Groundwater modeling using GIS technology Jessie Ackerman

Introduction • Groundwater is an important freshwater resource • Groundwater is held in aquifers • Studying groundwater is difficult because it’s underground • Groundwater modeling was developed to understand what’s going on • Modeling has developed as new technologies have developed

Purpose • Understand how GIS is used in groundwater modeling • Analyze current material on topic • Decide if GIS is useful in modeling groundwater

Basics of groundwater • • • Darcy’s Law Q = - K sat *A*d

h

/d

x

Understanding of flow Modeling developed first from an understanding of Darcy ’ s Law

Groundwater modeling • Field data including hydrological inputs, hydraulic parameters and initial and boundary conditions are gathered • Data input into modeling software • Models can be 1-D, 2-D, semi 3-D and 3-D

1-D model

2-D model

Semi 3-D model

Integrating GIS in models • GIS is a true 3-D model • Hydrologists looked to GIS to demonstrate erosion, sediment transport, and chemical transport simulations • Needed a program that could handle lots of data • Need to connect globally

Basics of GIS • A computer system designed to process information with a spatial content dimension • Composed of a geographical database and a toolkit

Modeling with GIS

Example using GIS technology • Searching for suitable area to tap aquifer near a landfill or other area of possible contamination • Landfill data and aquifer data input into GIS model • Program runs all possible situations

Work being done now using GIS technology • Recharge and discharge rates of aquifers • Used to make important decisions about water management • Illinois State Water Survey and University of Illinois

Buena Vista Ground Water Basin, Wisconsin

Analysis of resources • All but one source spoke well of using GIS within groundwater modeling • One source just tells hydrologists to be wary in using only GIS software to model groundwater

Conclusions • Gained an understanding of how GIS is used in groundwater modeling • GIS is very useful in creating 3-D models that incorporate lots of data • The best way to know if any advanced model is right is to go through it the long way first than to take shortcuts