CS 128/ES Lecture 13a1 Spatial Analysis – A Case Study

CS 128/ES Lecture 13a2 Problem Landslides are present in certain areas of West Virginia Question: How much of a determinant is land slope in this matter?

CS 128/ES Lecture 13a3 Where to begin? West Virginia Landslide and Slide Prone Areas map Paper only so scanned in

CS 128/ES Lecture 13a4 What to add? DEMs available at different resolutions 10 meter and 30 meter resolution DEMs imported Also a Geology map and a DOQQ

CS 128/ES Lecture 13a5 Adding relevant data Landslide polygons added through “heads up” digitization Attribute table used for determining area of slides

CS 128/ES Lecture 13a6 Hypothesis Slope has something to do with the prevelance of landslides Literature suggests that 35 degrees is a critical value

CS 128/ES Lecture 13a7 Getting Slope Information ArcMap’s Spatial Analysis was applied to DEMs Slope shown by color – degree values in Table of Contents

CS 128/ES Lecture 13a8 30 meter resolution

CS 128/ES Lecture 13a9 10 meter resolution

CS 128/ES Lecture 13a10 More interesting analysis Intersecting slope map with slide polygons layer allows us to determine average slope of a slide Determined to be degrees

CS 128/ES Lecture 13a11 Further filtering – 10 m

CS 128/ES Lecture 13a12 Further filtering – 30 m

CS 128/ES Lecture 13a13 Final product What layers should be included? How should they be arranged?

CS 128/ES Lecture 13a14 A Useful Map?

CS 128/ES Lecture 13a15 Intriguing Questions Why doesn’t 30 m map do “better”? What role does geology play? What about soil type?

CS 128/ES Lecture 13a16 BIBLIOGRAPHY All figures (and details about the study) were taken from: 591/fall2001/students/kish/The%20Use%20of%2010%20Meter%20and% 2030%20Meter%20Digital%20Elevation%20Models%20for%20Determinin g%20Areas%20Susceptible%20to%20Landsliding%20in%20the%20Morga ntown%20N.htm 591/fall2001/students/kish/The%20Use%20of%2010%20Meter%20and% 2030%20Meter%20Digital%20Elevation%20Models%20for%20Determinin g%20Areas%20Susceptible%20to%20Landsliding%20in%20the%20Morga ntown%20N.htm Better approach – go to 591/ and explore projects (This one from Fall 2001 – Patrick Kish) 591/