Development of Sediment and Nutrient Export Coefficients for US Ecoregions

作者：White Michael; Harmel Daren; Yen Haw; Arnold Jeff; Gambone Marilyn; Haney Richard

来源：Journal of the American Water Resources Association, 2015, 51(3): 758-775.

DOI：10.1111/jawr.12270

<jats:title>Abstract</jats:title><jats:p>Water quality impairment due to excessive nutrients and sediment is a major problem in the United States (<jats:styled-content style="fixed-case">U.S.</jats:styled-content>). An important step in the mitigation of impairment in any given water body is determination of pollutant sources and amount. The sheer number of impaired waters and limited resources makes simplistic load estimation methods such as export coefficient (EC) methods attractive. Unfortunately ECs are typically based on small watershed monitoring data, which are very limited and/or often based on data collected from distant watersheds with drastically different conditions. In this research, we seek to improve the accuracy of these nutrient export estimation methods by developing a national database of localized EC for each ecoregion in the <jats:styled-content style="fixed-case">U.S.</jats:styled-content> A stochastic sampling methodology loosely based on the Monte‐Carlo technique was used to construct a database of 45 million Soil and Water Assessment Tool (<jats:styled-content style="fixed-case">SWAT</jats:styled-content>) simulations. These simulations consider a variety of climate, topography, soils, weather, land use, management, and conservation implementation conditions. <jats:styled-content style="fixed-case">SWAT</jats:styled-content> model simulations were successfully validated with edge‐of‐field monitoring data. Simulated nutrient ECs compared favorably with previously published studies. These ECs may be used to rapidly estimate nutrient loading for any small catchment in the <jats:styled-content style="fixed-case">U.S.</jats:styled-content> provided the location, area, and land‐use distribution are known.</jats:p>

• 出版日期2015-6