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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #353984

Research Project: Improving the Sustainability of Irrigated Farming Systems in Semi-Arid Regions

Location: Water Management and Systems Research

Title: Evapotranspiration in DSSAT: Using Global Sensitivity Analysis and Standardized Crop Coefficient Methods to Evaluate Model Sensitivity and Behavior

item DeJonge, Kendall
item Thorp, Kelly

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/25/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: There has recently been increased focus on evaluating evapotranspiration (ET) in crop models. This talk discusses two previously published studies using DSSAT models that contribute to the overall body of research in this topic. The first study used Global Sensitivity Analysis (GSA) procedures to evaluate model output sensitivity to various input parameters, primarily dealing with important outputs of yield and ET. The outcomes of this GSA can give guidance to systematic calibration procedures, as well as overall increased understanding of the connection between model inputs and outputs. The second study integrated DSSAT models with standardized ET methodologies (namely FAO-56 and ASCE Standardized Reference Methods), and effort which had not been fully implemented previously. By using this new ET module, we show that the model now has more reasonable functional behavior. Finally, we show how comparing ET values in the context of crop coefficients, and evaluating model behavior, can provide insight into model deficiencies that may not be possible just by comparing to observed data.