Integrating multimedia models to assess nitrogen losses from the Mississippi River basin to the Gulf of Mexico
Citation:
Yuan, Y., R. Wang, E. Cooter, L. Ran, P. Daggupati, D. Yang, R. Srinivasan, AND A. Jalowska. Integrating multimedia models to assess nitrogen losses from the Mississippi River basin to the Gulf of Mexico. Biogeosciences. Copernicus Publications, Katlenburg-Lindau, Germany, 15(23):7059-7076, (2018). https://doi.org/10.5194/bg-15-7059-2018
Impact/Purpose:
This study is intended to fill a research gap for integrated, multi-media modeling and transdisciplinary approaches to evaluate nitrogen fate and transport comprehensively in large river basins. The modeling system descript in this study includes: 1) Community Multi-Scale Air Quality (CMAQ); 2) Water Research and Forecasting (WRF); 3) Environmental Policy Integrated Climate (EPIC); and 4) Soil and Water Assessment Tool (SWAT). The previously developed Fertilizer Emission Scenario Tool for the Community Multiscale Air Quality (FEST-C) system integrated EPIC with the WRF model and CMAQ. FEST-C, driven by process-based WRF weather simulations,includes atmospheric N additions to agricultural cropland, and agricultural cropland contributions to ammonia emissions. Watershed hydrology and water quality models need to be integrated with the system, however, so it can be used in large river basins to address impacts of fertilization, meteorology, and atmospheric N deposition on water quality. We expanded the previous effort by integrating a watershed model with the FEST-C (CMAQ/WRF/EPIC) and demonstrated application of the Integrated Modelling System (IMS) to the Mississippi River Basin (MRB) to simulate dissolved N loadings to the Gulf of Mexico (GOM). Information on nitrogen loadings to the GOM is urgently needed by the Hypoxia Task Force (HTF), a collaborative effort of federal and state agencies including EPA, and tribes to investigate its impact on the size of the hypoxia zone of the GOM.
Description:
This study describes and implements an integrated, multimedia, process-based system-level approach to estimating nitrogen (N) fate and transport in large river basins. The modeling system includes: 1) Community Multi-Scale Air Quality (CMAQ); 2) Water Research and Forecasting (WRF); 3) Environmental Policy Integrated Climate (EPIC); and 4) Soil and Water Assessment Tool (SWAT). The previously developed Fertilizer Emission Scenario Tool for the Community Multiscale Air Quality (FEST-C) system integrated EPIC with the WRF model and CMAQ. FEST-C, driven by process-based WRF weather simulations, includes atmospheric N additions to agricultural cropland, and agricultural cropland contributions to ammonia emissions. Watershed hydrology and water quality models need to be integrated with the system, however, so it can be used in large river basins to address impacts of fertilization, meteorology, and atmospheric N deposition on water quality. Objectives of this paper are to describe how to expand the previous effort by integrating a watershed model with the FEST-C (CMAQ/WRF/EPIC) modeling system, as well as demonstrate application of the Integrated Modelling System (IMS) to the Mississippi River Basin (MRB) to simulate streamflow and dissolved N loadings to the Gulf of Mexico (GOM). Preliminary results are very promising compared to USGS streamflow observations and dissolved N estimations, particularly on dissolved N. Integrating SWAT with the CMAQ/WRF/EPIC modeling system allows its use with large river basins without losing EPIC’s more detailed biogeochemistry processes. The IMS can assess impact of climate change, Clear Air Act regulations, and land use and land management on N transport and transformation in large river basins.
URLs/Downloads:
DOI: Integrating multimedia models to assess nitrogen losses from the Mississippi River basin to the Gulf of Mexico