再生水灌区地下水硝态氮空间变异性及污染成因分析  

Spatial variability of groundwater nitrate-nitrogen and cause analysis of its pollution for irrigation area with reclaimed water

作　　者：尹世洋[1,2] 吴文勇[1,2] 刘洪禄[1,2] 张先权 

机构地区：[1]北京市水利科学研究所,北京100048 [2]北京市非常规水资源与节水工程技术研究中心,北京100048 [3]北京市水利建设管理中心,北京100036

出　　处：《农业工程学报》2012年第18期200-207,F0002,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：水利部公益项目-东南郊水网再生水利用对地下水影响的研究(201101051);北京市非常规水资源开发利用与节水工程技术研究中心2011年阶梯计划项目(Z111105055311091);2012年度北京市优秀人才资助课题再生水输配过程对地下水影响的试验研究与数值模拟

摘　　要：为了深入了解北京市再生水灌区地下水硝态氮空间分布规律及污染成因,该文基于地统计学理论、结合ArcGIS软件的地统计分析功能,绘制表达了该区域地下水硝态氮随机性和结构性的半变异函数图和空间分布图。结果表明,研究区域地下水硝态氮含量服从对数正态分布,且与1阶高斯克里格模型拟合最好,从获得的参数可知,地下水硝态氮的空间变程为9639.36m,为反应灌区硝态氮的分布特征,2个监测点的距离不应大于变程;其块金效应为0.43,表明地下水中的硝态氮含量的变化是结构性因素与人为因素共同作用的结果,同时还发现土地利用类型、地下水的开采强度与区域地下水是否容易遭受硝态氮的污染有很大的相关性,监测井深度越小、地下水位降幅越大,地下水硝态氮增幅越大,再生水蓄积区(坑塘水面)对应区域产生地下水硝态氮污染的风险较小。研究结果可为再生水的安全利用提供参考。To analysis the spatial distribution of groundwater nitrate-nitrogen and its pollution causes of reclaimed water irrigation region in Beijing,based on geostatistics model and geostatistical analyst module of ArcGIS.The spatial distribution maps of groundwater nitrate-nitrogen and semi-variogram function was proposed,which represented the probability and structural characteristics.The results showed that the groundwater nitrate-nitrogen satisfied log normal distribution and one-order Gaussian model can capture the characteristics well in the reclaimed water irrigation region.The prediction of distance statistical correlation of groundwater nitrate-nitrogen was 9639.36 m,and the distance between two sampling sits should be smaller than this value.The nugget effect value was 0.43,which implied that nitrate-nitrogen concentration distribution was controlled by structural factors and human activity.Land use style and groundwater withdrawal intensity directly influenced the probability of groundwater nitrate-nitrogen pollution.The depth of monitoring wells was smaller,the decline of groundwater level was greater,the increase in groundwater nitrate-nitrogen was greater.The risk of nitrate-nitrogen pollution of groundwater caused by accumulated areas of reclaimed water maintained low.The study provides a reference for quantifying the groundwater pollution risk and security of wastewater utilization in agriculture.

关 键 词：灌溉 污染 氮 地下水 硝态氮 空间变异 

分 类 号：Q689[生物学—生物物理学] S129[农业科学—农业基础科学]