Impact of bioenergy policy induced land use change on water quality under changing climate in the Northern Great Plains of the USA

摘要

Lake Ashtabula, located in the Northern Great Plains of the USA, has been listed as a nutrients-impaired water body by the United States Environmental Protection Agency with high priority to develop total maximum daily load (TMDL) reduction plans. The watershed draining into the lake is predominantly of agricultural land uses, which have changed considerably in recent years due to bioenergy policies. The region has also been experiencing a decade-long abnormally wet weather pattern since the early 1990s. A Soil and Water Assessment Tool model for Lake Ashtabula watershed was developed and calibrated to estimate annual sediment and nutrient loads into Lake Ashtabula under different land use and climate scenarios. The model could be used further for developing sediment and nutrient TMDLs for Lake Ashtabula and for identifying contributing areas targeted for watershed management and lake water quality improvement.