Assessment of Statewide Remote Sensing-Based Evapotranspiration Estimates

Estimates of actual evapotranspiration (ET) using remote sensing methods can be used in wide range of hydrological and water resources applications including water resources management at river basin scales, drought monitoring, drought impact and socioeconomic responses, agricultural water management, land-use management and water conservations. As each application requires different spatial and temporal time scales, there is a need to identify appropriate type of ET information that can address each application. For example, drought monitoring and drought impact analysis can adequately be addressed using ET information in the order of few kilometers and biweekly time scales while agricultural water management applications require ET information at field (30-m) and daily time scales. This analysis will evaluate the potential of using ET information based on an integrated approach to collectively and appropriately be used to address some of these issues. This analysis will highlight the use of this approach to address some of the needs for New Mexico including assessment of statewide water budget as well as drought impact and socioeconomic responses. Four remote sensing-based ET models including ALEXI, DisALEXI, SSEBop, and SEBAL3.0 to provide estimates of actual ET at 30 m – 4 km and daily – weekly time scales using data from Landsat, MODIS, and VIIRS sensors. Estimates of ET will be compared with ground-based observations from eddy covariance towers and water balance calculations.