AgroEcoSystem-Watershed (AgES-W) is a modular, Java-based, spatially distributed hydrologic/water quality (H/WQ) model that implements hydrological processes as encapsulated process-based modeling components running under the Object Modeling System 3 (OMS3) environmental modeling framework. The hydrological part of AgES-W (previously described in Ascough et al. 2012) consists of modeling components for interception, snow accumulation and ablation, horizontal-differentiated soil water balance, groundwater balance, runoff generation, and explicitly computed lateral surface and subsurface flows including flood routing in the watershed stream network. The nutrient transport modules evaluated in this study were adopted primarily from SWAT, converted to Java, and further modified for coupling to the AgES-W hydrologic components under OMS3. The nutrient modules include components for simulating soil temperature, crop growth, and nitrogen (N) turnover with some adaptations. Five different soil N pools are considered in order to allow modeling of different N inputs (e.g., inorganic fertilizer, organic manure, etc.) and N transformations between these pools. N reduction is modeled by a dynamic crop growth module (adapted from the SWAT and WEPP models) and subsequent N uptake by plants (residues and yield) as well as through N denitrification and volatilization. The influence of soil temperature and soil moisture on crop growth and N transformation are modeled synchronously. The AgES-W model estimates soil erosion and sediment yield from landscape hydrologic response units (HRUs) and from in-stream depositional and degradation processes. The HRU sediment yield is calculated by the Modified Universal Soil Loss Equation (MUSLE). Sediment deposition and degradation in stream channels are also calculated during sediment routing where the maximum amount of sediment that can be transported from a reach segment is governed by a modified Bagnold’s equation. All AgES-W modules currently operate on a daily time step. AgES-W employs a unique topological routing scheme (thus allowing simulation of lateral processes important for the modeling of runoff and chemical concentration dynamics) which is more robust than the quasi-distributed routing schemes used by other watershed-scale natural resource models (e.g., SWAT). With a fully distributed routing concept, higher spatial resolution in combination with the lateral transfer of water and chemicals between HRUs and stream channel reaches should result in improved H/WQ modeling for mixed-use watersheds. For additional information on AgES-W, please contact Dr. Jim Ascough at 970-492-7371 (e-mail: email@example.com).
Operating System: Windows XP/Vista/7/8
Software: Java 1.6/1.7 (NetBeans IDE Vers. 7.3 and OMS 3 to compile)
Hardware: 300 MB free disk space