Heterogeneity of groundwater and surface water nitrate loads in nested urban watersheds
Abstract
Nitrogen export from urbanized watersheds is a major contributor to water quality degradation and eutrophication in receiving waters. Yet, many water quality models predict nitrate loads based on assumed inputs from land use and land cover classifications. We have evaluated three years of high frequency nitrate data from six nested stations within Dead Run, a 14.2 sq km watershed in suburban Baltimore, MD. We find that nitrate export does not vary monotonically with either drainage area or streamflow. While base flow accounts for 22 to 34 percent of the total annual discharge across these catchments, baseflow nitrate concentrations are higher than stormflow concentrations, resulting in base flow nitrate loads ranging from 13 to 49 percent of the total nitrate export on an annual basis. Better understanding of hot spots and hot moments of nitrate fluxes across spatial scales of urban watersheds can lead to more efficient water quality management.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H41Q2373D
- Keywords:
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- 0493 Urban systems;
- BIOGEOSCIENCESDE: 1847 Modeling;
- HYDROLOGYDE: 1878 Water/energy interactions;
- HYDROLOGYDE: 1880 Water management;
- HYDROLOGY