黄淮海平原浅层地下水中NO_3-N含量的空间变异与分布特征

Spatial Variability and Distribution of Nitrate Content of Shallow Groundwater in Huang-Huai-Hai Plain

通过GPS定位取样分析和GIS处理 ,研究了黄淮海平原浅层地下水中NO3-N含量的空间变异和分布特征。结果表明 ,黄淮海平原浅层地下水中NO3-N含量在 35～ 5 0km的取样密度下 ,没有半方差结构 ,各取样点之间变异性较大 ;黄淮海平原有 10 %的面积浅层地下水中NO3-N含量超过 2 0mg·L-1,主要分布在天津至济南一线和淮河流域的新蔡、阜阳和蚌埠一带。徐州至连云港一带的苏北地区及山东的潍坊地区 ,浅层地下水中的NO3-N含量一般在 10～ 2 0mg·L-1之间 ,约占黄淮海平原总面积的 11 5 %。浅层地下水中NO3-N的含量与地下水埋深密切相关 ,NO3-N含量超过 2 0mg·L-1的地下水埋深一般在 3m以上 ,地下水埋深在 10m以下时 ,其中的NO3-N含量均不超过 10mg·L-1。这表明 ,目前通过土壤NO3-N的淋失对该区地下水中NO3-N含量影响深度一般不超过 10m。此项研究结果对于黄淮海平原持续发展 ,制定优化的高效水肥管理措施和方案有一定指导意义。

The spatial variability and distribution of NO 3-N in shallow groundwater in Huang Huai Hai Plain were studied by means of GPS and GIS technology The results indicated that it did not show a spatial structure at the sampling density of 35～50 km in shallow groundwater The spatial variability of NO 3-N content belonged to high intensity The area of NO 3-N concentration over 20 mg·L -1 was about 10% of the whole Huang Huai Hai Plain, and was mainly distributed in the zone from Tianjin to Jinan and Xincai, Fuyang and Bengbu in the Huaihe River Basin The area of NO 3-N content in the range of 10-20 mg·L -1 was distributed in the region from Xuzhou to Lianyungang in Jiangsu Province and Weifang,in Shandong Provence, which was about 11 5% of the Huang Huai Hai Plain The NO 3-N concentration in the shallow groundwater was related to the groundwater depth The NO 3-N concentration was usually over 20 mg·L -1 when the groundwater level was less 3 m, while the NO 3-N content was less 10 mg·L -1 when the groundwater level was over 10 m It implied that the affecting depth of the nitrate leaching on the groundwater was less than 10 m These results were beneficial to making decision for increasing water and fertilizer utilization efficiency and to the sustaining agricultural development in Huang Huai Hai Plain