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针对目前塔里木盆地北缘地区存在的土壤盐渍化问题,以新疆塔里木盆地北缘渭干河-库车河三角洲绿洲为例,根据水土环境中盐渍成分时空分异的区域化特征,应用盐渍水土化学场理论,建立变异函数模型定量化模拟其空间分异,求得变异函数后,采用Geostatistical Analyst地质统计分析模块中的Kriging插值方法定量化预测某种盐渍水土环境特征的空间分布,即对渭干河-库车河三角洲绿洲土壤特征(含盐量和电导率)的空间变异性进行分析。结果表明:渭-库绿洲表层土壤电导率和含盐量采用Exponential模型拟合效果比较好。电导率和含盐量的分维数为1.938和1.907,说明表层土壤含盐量的空间依赖性要比电导率的强,即引起表层土壤电导率空间变异中随机因素起决定性作用,而表层土壤含盐量则受结构性因素和随机因素共同作用。表层土壤电导率和含盐量的块金值与基台值之比分别为44.72%和38.61%,具有中等的空间相关性。并且变异系数分别为0.634和0.618。故具有中等变异强度,主要原因在于表层干扰因素较多(大气降水、灌溉、植被覆盖、蒸散发、根系吸水及地表微地形的差异等)。利用在渭干河-库车河三角洲绿洲的实测数据进行验证,可为盐渍水土环境的定量化研究提供理论依据。
According to the existing problems of soil salinization in the northern margin of Tarim Basin, taking the Wegan River and Kuqa River Delta in the northern margin of Tarim Basin, Xinjiang as an example, according to the regional characteristics of temporal and spatial salinities in soil and water environment, Water and soil chemical field theory, the establishment of a model of variation function to quantitatively simulate the spatial variability, find the mutation function, the use of Geostatistical Analyst Geostatistical Analysis module Kriging interpolation method to quantitatively predict the spatial distribution of some saline soil and water environmental characteristics, The spatial variability of soil characteristics (salt content and conductivity) in Weigan-Kuqa River delta oasis was analyzed. The results show that the model of Exponential model is more suitable for the surface soil conductivity and salt content in Wei-Ku reservoir oasis. The fractal dimension of conductivity and salinity were 1.938 and 1.907, which indicated that the spatial dependence of salt content of surface soil was stronger than that of conductivity, that is to say, the random factors in the spatial variability of surface soil conductivity played a decisive role. However, the surface soil Salt content is affected by both structural and random factors. Surface soil conductivity and salt content of the nugget value and abutment value ratio were 44.72% and 38.61%, with a moderate spatial correlation. The coefficients of variation were 0.634 and 0.618, respectively. Therefore, the intensity of medium variation is mainly due to many surface disturbances (precipitation, irrigation, vegetation cover, evapotranspiration, water absorption from the root system and differences in surface microtopography, etc.). Using the measured data from the Wegan-Kuqa River Delta oasis can provide a theoretical basis for the quantitative study of saline soil-water environment.