【作者】 刘燕；

【导师】 郭建青； 樊向阳；

【作者基本信息】 长安大学 ， 水文学及水资源， 2014， 硕士

【摘要】 河南省新乡市是我国典型的污灌区，长期大面积的污灌导致严重的土壤污染，土壤重金属污染引发的环境和粮食安全问题迫切需要解决。本文应用地统计学的方法对新乡市污灌区麦田在清灌和污灌不同灌溉条件下，不同土壤深度的土壤重金属Cd的有效态、有机质含量和pH值的空间分布特性进行了分析讨论，取得的主要结果为：1.采用单样本K-S检验和Q-Q检验两种方法对不同试验区不同深度土层的有效Cd含量、有机质含量、pH值进行正态分布检验，对不服从正态分布的数据进行对数转换。在此基础上，通过对土壤不同指标的平均值、变异系数、偏度、峰度等统计参数的分析表明：清灌区灌水前土壤有效Cd含量的均值整体较灌水后大，而污灌区相反。清灌区和污灌区不同土层整体上灌水后的有机质含量小于灌水前。清灌区和污灌区各层土壤有效Cd含量和有机质含量随土壤深度的增加而减小，而pH值的变化范围小，但是随着土壤深度的增加没有明显的变化趋势。不同试验区灌水前后有效态Cd含量和有机质含量的变异系数均大于10%，小于90%，属于中等空间变异，而pH值的变异系数均小于10%，为弱空间变异。2.利用半方差函数理论建立了最优半方差函数模型，得到不同试验区灌水前后各土层不同指标的半方差函数模型及其参数。通过讨论得知，除污灌区灌水后20-30cm土层有效Cd含量和清灌区灌水后0-10cm土层有机质含量的块基比大于0.75，属于弱空间相关性及清灌区灌水前10-20cm土层pH值属于中等空间相关性外，清灌区和污灌区灌水前后其余土层各指标含量的块基比均小于0.25，属于强空间相关性。3.根据Kriging最优无偏内插方法，在surfer软件平台上绘制不同试验区各土层有效Cd含量、有机质含量和pH值的等值线图，显示土壤有效态Cd含量、有机质含量和pH值在研究区南北方向的的空间变异性较强。更多还原

【Abstract】 Xinxiang City in Henan Province, is a typical sewage irrigation area, a large area of long-termsewage irrigation led to serious soil pollution, environment and food safety issues caused byheavy metal contamination in soil urgent need to address. In this paper, geostatistics is used todiscuss and analyz the spatial variation characteristics of soil heavy metals in soil Cd ofeffective state, organic matter and pH in Xinxiang sewage irrigated wheat field in differentdepths of the clear water irrigation and sewage irrigation under different irrigation conditions,this paper provides an important basis for the soil environment, the main results are asfollows:1. Using a single sample K-S test and Q-Q test to test if the datas of soil Cd content, organicmatter content and pH value of every layer in accordance with normal distribution, on theother hand, for non-normally distributed data logarithmic transformation. On this basis,through the mean coefficient of variation, skewness, kurtosis and other statistical parametersof different indicators of soil analysis show that: the average overall clear water irrigationirrigated soil available Cd content before the irrigation is larger than the content which afterirrigation, while the case of sewage irrigation is opposite. As organic matter content of clearwater irrigation and sewage irrigation, after less than before irrigation. Layers of soil Cdcontent and organic content in the case of clear and sewage irrigation with increasing soildepth decreases, while a small range of pH value change with increasing soil depth noobvious trends. Coefficient of variation of Cd content and organic matter content before andafter irrigation in different test areas greater than10%and less than90%, which is moderatespatial variability and the coefficient of variation of pH less than10%, which is weak spatialvariability.2. The use of semi-variance optimal fitting function theory Semivariance get a different testarea before and after each irrigation different indicators of soil semivariogram model and itsparameters, the results showed that, spatial correlation of Cd concent in20-30cm layer aftersewage irrigation and organic matter content in0-10cm layer after cleaning irrigation belongweak spatial correlation, in addition, spatial correlation of pH value befor cleaning irrigationin10-20cm layer belong moderate spatial correlation, spatial correlation of Cd content, organic matter content and pH value in the rest of the layer before and after cleaning irrigationand sewage irrigation belong strong spatial correlation.3. According to the Kriging interpolation method, draw the contour maps of soil Cd content,organic matter content and pH of each different test areas on the surfer software platform,which show that spatial variability of soil Cd content, organic matter content and pH innorth-south direction in the study area belong large spatial variability.更多还原