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土壤中盐分含量与空间分布是了解多孔介质中水盐运移规律并进而因地制宜提出盐渍土改良措施的关键。利用地统计学,结合地理信息系统(GIS),在面积约为2000 km2的新疆典型盐渍化区渭干河流域布设了土壤取样点43个,测定土壤表层(0-30 cm)盐分及其组成(Ca2+,Mg2+,K+,Na+,SO42-,Cl-,HCO3-)的空间变异性规律。结果表明:Ca2+,HCO3-为正态分布,其余盐分离子符合对数正态分布;半方差分析得出总盐分符合球状模型,Mg2+,K+,Na+,Cl-,SO42-符合指数模型,Ca2+符合高斯模型,而HCO3-则是纯块金效应;盐分离子的变程在14.3~64.1 km之间;盐分离子均表现为中等强度的空间自相关,但程度有所差异。用Kriging插值法对未测点的盐分离子进行最优估计,绘制含量分布图,从而可以更直观地反映研究区土壤盐分离子的空间变异特征。
The content and spatial distribution of salinity in soil is the key to understand the law of water and salt transport in porous media and to propose the improvement measures of saline soil according to local conditions. Using geostatistics and geographic information system (GIS), 43 soil sampling sites were set up in Weigan River Basin, an area of about 2000 km2 in Xinjiang, and the salt content of soil surface (0-30 cm) and its (Ca2 +, Mg2 +, K +, Na +, SO42-, Cl-, HCO3-) were studied. The results showed that Ca2 + and HCO3- were normal distribution and the other salt ions were lognormal distribution. The semi-variance analysis showed that the total salt content was in accordance with the spherical model, the coincidence index model of Mg2 +, K +, Na +, Cl- and SO42-, Gaussian model, while HCO3- is a pure block gold effect; the salt ions have a range of 14.3-64.1 km; salt ions show moderate intensity of spatial autocorrelation, but the degree is different. The Kriging interpolation method is used to estimate the salt ion of unmeasured point and draw the content distribution map, which can more directly reflect the spatial variability of soil salt ions in the study area.