Sensing the Non-mainStream in Los Angeles

Earthzine2015 Spring VPS, DEVELOP Virtual Poster Session, Managing Water Resources and Restoration

Category: Managing Water Resources and Restoration

Project Team: Los Angeles Water Resources

Team Location: NASA Jet Propulsion Laboratory ‰ÛÒ Pasadena, California

Red, blue, green composite image of horizontal horizontal (HH), vertical vertical (VV) and horizontal vertical (HV) polarizations within the San Gabriel Watershed. Red highlights urban/soil, green highlights vegetation and blue/black highlights water. Image Credit: Los Angeles Water Resources Team


Gwen Miller

Rosemarie Wrigley

Montana Marshall

Claudia Knudson


Cedric David (NASA Jet Propulsion Laboratory)


Resource agencies such as the Council for Watershed Health (CWH) and the Southern California Coastal Water Research Project (SCCWRP) rely on accurate knowledge of the entire watershed system to monitor, model and manage water resources. The current methods to detect streams and predict flow regimes (perennial/intermittent) in California’s watersheds mostly use field measurements. Intermittent stream identification is challenging using these methods, and field verification is labor intensive and expensive. To assess the feasibility of using remote sensing, we determined which NASA sensors were compatible for our study and then researched, created and executed methodologies to analyze Landsat and UAVSAR data. We used Landsat 5 TM and Landsat 8 OLI to analyze the potential of imagery to detect surface water, soil moisture and vegetation-rich areas by performing band combinations, band math, classification and change detection. We used UAVSAR (PolSAR) to evaluate the potential of radar to detect soil moisture and vegetation by using different band polarizations, performing land classification, and change detection. Our findings indicate that UAVSAR data and Landsat data cannot effectively locate small intermittent streams, but can be useful in analyzing trends within larger water bodies such as reservoirs. Our results are useful to the CWH and the SCCWRP in understanding the potential use of Earth observation data for enhanced decision-making.

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