Impact of climate change on diffuse pollutant fluxes at the watershed scale

摘要: This study aims to assess watershed-scale impacts of changing climate on sediment, phosphorus, nitrogen and pesticide (atrazine) fluxes over the 21st century at watershed scale. In particular, changes in dissolved particulate forms water quality constituents response change are investigated. The hydrologic model Soil Water Assessment Tool was calibrated evaluated a primarily agricultural Midwestern United States simulate processes daily basis 2015–2099 time horizon. then driven with 112 distinct statistically downscaled projections representing Intergovernmental Panel Climate Change Special Report Emissions Scenarios (IPCC SRES) low, moderate high greenhouse gas emission scenarios. Projected responses were categorized according three IPCC SRES scenarios for summarizing synthesizing results early-century (2015–2034), mid-century (2045–2064) late-century (2080–2099) assessment. Results revealed clear warming trends area, whereas small increases precipitation predicted. Streamflow, sediment total nutrient loads did not differ noticeably between assessment periods. However, proportion nutrients increased significantly from With exception atrazine period, predicted pollutant given period pathways period. Changes showed pronounced monthly variability. projected increase readily available has important implications ecological health systems management drinking supplies. Copyright © 2013 John Wiley & Sons, Ltd.