吉林西部大安灌区土壤贮水能力空间变异特征及土壤水分有效性

为研究吉林西部土壤贮水能力的空间分布特征和水分有效性,以吉林西部大安灌区为研究对象,通过试验测定土壤贮水量及根系区土壤的水分特征曲线,并利用van Genuchten模型进行水分特征曲线拟合,结合经典统计和地统计分析方法分析土壤贮水量空间变异特征。结果表明:盐碱土和非盐碱土吸持贮水量、滞留贮水量和饱和贮水量的均值之间不存在显著性差异(P0.05),实际贮水量均值存在显著差异(P0.05);土壤实际贮水量呈现由西向东、由北向南逐渐升高的变化趋势,且南北方向的空间变异性均高于东西方向的空间变异性;轻度盐碱地、水田和旱田实际有效含水量分别占其最大有效含水量的78.94%、58.28%和56.62%,水分有效性较高,蔬菜地、高粱地、草甸土以及中度和重度盐碱土实际有效含水量占其最大有效含水量的20.83%27.13%,土壤水分有效性较小;水田、轻度和中度盐碱地的贮水和持水能力强,旱田和蔬菜地土壤贮水能力较强,持水能力中等,而重度盐碱地、高粱地、草甸土等土壤的持贮水能力较弱。研究结果对旱改水工程水资源管理和预防次生盐渍化有重要意义。

Spatial Distribution of Soil Water Storage Capacity and Soil Water Availability in West Jilin Province

Analyses of spatial distribution of soil water storage capacity (SWSC) and soil water availability is of great significance for water resources management.Through samples collection in Daan irrigation district,the SWSC were tested and then the spatial variation characteristics were analyzed with classical statistics and geostatistics.The soil water characteristic curves were measured and fitted with the van Genuchten model.Results showed that:There was no significant difference for mean values of the holding SWSC,retained SWSC and saturated SWSC between saline-alkali soil and non-saline-alkali soil,while for mean values of actual SWSC,there was significant difference;The actual SWSC increased from west to east and from north to south;It had larger water availability for light saline-alkali soil,rice land soil and dry land soil with the actual effective water contents were 78.94％,58.28％ and 56.62％ of their maximum effective water contents,while the water availability of vegetable soil,sorghum soil,grassland soil and medium-severe saline-alkali soil was less than rice land soil and dry land soil.Therefore,the SWSC and water retention capacity of the rice land soil and light and medium saline-alkali soils were the strongest,and then were the dry land soil and vegetable land soil,the SWSC of the severe saline-alkali soil and sorghum soil and grassland soil were the weakest.The light and medium salinealkali soils were suitable to be transformed to rice land.The research results were great significance for prevention of soil secondly salinization and harmonizing agricultural water use in Daan irrigation district in west Jilin Province.