基于地统计学方法的农田防护林网环境场特征分析

Application of geostatistics in the research of environmental field of farmland protection forest

将地统计学方法引入到农田防护林环境场的分析中,分析了辽宁省昌图县典型林网内春夏两季风速、土壤含水量、土壤温度等环境因子的空间分布特征。结果表明:1)春夏两季风速、土壤温度、土壤含水量的频率分布均基本服从正态分布,其各变异均与空间取样尺度相关,且结构性因素的影响占主要地位。2)春季风速明显大于夏季,但变异程度小于夏季;风速随着高度的增加而增大,但变异程度夏季随高度增加而减小,春季相反。春季1m高风速、春季2m高风速和夏季1m高风速的变异均可拟合为指数模型,夏季2m高风速可拟合为球状模型。空间自相关范围为春季1m高风速>夏季1m高风速>春季2m高风速>夏季2m高风速;其正相关尺度分别为春季≤200m,夏季≤128m。结构性因素所占比重为夏季2m高风速>夏季1m高风速>春季1m高风速>春季2m高风速;分维数D为夏季1m高风速<春季1m高风速<春季2m高风速<夏季2m高风速。3)春夏两季土壤温度变异均为球状模型;空间自相关范围为春季>夏季;结构性因素所占比重为夏季>春季;分维数D为夏季>春季。在中尺度内具有明显的空间相关性格局,其空间正相关性存在尺度为春季<282m、夏季<127m。4)春夏土壤水分变异均可拟合为指数模型;空间自相关范围为春季>夏季;结构性因素所占比重为夏季>春季;分维数D为春季<夏季;在中尺度上具有明显的空间相关性。春季和夏季土壤水分空间正相关尺度<100m。

In this study,the goestatistical method was applied to analyze the environmental field of farmland protection forest in Changtu County,Liaoning Province. Environmental factors,including wind speed,soil moisture content,and soil temperature of typical forest networks,were measured both in spring and summer,and the spatial characteristics of environmental factors were analyzed. Results indicated that the wind speed,soil temperature and soil moisture content in spring and summer all followed a normal distribution. The variances were related to spatial scale,and the structural factors were main causes. Wind speed in spring was much higher than that in summer;but the degree of variation was smaller than that in summer. Simultaneously,wind speed increased with height both in spring and summer;variation degree decreased with height in summer but increased in spring. The variance of wind speed all fit a exponential model except that at 2 m height in summer which fit a spherical model. The rank of spatial autocorrelation of wind speed was 1 m in spring 〉1 m in summer 〉2 m in spring 〉2 m in summer,and the positive correlation was ≤200 m in spring and ≤128 m in summer. The rank of heterogeneity percentage caused by spatial structure was 2 m in summer 〉1 m in summer 〉1 m in spring 〉2 m in spring,and the fractal dimension D was 1 m in summer 〈1 m in spring 〈2 m in spring 〈2 m in summer. The soil temperature in spring and summer both fit a spherical model,and the spatial autocorrelation in spring and summer was 〈282 m and 〈127 m,respectively. Both the heterogeneity caused by spatial structure and fractal dimension D were bigger in summer than that in spring. The soil moisture in spring and summer both fit a exponential model. The spatial autocorrelation in spring was bigger than that in summer,which was both less than 100 m. Both the heterogeneity caused by spatial structure and fractal dimention D were bigger in summer than that in spring.