Quantification and simulation of nutrient sources at watershed scale in Mississippi
Quantification and simulation of nutrient sources at watershed scale in Mississippi
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DOI：
10.1016/j.scitotenv.2019.03.233
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发表时间：
2019-06-20
影响因子：
9.8
通讯作者：
Parajuli, Prem B.
中科院分区：
文献类型：
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作者：
Risal, Avay;Parajuli, Prem B.
各种点源和非点源产生的过量营养物质使水的质量恶化。为了减少流域的养分，需要对其进行量化，然后实施适当的管理实践。在本研究中，对大向日葵河流域（BSRW）的主要养分来源进行了识别和量化，并应用水土评估工具（SWAT）模型对流量、沉积物和养分进行了评估。 SWAT 针对 BSRW 内的三个联合斯塔尔斯地质调查局 (USGS) 测量站的水流、沉积物、总氮 (TN) 和总磷 (TP) 进行了校准和验证。此外，还根据农业运营和最佳管理实践开发了不同的场景。使用纳什-苏特迪夫效率 (NSE) 和决定系数 (R-2) 评估 SWAT 的性能。在校准和验证过程中，streamilow 的性能良好，R-2 和 NSE 范围分别为 0.74 至 0.90 和 0.70 至 0.82。 SWAT 对沉积物、TN 和 TP 的表现令人满意，但在少数极端条件下（动物粪便与农田径流混合）除外。这项研究为 BSRW 养分的有效管理提供了合适的轮作和管理实践。在完全种植大豆的田地施用粪肥是减少 TN 的最佳做法，R-2 和 NSE 范围分别为 0.70 至 0.90 和 058 至 0.76。仅在现有大豆农田上施用粪肥是减少 TP 的最佳做法，R-2 和 NSE 分别为 051 至 0.69 和 0.41 至 0.60。大豆能有效地从土壤中积累氮和磷。这项研究将有助于通过适当的作物轮作和管理实践来有效规划和管理养分。 (C) 2019 Elsevier B.V. 保留所有权利。
Excessive quantity of nutrient produced from various point and non-point source deteriorates the quality of water. For reduction of nutrient from a watershed, it is needed to be quantified followed by implementation of appropriate management practices. In this study, major sources of nutrient in Big Sunflower River Watershed (BSRW) were identified, quantified, and Soil and Water Assessment Tool (SWAT) model was applied for assessment of flow, sediment and nutrient. SWAT was calibrated and validated for streamflow, sediment, total nitrogen (TN), and total phosphorus (TP) for three United Stales Geological Survey (USGS) gauge stations within BSRW. Moreover, different scenarios, based on agricultural operation and best management practices, were developed. Performance of SWAT was evaluated using Nash-Sutdiffe Efficiency (NSE) and coefficient of determination (R-2). The performance was good for streamilow during calibration and validation with R-2 and NSE ranging from 0.74 to 0.90 and 0.70 to 0.82 respectively. SWAT performed satisfactorily for sediment, TN and TP except in few extreme conditions, where animal waste was mixed with farm runoff. This study has provided a suitable crop rotation and management practice for efficient management of nutrient in BSRW. Manure applied on field cultivated entirely with soybean was the best practice for reduction of TN with R-2 and NSE ranging from 0.70 to 0.90 and 058 to 0.76 respectively. Application of manure only on existing soybean crop-land was the best practice for reduction of TP with R-2 and NSE ranging from 051 to 0.69 and 0.41 to 0.60 respectively. Soybean was effective in accumulating both nitrogen and phosphorus from soil. This study will be helpful for efficient planning and management of nutrient through suitable crop rotation and management practice. (C) 2019 Elsevier B.V. All rights reserved.