Updated Estimation of Annual Phreatophytic Evapotranspiration for White River, Spring, and Snake Valleys

Affiliation(s)PIProject periodFunded by
DEES Fenstermaker, Lynn 07/01/2010 - 10/31/2011 Southern Nevada Water Authority

Project Description

The Southern Nevada Water Authority (SNWA), Desert Research Institute (DRI) and University of Nevada Las Vegas (UNLV) have collected evapotranspiration (ET) data within White River, Spring, and Snake valleys from 2005 to present. ET data collected during the period 2005 through 2007 in all three valleys were reported by Devitt et al. (2008) and for Spring Valley in 2007 by Arnone et al. (2008). Since 2008, DRI has further refined the methodology for deriving basin-scale ET estimates using a weighted Normalized Difference Vegetation Index (NDVI) footprint approach. The primary purpose of the current project is to update the basin-scale ET estimates for White River, Spring, and Snake valleys. The updated estimates will be based on remotely-sensed satellite imagery processed by DRI and measured ET rates at the DRI, UNLV, and SNWA ET sites for the years 2006 through 2010. A regression analysis will be performed using these data to derive a relationship between annual total ET and weighted average NDVI values that will be used to estimate basin-scale total annual ET. A subset of the measured ET data will be reserved to perform an accuracy assessment.