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United States Department of Agriculture

Agricultural Research Service

Research Project: OBJECT MODELING AND SCALING OF LANDSCAPE PROCESSES AND CONSERVATION EFFECTS IN AGRICULTURAL SYSTEMS

Location: Agricultural Systems Research Unit

Title: Evaluation of the Agro-EcoSystem-Watershed (AgES-W)model for estimating nutrient dynamics on a midwest agricultural watershed

Authors
item Ascough, James
item David, Olaf -
item Smith, Douglas
item Heathman, Gary

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 7, 2011
Publication Date: July 18, 2011
Citation: Ascough II, J.C., David, O., Smith, D.R., Heathman, G.C. 2011. Evaluation of the Agro-EcoSystem-Watershed (AgES-W)model for estimating nutrient dynamics on a midwest agricultural watershed. Soil and Water Conservation Society Annual Meeting,July 17-20,2011, Washington, D.C. Paper No. CTT-2.

Interpretive Summary: A new watershed model development approach has been initiated to: 1) disaggregate various agroecosystem models (e.g., J2K-S, SWAT, WEPP) and implement hydrological, N dynamics, and crop growth science components; 2) assemble a new modular watershed scale model for fully-distributed transfer of water and N loading between land units and stream channels; and 3) evaluate the accuracy and applicability of the modular watershed model for estimating stream flow and N dynamics. The Cedar Creek watershed (CCW) in northeastern Indiana, USA was selected for application of the new AgroEcoSystem-Watershed (AgES-W) model. AgES-W performance for stream flow and N loading was assessed using Nash-Sutcliffe model efficiency (ENS) and percent bias (PBIAS) model evaluation statistics. Comparisons of daily and average monthly simulated and observed stream flow and N loads for different simulation periods resulted in PBIAS and ENS values that were similar or better than those reported in the literature (for other watershed models at a similar scale). The results show that the AgES-W model was able to reproduce the hydrological and N dynamics of the CCW with sufficient quality, and should serve as a foundation upon which to better quantify additional water quality indicators (e.g., sediment transport and P dynamics) at the watershed scale.

Technical Abstract: In order to satisfy the requirements of Conservation Effects Assessment Project (CEAP) Watershed Assessment Study (WAS) Objective 5 (“develop and verify regional watershed models that quantify environmental outcomes of conservation practices in major agricultural regions”), a new watershed model development approach was initiated. Specific model development objectives were to: 1) disaggregate and refactor various agroecosystem models (e.g., J2K-S, SWAT, WEPP) and implement hydrological, N dynamics, and crop growth science components; 2) assemble a new modular watershed scale model for fully-distributed transfer of water and N loading between land units and stream channels; and 3) evaluate the accuracy and applicability of the modular watershed model for estimating stream flow and N dynamics. The Cedar Creek watershed (CCW) in northeastern Indiana, USA was selected for application of the new AgroEcoSystem-Watershed (AgES-W) model. AgES-W performance for stream flow and N loading was assessed using Nash-Sutcliffe model efficiency (ENS) and percent bias (PBIAS) model evaluation statistics. Comparisons of daily and average monthly simulated and observed stream flow and N loads for different simulation periods resulted in PBIAS and ENS values that were similar or better than those reported in the literature (for other watershed models at a similar scale). The results show that the AgES-W model was able to reproduce the hydrological and N dynamics of the CCW with sufficient quality, and should serve as a foundation upon which to better quantify additional water quality indicators (e.g., sediment transport and P dynamics) at the watershed scale.

Last Modified: 4/20/2014
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