Abstract

Method to compare maps that show a direction variable
Track: Modeling
Author(s): Rahul Rakshit, Robert Pontius

Maps that show a direction variable such as aspect are essential in various spatial analyses such as flow direction, solar insolation, viewshed analysis and wind potential modeling. Therefore it is essential to have quantitative methods to analyze such maps in a manner that appreciates these distinctive attributes. This paper's objective is to demonstrate a novel method of comparing and quantifying the difference between two directional maps. The proposed technique is illustrated by comparing two aspect maps that are derived from the same elevation map but different GIS algorithms one using ArcGIS and the other using Idrisi. A tool is then created in the ArcGIS model maker to answer the following questions:

1. What is an appropriate way to measure the difference between two maps that show a directional variable?

2. How is the measure of the difference influenced by scale?

Rahul Rakshit
Clark University
950 Main St
Dept of Geography
Worcester , Massachusetts 01610
United States
Phone: 5082468654
E-mail: rrakshit@clarku.edu

Robert Pontius
Clark University
950 Main St
Dept of Geography
Worcester , Massachusetts 01610
United States
Phone: 508) 793-7761
E-mail: rpontius@clarku.edu