Three Year Drought Analysis A Tasseled Cap Transformation Folsom Lake, CA Joseph Watkins GEOG 342 Final Project

 Perform a Tasseled Cap Transformation on the Sacramento River and American river independently, over a three year period to determine if the current drought had an equitable impact. Initial Idea – Two Rivers Analysis

 was used to find Landsat-8 imagery of Sacramento county.  Image parameters consisted of:  Place: Sacramento, CA.  Date: July 20 th – July 31 st 2013, 2014, and  Data Set: Landsat-8 OLI (Operational Land Imager) and TIRS (Thermal Infrared Sensor).  Additional Criteria: Cloud Cover less than 20%, and Day indicator.  This resulted in 7.5 gigabytes of imagery. Initial Idea – Two Rivers Analysis

Footprint too small!

 SJWD water source as stated by “Your water flows straight from the pristine American River watershed to Folsom Lake. “ New Project Overview – Drought Impact on Folsom Lake and water use in the San Juan Water District

 File archiver needed to extract.tar.gz files to view USGS Landsat-8 images. Specs – 7-Zip

 Search for Landsat-8 TC coefficients.  Forum used from gis.stackexchange.com and confirmed through ESRI. Specs – Acquire TC coefficients

 Path, Reference, Bands, and Coefficients. Specs – Tasseled Cap Script Mod

 Perform a heads-up digitization of Folsom Lake using the Draw tool to create a manageable subset image.  Import additional images and repeat subset process. Method – Folsom Lake Subset

 Determine the SJWD boundary.  Create a subset image of SJWD sample area using the same method as Folsom Lake.  Import additional images and repeat subset process. Method – SJWD Subset

 The Tasseled Cap program revealed image Brightness, Greenness, and Wetness for each image. Transformation

 Reference each image Histogram to derive the mean figures. Transformation

 Excel charts were created to compare SJWD water use to the receding water line of Folsom Lake. Analysis

 IT WORKS!  Effectively tells a story about the image  Easy to use  Runs in under a minute  Handles large amounts of data  Engages the analyst in creative potential Conclusion

 Folsom Lake footprint saw a 48% reduction of wetness over the 3 year analysis.  SJWD sampling saw a 16% reduction in wetness.  More factors would need to taken into account.  Consumption of other water districts.  Water release for farming & salmon spawning.  Authorized watering day vs. image date.  Conservation efforts are working. Conclusion