玛河灌区膜下滴灌棉田表层土壤盐分空间变异性

摘要

应用区域采样点数据,结合地统计学与空间简单克里金插值等分析方法,分析了玛纳斯河流域中游平原灌区膜下滴灌棉田表层土壤盐分的空间变异性.结果表明:棉花采收后表层土壤含盐量变异系数为35.617％,表现为中等强度变异性,服从正态分布;具有强二阶趋势效应,灌区中部趋势影响力变化剧烈;块金系数小于25％,具有很强的空间相关性,其变异主要受空间结构性因素的影响;沿等高线方向表现为各向异性,垂直等高线方向表现为各向同性;棉花采收后表层土壤含盐量具有明显的连续变化,灌区内不存在盐土、重度盐化土和中度盐化土,轻度盐化土在整个灌区占主导地位并广泛分布于各子灌区,非盐化土主要分布在南部山前地区和东北局部地区.%Using the methods of geostatistics and simple Kriging interpolation,this research investigated the spatial variation of surface soil salinity in the under-film drip irrigated of cotton field in plain irrigation areas of middle reaches of Manas River.The results showed that the variation coefficient of surface soil salinity after harvesting was 35.62％,presenting the moderate-intensity variability and following the normal distribution,meanwhile exhibiting a strong second-order trend effect especially for the midland.Isotropic semivariogram showed that Nugget coefficient was less than 25 ％,indicating that soil salinity had a strong spatial correlation under the influence of structural factors.Surface soil salinity after harvesting showed an anisotropy along the contour line and the isotropy perpendicular to the contour line,respectively.The spatial distribution of surface soil salinity after harvesting presented an obviously and continuously changing trend,and the moderate salinized soil,heavy salinized soil and saline soil were not detected in the research region.The mild salinized soil dominated the subsidiary irrigated areas,while the non-salinized soil was mainly located in the northeast region and mountain front area of southem region.