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Remote sensing –Beyond images Mexico 14-15 December 2013 The workshop was organized by CIMMYT Global Conservation Agriculture Program (GCAP) and funded by the Bill & Melinda Gates Foundation (BMGF), the Mexican Secretariat of Agriculture, Livestock, Rural Development, Fisheries and Food (SAGARPA), the International Maize and Wheat Improvement Center (CIMMYT), CGIAR Research Program on Maize, the Cereal System Initiative for South Asia (CSISA) and the Sustainable Modernization of the Traditional Agriculture (MasAgro)
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Daily evapotranspiration by combining remote sensing with ground
observations: Study from Maricopa, Arizona USA
Andy French and Doug [email protected]
U.S. Arid Land Agricultural Research Center, USDA/ARS, Maricopa, AZ USA
Obtaining Daily ET Estimates Useful for Growers
•Remote sensing provides synoptic views and ways to model instantaneous ET•Obstacles;• Image data too infrequent• Or too coarse• Costly
•Combine remote sensing data with ground observations• Obtain image data as available• Continuous monitoring of meteorology and land surface temperatures• Model spatial LST and vegetation cover • Compute surface energy balance hourly, integrate to daily
Penman-Monteith Equation
DiabaticFlux
AdiabaticFlux
Energy Flux Equations
Surface Flux Modeling Remote Sensing Inputs
NDVI
Temperature
Surface Energy Balance ASTER El Reno, Oklahoma
4 Sep 2000
SensibleHeat
LatentHeat
Daily Evapotranspiration4 Sep 2000
90 m
91 m
64%
4%
FAO Irrigation Scheduling Experiment SiteMaricopa, Arizona
Integrated Monitoring of Crop and Irrigation
Wireless-Based Sensors for Water Management
Maricopa Irrigation Scheduling Experiment 2003Cotton
Simplifying LST to Assist Daily Forecast of ET
Heat Units and Kalman Filtering to Forecast Spatially Distributed Cover & LST
Need Mean & SD Cover Estimates
Daily ET Modeling & Accuracy Assessment
Use parameter uncertainties to model ET uncertaintyCompare ET estimates against P-M and soil moisture
Remote Sensing Resolution and Local Vegetation/Soil Scales
Thermal Imaging & ET: Some Variations Irrelevant for Daily Estimates
Winter Wheat Grazingland
NDVI NDVI
Emissivity
Newer Remote Sensing CapabilitiesMultispectral Thermal Infrared
Emissivity Change at Palo Verde Irrigation District 2007-8
Conclusions
•Combined Remote Sensing & Ground-Based Sensors •Daily ET for Water Management•Reasonable resolution & forecast potential•Reasonable Cost•New satellite sensors will improve ET estimation accuracies•Uncertainty estimation important part of advisory system
