EGSC WaterSMART-irrigation water use research John W. Jones USGS Eastern Geographic Science Center March 08, 2012 Input for the ACF WaterSMART Stakeholders meeting

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.

 Mississippi County AR Goal: apportion ground measured annual total irrigation to growing season dates. Evaporation example from AR / MS pilots  Yazoo delta MS Goal: Extrapolate limited monitoring data to entire region and longer time frames.

 Surface temperature on June 26,  Mississippi County, Arkansas outline shown in black. Remote sensing approach uses satellite based surface temperature

 Vegetation Index (NDVI) for June 26,  Mississippi County, Arkansas outline shown in black. Remote sensing approach uses satellite based estimates of vegetation amount

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) Vegetation amount (NDVI) vs. temperature of the surface (Ts) – temperature of the air (Ta)

 Mississippi County, Arkansas boundary shown in black. June evapotranspiration

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): YearLandsat 5Landsat 7Total Total383977