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EGSC WaterSMART-irrigation water use research Input for the ACF WaterSMART Stakeholders meeting John W. Jones USGS Eastern Geographic Science Center March 08, 2012
How much (which) land is irrigated? • Create maps of water evaporation from satellite imagery. • Irrigated land = high demand and high evaporation and cropland. • Test map accuracy through comparison with GaMP data and irrigation demand analysis.
How much water is evaporating in irrigated areas? • Create maps of water evaporation from satellite imagery. • Interpolate instantaneous evaporation between image dates. • Sum evaporation by location. • Compare against GaMP, ground-based evaporation measurements and hydrologic model estimates.
Evaporation example from AR / MS pilots • Mississippi County AR Goal: apportion ground measured annual total irrigation to growing season dates. • Yazoo delta MS Goal: Extrapolate limited monitoring data to entire region and longer time frames.
Remote sensing approach uses satellite based surface temperature • Surface temperature on June 26, 2009. • Mississippi County, Arkansas outline shown in black.
Remote sensing approach uses satellite based estimates of vegetation amount • Vegetation Index (NDVI) for June 26, 2009. • Mississippi County, Arkansas outline shown in black.
Vegetation amount (NDVI) vs. temperature of the surface (Ts) – temperature of the air (Ta) • A – HIGH Evapotranspiration (little difference between surface and air temperature) • B – low Evapotranspiration (large temperature difference over dense vegetation) • C – HIGH soil Evaporation (small temperature difference over bare ground) • D – low soil Evaporation (large temperature difference over bare ground)
June 21 2009 evapotranspiration • Mississippi County, Arkansas boundary shown in black.
Progress to-date • Specific GA study area selected (Spring and Ichawaynochaway Creeks) • Landsat imagery selected, acquired and calibrated to at-surface reflectance. • Two major components of analysis have been coded for batch processing. • Challenge: Discovered cloud/cloud shadow screening “glitch” is being corrected.
Progress to-date • Image database (to-date):