You are here:
An Integrated Multi-Media Modeling System for Regional to National-scale Ecosystem Assessments
Citation:
Yuan, Y., L. Ran, S. Wang, V. Benson, AND Y. Wan. An Integrated Multi-Media Modeling System for Regional to National-scale Ecosystem Assessments. AGU, Chicago, IL, December 12 - 16, 2022.
Impact/Purpose:
Water bodies and coastal areas around the world are threatened by excessive amounts of nitrogen (N) and phosphorous (P) from upstream watersheds, which can cause rapid proliferation of algae. These algal blooms negatively impact drinking water sources, aquatic species, and recreational services of water bodies by producing toxins, also called harmful algal blooms (HABs). Finding ways reducing nutrient losses from agricultural fields is paramount important for EPA program offices and regional partners to make informed decisions to better control nutrient losses from agricultural fields.
Description:
This study describes an integrated multi-media modeling system (IMMMS) that includes the following components: (1) Community Multiscale Air Quality (CMAQ), (2) Weather Research and Forecasting Model (WRF), (3) Environmental Policy Integrated Climate (EPIC), and (4) Soil and Water Assessment Tool (SWAT). An advanced Java-based user interface has been developed to prepare inputs, integrate EPIC with the WRF and CMAQ as well as SWAT with EPIC, both driven by the process-based WRF weather simulations, and output processing. The integration of EPIC with WRF and CMAQ includes atmospheric N additions to agricultural cropland and agricultural cropland contributions to ammonia emissions, which allows bidirectional NH3 flux between air and agricultural land. The integration of SWAT with EPIC allows a full multimedia assessment on water quality in large river basins to address impacts of fertilization, meteorology, and atmospheric N deposition on water quality. The IMMMS (SWAT/EPIC/WRF/CMAQ) simulates daily fertilizer application to agricultural lands for bi-directional ammonia (NH3) modeling in the CMAQ model and is useful for assessing impacts of agricultural fertilization and management practices not only on air quality (NH3) and climate (nitrous oxide (N2O)), but also on crop yield, soil erosion, and water quality. For integrated modeling demonstration and evaluation, the system was used to simulate three individual years with WRF/CMAQ weather and N deposition. Simulated annual changes for two major crops (corn grain and soybean) match those inferred from intuitive physical reasoning and survey data given different-year weather conditions. In addition, application of the system to the Mississippi River basin (MRB) to simulate streamflow and dissolved N loadings to the Gulf of Mexico (GOM) showed that the simulation results generally agree with US Geological Survey (USGS) observations/estimations. With new technology and new data available, the system needs to be continuously enhanced to allow for flexible incorporation of input data such as land use data and spatial representation of agricultural management practices. This presentation also demonstrates the newly developed fertilizer management scenarios and its impact on crop yields. Finally. limitations and issues in different parts of the integrated multimedia simulations are identified and discussed to target areas for future improvements.
