δ^<15>N値利用による地下水硝酸起源推定法の考案と検証

概要

論文の詳細を見る
Origins of nitrate were estimated by using the δ^<15>N values and the concentrations of groundwater nitrate (the δ^<15>N value method) at 9 sites in Miyakojima Is., Okinawa. Groundwater basins in the island are divided into 22 and the flows are separated rather clearly. Under the natural and socio-economic conditions, the sources of the groundwater nitrate are consisted to be the chemical fertilizer, animal waste, domestic waste and soil nitrogen. In this method, the δ^<15>N values of groundwater nitrate derived from the chemical fertilizer, both the animal and domestic waste, and the soil were hypothetically set to be 0,15 and 7‰, respectively. The method was verified by contrasting it with the land use data method, which estimates origins and concentrations of groundwater nitrate by the data on land use such as the human and livestock population and arable land area, as well as on rainfall and their loading factors to the groundwater, on each basin. The results are as follows. 1) Results on groundwater nitrate estimated by the land use method were highly coincident with the actual surveyed ones which represent the water of a basin. So, the method was thought to be effective to verify the δ^<15>N value method. 2) The method showed that the groundwater nitrate was composed of 40.3,16.4,27.0 and 16.3%, respectively, derived from chemical fertilizer, animal waste, domestic waste and soil nitrogen. 3) The component ratio of nitrate on 9 sites estimated by the δ^<15>N value method indicated that nitrates derived from chemical fertilizer were in the range of 27.0-58.2%, 12.1-57.7% from both animal and domestic waste, and 12.2-41.2% from soil nitrogen. 4) Results by the δ^<15>N value method on groundwater sample which represent water of a basin were highly coincident with the results by the land data use method. It suggests the δ^<15>N value method has high possibility to detect the nitrate sources of groundwater when the sample represents a basin.
社団法人日本土壌肥料学会の論文
1995-10-05

δ^<15>N値利用による地下水硝酸起源推定法の考案と検証

スポンサーリンク

概要

著者

関連論文

スポンサーリンク