Location: Water Management and Systems Research2017 Annual Report
1a. Objectives (from AD-416):
Objective 1: Quantify changes in agricultural production and fluxes of water and associated nutrients (N and P) and sediment from field to watershed scales over the next several decades at fine temporal resolutions in response to changes in water availability, land use, management practices, and climate. Sub-objective 1.1. Understand and quantify the effects of variable irrigation practices on crop production responses by assessing genotype x environment x limited-water management (GEM) interactions for different land use, management, and climate scenarios at field to watershed scales. Sub-objective 1.2. Improve estimates of water redistribution and storage by resolving spatial scale issues related to the measurement and simulation of soil moisture in cropland and grassland ecosystems at field to watershed scales. Simulate hydroecology within the SPRB and the Central Plains Experimental Range (CPER) Long-Term Agroecosystem Research (LTAR) site to extend experimental results to larger areas and different management scenarios. Sub-objective 1.3. Understand how the effectiveness of spatially distributed water conservation strategies and agricultural best management practices (BMPs) for nutrient and sediment control vary with landscape position, geographic/geologic characteristics of the field, farm, or watershed, and other factors. Objective 2: Assess key ecosystem services for projected water requirements and water quality targets in the South Platte River Basin, Colorado, at field to watershed scales in response to changes in water availability, land use, management, and climate. Objective 3: Develop and disseminate a web-based geospatial data management system as a repository of data, models, and tools for accelerating collaborative research and facilitating sustainable management of water, nutrients, and sediment.
1b. Approach (from AD-416):
Objectives 1 and 2 focus on enhancing scientific knowledge for incorporation into the Agricultural Ecosystems Services (AgES) distributed watershed model with subsequent testing and application of AgES. Objective 1 is divided into three sub-objectives integrated from smaller to larger scales, which focus on: (1.1) improved model components for plant modeling of GEM interactions, particularly for irrigated water management, (1.2) soil water modeling emphasizing spatial scaling of soil water and surface runoff in dryland cropping and rangeland systems, and (1.3) simulation of conservation effects over regional watersheds, primarily in Iowa where collaborators have been investigating and monitoring water quality impacts over decadal time scales. In Objective 2, the AgES model will be used to simulate a series of land use, management practice and climate scenarios for hydrologic and water quality ecosystem service indicators in eastern Colorado. Objective 3 involves development of a web-based Geospatial Portal for Scientific Research (GPSR) for technology transfer of geospatial information. GPSR will be used for dissemination of the results of the present project together with broader technology transfer by ARS and collaborators, such as experimental results generated from Long-Term Agricultural Research sites and Climate Hubs.
3. Progress Report:
Obj. 1.1: Development and testing of the Unified Plant Growth Model (UPGM) within the Agricultural Ecosystems Services (AgES) model continued, including 1) evaluating the model for phenological genetics-by-environment-by-management interactions with a manuscript being submitted in FY17, and 2) work is progressing in conjunction with the Wind Erosion Predictions System (WEPS) modeling team on restructuring and redesign of UPGM to create a plant growth component that can more readily incorporate more recent scientific concepts and approaches and replace the plant growth components of other agency models such as WEPS, WEPP, and SWAT. Obj. 1.2: Spatial “scaling” of soil water measurements up to the field/watershed and down to simulated areas has been studied using data from the Drake Farm in Colorado and the Agricultural Ecosystems Services (AgES) watershed model. AgES was developed by ARS researchers in Fort Collins, Colorado collaboratively with Researchers at Colorado State University. The scaling study includes effects of spatial resolution and parameter complexity on AgES model results. Overall Project Deliverable: The User Manual is being updated for the new version (2.0) of the Agricultural Ecosystems Services (AgES) watershed model. Updates include new file handling and science components, which make it a major update.