伊犁河谷察南灌区土壤盐分空间变异研究

Spatial Variation of Soil Salinity in the Chanan Irrigated Area in the Ili River Valley

以伊犁河谷察南灌区为研究区,运用EM38电导率仪测定及室内分析相结合的手段,获取土壤电导率值及0~30 cm、30~60 cm、60~100 cm土壤盐分含量。一方面对各土层土壤盐分含量进行了简单的盐渍化分级统计,另一方面应用地统计学方法,对土壤盐分特征因子进行半方差函数分析及空间插值分析。初步研究表明:察南灌区土壤电导率变异系数为1.31,各土层土壤盐分含量变异系数分别为1.31、1.10、1.49,均呈现空间强变异;0~30cm、30~60 cm、60~100 cm土层土壤中,盐化土所占比例分别为25.37%、21.79%、12.11%,形成了比较明显的盐渍化趋势;在空间分布上,土壤电导率及土壤盐分含量自灌区西北至东南方向总体呈现减小的趋势。另外,研究发现灌区各土壤盐分因子具有强烈的空间相关性,空间变异格局主要是结构性因素作用的结果。

The study area is located in the Chanan Irrigated Area in the Ili River Valley,Xinjiang,China. EM38 conductivity meter was combined with laboratory analysis to get the values of soil EC and soil salt content at depths of 0-30 cm,30-60 cm and 60-100 cm. Simple statistical classification was conducted,and the semi-variogram analysis on soil salinity was carried out with geostatistics. The spatial variation of soil salinity was aimed at so as to provide the theoretical support for soil salt control and soil desalinization in the similar irrigated areas. Preliminary study indicated that the variation coefficient of soil EC in the study area was 1. 31,and the variation coefficients of soil salt content at three depths mentioned above were 1. 31,1. 10 and 1. 49 respectively. The proportion of nonsalinized soil at each layer was high,but the influence of soil salinization could not be ignored. Salinized soil was mainly distributed in the northwest and southwest regions,the proportions of salinized soil at the three depths were25. 37%,21. 79% and 12. 11% respectively,and the trend of soil salinization in the study area was obvious. Spatially,soil EC and soil salt content were holistically decreased from the northwest to the southeast of the irrigated area. It was found that there were the high spatial correlations among the factors related to soil salt content,and the spatial variation pattern was closely related to the structural factors.