Land Cover and Soil Properties of the San Marcos Basin

Cody McCann

Agenda

1. Study Area

2. NDVI and SAVI

3. Future Endeavors

The Good Ol’ San Marcos Subbasin

Raw Landsat Data

Normal Imagery: Red, Green, and Blue Composite Bands

Thermal Imagery DN: 8-bit, ranging from 0-255

NDVI and SAVI Progress Diagram

Correct Reflectance Data

Landsat 5 TM to Landsat 7 ETM+

Calculate the Radiance from Landsat 7

RadianceConversion Reflectance

Convert the Radiance into Reflectance

Correction

NDVI

NDVIValue

High : 1

Low : 0.172294

±

0 20 40 60 8010Miles

Doesn't really tell us much . . .

Why SAVI?

Soil-Adjusted Vegetation Index

Best used when:

• Low Vegetative Cover• Different Soil Types

Modification of NDVI

SAVI of the Subbasin

±0 20 40 60 8010

Miles

Much Better!SAVIValue

High : 0.220689

Low : 0

Direct Relation to Water

Direct Relation to Water

Relation to the Edwards Aquifer

Relation to the Edwards Aquifer

Future Endeavors

• Soil Brightness

• Soil and Land Cover

• Soil and Stream Network

Questions?

Thanks!

Dr. Maidment and Dr. Kilic