Source contribution analysis of nutrient pollution in a P-rich watershed: Implications for integrated water quality management
Source contribution analysis of nutrient pollution in a P-rich watershed: Implications for integrated water quality management
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富磷流域营养物污染的来源贡献分析：对综合水质管理的影响
DOI：
10.1016/j.envpol.2021.116885
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发表时间：
2021-03-18
影响因子：
8.9
通讯作者：
Zheng, Yi
中科院分区：
文献类型：
--
作者：
Han, Jianxu;Xin, Zhuohang;Zheng, Yi
在流域尺度上解决各种点源和非点源引起的营养盐污染问题仍然是一个巨大的挑战。基于流域建模的污染源贡献分析可以帮助流域管理者识别主要污染源，提出有效的管理方案，并做出明智的决策。本研究以大连市登沙河流域为例，展示了一种解决流域尺度水污染问题的技术程序。通过考虑土壤养分浓度的约束条件，对SWAT模型进行了改进，氮（N）和磷（P），当模拟典型作物玉米的养分吸收时。然后利用改进的SWAT模型定量分析了各污染源对DRW中N、P污染的贡献。结果表明，种植业和跨行政区污水排放是营养盐污染的两个主要来源。本研究进一步研究了不同施肥方案对养分流失和作物产量的影响。结果表明，氮肥是作物产量的限制因素，过量的磷储存在DRW的农业土壤中。建议氮肥施用量约为当前施用量的40%，以平衡水质和环境保护与作物生产。通过100年的未来模拟研究了遗留磷的长期影响，结果表明，即使在停止施磷后，作物的生长仍可以维持12年。我们的研究强调，需要考虑来源归属，施肥和传统的磷在农业为主的流域的影响。本研究的分析框架可为其他研究领域制定适应性和可持续的养分管理策略提供科学合理的程序。? 2021爱思唯尔有限公司保留所有权利。
It is still a great challenge to address nutrient pollution issues caused by various point sources and non point sources on the watershed scale. Source contribution analysis based on watershed modeling can help watershed managers identify major pollution sources, propose effective management plans and make smart decisions. This study demonstrated a technical procedure for addressing watershed-scale water pollution problems in an agriculture-dominated watershed, using the Dengsha River Watershed (DRW) in Dalian, China as an example. The SWAT model was improved by considering the constraints of soil nutrient concentration, i.e., nitrogen (N) and phosphorus (P), when modeling the nutrient uptake by a typical crop, corn. Then the modified SWAT model was used to quantify the contributions of all known pollution sources to the N and P pollution in the DRW. The results showed that crop production and trans-administrative wastewater discharge were the two dominant sources of nutrient pollution. This study further examined the responses of nutrient loss and crop yield to different fertilizer application schemes. The results showed that N fertilizer was the limiting factor for crop yield and that excessive levels of P were stored in the agricultural soils of the DRW. An N fertilizer application rate of approximately 40% of the current rate was suggested to balance water quality and environmental protection with crop production. The long-term impact of legacy P was investigated with a 100-year future simulation that showed the crop growth could maintain for 12 years even after P fertilization ceased. Our study highlights the need to consider source attribution, fertilizer application and legacy P impacts in agriculture-dominated watersheds. The analysis framework used in this study can provide a scientifically sound procedure for formulating adaptive and sustainable nutrient management strategies in other study areas. ? 2021 Elsevier Ltd. All rights reserved.