A refined regional modeling approach for the Corn Belt – Experiences and recommendations for large-scale integrated modeling

摘要: Summary Nonpoint source pollution from agriculture is the main of nitrogen and phosphorus in stream systems Corn Belt region Midwestern US. This comprised two large river basins, intensely row-cropped Upper Mississippi River Basin (UMRB) Ohio-Tennessee (OTRB), which are considered key contributing areas for Northern Gulf Mexico hypoxic zone according to US Environmental Protection Agency. Thus, this area it utmost importance ensure that intensive food, feed biofuel production can coexist with a healthy water environment. To address these objectives within basin management context, an integrated modeling system has been constructed hydrologic Soil Water Assessment Tool (SWAT) model, capable estimating responses alternative cropping and/or strategies. improve performance compared previous studies provide spatially detailed basis scenario development, SWAT application incorporates greatly refined subwatershed structure based on 12-digit units or ‘subwatersheds’ as defined by Geological Service. The model setup, calibration validation time-demanding challenging tasks systems, given scale data requirements, need reliability flow pollutant load predictions at multiple locations. study both comprehensively describe large-scale approach, providing estimates crop well present strengths weaknesses such along how be improved current results. were semi-automatic approach studies, use Sequential Uncertainty Fitting algorithm (SUFI-2) SWAT-CUP interface, followed manual quality monthly basis. developed led successful across most parts used testing mitigation measures agricultural economic scenarios, useful information policy makers recommendations similar efforts regional scale.