Babiker Insaf S, Mohamed Mohamed A A, Terao H, Kato Kikuo, Ohta Keiichi
Laboratory of Stable Isotopes, Hydrospheric Atmospheric Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Environ Int. 2004 Feb;29(8):1009-17. doi: 10.1016/S0160-4120(03)00095-3.
This study employed the Geographical Information System (GIS) technology to investigate nitrate contamination of groundwater by agrochemical fertilizers in the Kakamigahara Heights, Gifu Prefecture, central Japan. Thematic information and chemical data of groundwater from the Heights were analyzed in a GIS environment to study the extent and variation of nitrate contamination and to establish spatial relationships with responsible land use types. The high and correlated concentrations of Ca(2+), Mg(2+), SO(4)(2-), and NO(3)(-) reflected the polluted nature of the unconfined highly permeable Kakamigahara aquifer. Ninety percent of the water samples showed nitrate concentrations above the human affected value (3 mg/l NO(3)(-)), while more than 30% have exceeded the maximum acceptable level (44 mg/l NO(3)(-)) according to Japan regulations. The spatial analyses indicated that groundwater contamination by nitrate is closely associated with one specific land use class, the "vegetable fields". The nitrate concentration of groundwater under vegetable fields was significantly higher than that under urban land or paddy fields. Most of the unacceptable nitrate levels were encountered in boreholes assigned to "vegetable fields" but a few were also found in boreholes allotted to "urban" class. Therefore, the vegetable fields were considered the principal source of nitrate contamination of groundwater in the Kakamigahara. However, contamination from urban sources is also possible.
本研究采用地理信息系统（GIS）技术，调查日本中部岐阜县各务原高地农用化肥对地下水的硝酸盐污染情况。在GIS环境中分析了该高地地下水的专题信息和化学数据，以研究硝酸盐污染的程度和变化，并建立与相关土地利用类型的空间关系。Ca(2+)、Mg(2+)、SO(4)(2-)和NO(3)(-)的高浓度且相互关联，反映了无压高渗透性各务原含水层的污染性质。90%的水样硝酸盐浓度高于人类影响值（3毫克/升NO(3)(-)），而根据日本规定，超过30%的水样超过了最大可接受水平（44毫克/升NO(3)(-)）。空间分析表明，硝酸盐对地下水的污染与一种特定的土地利用类型“菜地”密切相关。菜地下面的地下水硝酸盐浓度明显高于城市土地或稻田下面的地下水。大部分不可接受的硝酸盐水平出现在划归“菜地”的钻孔中，但在划归“城市”类别的钻孔中也发现了一些。因此，菜地被认为是各务原地下水硝酸盐污染的主要来源。然而，城市来源的污染也有可能。
