Modeling of nitrate runoff from agricultural watershed

农业流域硝酸盐径流建模

• 批准号: 16580042
• 负责人: NAKAHARA Osamu
• 金额: $ 2.37万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16580042/
• 关键词: Nutrient Cycling; Agro-ecosystem; Nitrogen Cycling; Nitrogen Fertilizer; Nitrate; Eutrophication; Nitrogen Removal; Agricultural Management; 硝酸溶脱

In Shibetsu watershed that is located in eastern Hokkaido, about 25% of net nitrogen input (NNI) was nitrified into nitrate form and discharged into rivers without removal by plant uptake and denitrification. The nitrate runoff causes eutrophication in coastal and brackish area and often results in degradation of environment of these area and severe damage on fishery. Therefore, we need to establish the management to minimize the nitrate runoff.In this study, we aimed to make model that predicts rate of nitrate removal in deeper soil horizon in two dimension with watershed scale. In this model we assumed that the nitrate removal reaction (mainly denitrification reaction) mediated by microbes obey first order reaction. The time term in this kinetic reaction was replaced by the ratio of distance between the point of nitrogen load and nearest river by using Hydrology Extension in ArcGIS 9.0. From field observation, we found empirical rule that nitrate concentration in rivers negatively correlated with slope of rivers.This model explained 94% of spatial variation in nitrate concentration in rivers in Shibetsu watershed. The predicted rate of nitrate removal by denitrification amounted from several percent to fifty percent. The rate of removal depended on size of watershed and average slope in the watershed.Further effort is needed to give sound theoretical proof to the empirical relationship between nitrate concentration in rivers and the slope of the river. In this study, we tried to prove the relationship by using Manning's law and Leopold's empirical law but failed to give final answer.

在北海道东部的石别流域，约25%的净氮输入（NNI）被硝化成硝酸盐形式排放到河流中，而不被植物吸收和反硝化去除。硝态氮径流引起沿海和半咸淡水地区富营养化，往往导致该地区环境退化，对渔业造成严重损害。因此，我们需要建立管理，以尽量减少硝酸盐的径流。在本研究中，我们旨在建立具有流域尺度的土壤深层硝酸盐去除速率的二维预测模型。在该模型中，我们假设微生物介导的硝酸盐去除反应（主要是反硝化反应）服从一级反应。利用ArcGIS 9.0中的Hydrology Extension软件，将该动力学反应的时间项替换为氮负荷点与最近河流的距离之比。通过野外观测，发现河流中硝酸盐浓度与河流坡度呈负相关的经验规律。该模型解释了石别津流域河流硝酸盐浓度94%的空间变异。预测反硝化对硝酸盐的去除率为百分之几到百分之五十。去除速率取决于流域的大小和流域的平均坡度。需要进一步努力，为河流中硝酸盐浓度与河流坡度之间的经验关系提供可靠的理论证明。在本研究中，我们试图通过曼宁定律和利奥波德经验定律来证明两者之间的关系，但未能给出最终的答案。

项目成果

続・環境負荷を予測する モニタリングとモデリングの発展

预测环境影响的监测和建模方面的进展

• 发表时间: 2005
• 作者: 波多野隆介;犬伏和之(編)
• 通讯作者: 犬伏和之(編)

Modeling of nitrate removal in agricultural watershed, Prediction of Environmental Load (Hatano and Inubushi (eds.))(in Japanese)

农业流域硝酸盐去除模型、环境负荷预测（Hatano 和 Inubushi（编辑））（日语）

• 作者: 波多野隆介;犬伏和之(編);Nakahara
• 通讯作者: Nakahara

Modeling of nitrate removal in agricultural watershed

农业流域硝酸盐去除建模

• 期刊: In (Hatano and Inubushi (eds.)) Prediction of Environmental Load (Hatano and Inubushi (eds.))(in Japanese)
• 作者: Hatano;Inubushi;Sawamoto;Shirato;Nakahara;Matsumori;Nakahara
• 通讯作者: Nakahara

環境負荷予測への土壌学的展開

环境负荷预测的土壤科学发展

• 发表时间: 2004
• 期刊: 日本土壌肥料学会誌 75
• 作者: 波多野隆介;犬伏和之;澤本卓治;白戸康人;中原 治;松森堅治
• 通讯作者: 松森堅治

Prediction of Environmental Load from Agriculture

农业环境负荷预测

• 期刊: Japanese Journal of Soil Science and Plant Nutrition (in Japanese with English summary) 75
• 作者: Hatano;Inubushi;Sawamoto;Shirato;Nakahara;Matsumori
• 通讯作者: Matsumori