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Updated: Jul 5, 2026
12:50
Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds
Published on: September 26, 2017
Baseflow nitrate in relation to stream order and agricultural land use
Shujiang Kang1, Henry Lin, William J Gburek
1Department of Crop and Soil Science, The Pennsylvania State University, University Park, PA 16802, USA.
Journal of Environmental Quality
|May 6, 2008
Summary
Agricultural nonpoint-source pollution management is challenging. This study found stream order can estimate nitrate levels and loads in agricultural watersheds, aiding water quality assessment.
Area of Science:
- Environmental Science
- Hydrology
- Agricultural Science
Background:
- Agricultural nonpoint-source pollution presents significant management challenges due to spatial and temporal variability.
- Understanding the distribution of pollutants like nitrate within stream networks is crucial for effective watershed management.
Purpose of the Study:
- To explore the distribution of nitrate concentration and load along stream networks in agricultural watersheds using stream order as an index.
- To investigate the impact of agricultural land use on baseflow nitrate concentration and load within these networks.
Main Methods:
- Focused on baseflow conditions to analyze groundwater contributions to stream nitrate.
- Utilized stream order as a framework to examine nitrate distribution across a hierarchical stream network.
- Conducted statistical analyses to determine relationships between agricultural land use and nitrate levels.
Main Results:
- Nitrate concentration generally decreased with increasing stream order, but showed significant spatial and temporal variability.
- Nitrate loads increased with stream order, following a power function driven by streamflow.
- Positive linear relationships were identified between agricultural land use percentage and baseflow nitrate concentration, and between agricultural drainage area and nitrate load.
Conclusions:
- Stream order serves as a useful index for estimating baseflow nitrate concentration and load distribution in agricultural watersheds.
- The relationship between agricultural land use and nitrate levels can indicate watershed health and inform management strategies.
- Stream order integrates pollution sources and transport, offering a simplified approach to assessing nonpoint-source pollution trends.
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