolter, 2007

Vulnerability Maps

Output is a mapRanks watershed areas by risk for

contaminationDRASTIC and EPIC models

Weigh input data by their influence

Vulnerability Map

Input data Land use Depth to water table Hydraulic conductivity Soil properties

Mohammadi et. al., 2009

Vulnerability Map

Neural Network Model

Complicated mathematical modelMimics neurons in the brain

Identifies complex patternsWeighs input data and their relationsPredict pollutant concentrationsGIS used to prepare input-output vectorsGIS divides watershed into homogeneous

zones

Neural Network

Input data Land use Soil permeability Hydraulic conductivity

Neural Network Models

Classify areas by pollutant concentrationSpatial data displayed by GISPredictions are 74 % accurateUseful model because of small amount of

input dataLow cost compared to widely used transport

models

Limitations of GIS-based Hydrogeologic Models

Error from input data Outdated information Unavailable data Estimated parameters

Reduce error with field researchIncreases cost and timeError will lessen with time

Summary

GIS is an effective means of solving pollution problemsGIS can be used to run hydrogeologic modelsOrganizes dataCreates easy to interpret mapsAides management planning Can determine the effectiveness of management plansAccurate resultsLow costCan make pollution management easier and more

widespread

Questions?