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Updated: May 10, 2026
05:04
Visualization of Productivity Zones Based on Nitrogen Mass Balance Model in Narragansett Bay, Rhode Island
Published on: July 14, 2023
Nitrate source apportionment in a subtropical watershed using Bayesian model.
Liping Yang1, Jiangpei Han, Jianlong Xue
1College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, People's Republic of China.
The Science of the Total Environment
|July 4, 2013
Summary
Nitrate pollution in subtropical watersheds varies seasonally, with atmospheric deposition and manure/sewage being key sources in the dry season, and synthetic fertilizers dominating in the wet season. Understanding these nitrate sources is crucial for water quality management.
Area of Science:
- Environmental Science
- Hydrology
- Biogeochemistry
Background:
- Nitrate (NO3-) pollution is a global environmental concern impacting aquatic ecosystems.
- Understanding the temporal dynamics and sources of nitrate is vital for effective water quality management.
Purpose of the Study:
- To investigate the temporal distribution patterns and identify the sources of nitrate pollution in a subtropical watershed.
- To assess the influence of seasonal variations (wet vs. dry) on nitrate concentrations and source contributions.
Main Methods:
- Utilized hydrochemical analysis (major ions, DO) and stable isotope ratios (δ15N-NO3-, δ(18)O-NO3-) to identify nitrate sources.
- Employed a Bayesian model (SIAR) for quantitative apportionment of nitrate sources.
- Monitored water quality parameters over a 10-month period (September 2011 to July 2012).
Main Results:
- Nitrate concentrations peaked in the wet season (May) and were lowest in the dry season (December).
- Four primary nitrate sources were identified: atmospheric deposition (AD), soil nitrogen (SN), synthetic fertilizer (SF), and manure & sewage (M&S).
- Source contributions varied significantly by season: AD and M&S were more dominant in the dry season, while SN and SF contributed more in the wet season. M&S and SF were the major contributors in December and May, respectively.
Conclusions:
- Denitrification was not a significant nitrogen cycling process in this watershed.
- Seasonal variations in precipitation and temperature strongly influence nitrate levels and source contributions.
- Findings provide critical data for implementing targeted agricultural and sewage management strategies to improve water quality in subtropical watersheds.
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