内陆河流域绿洲灌区盐碱地改良分区及治理模式探究——以新疆焉耆县平原灌区为例

干旱区土壤盐碱化是土地退化的主要问题,并威胁着绿洲农业的可持续发展,而盐碱地改良分区是因地制宜、综合治理盐碱地的前提。通过综合运用地理信息系统的各种空间数据分析功能,以焉耆平原灌区为典型区域,将土地盐碱化现状分为:非盐碱地、轻度盐碱地、中度盐碱地、重度盐碱地、盐土等5个区,并结合地下水、土壤、植被、岩性等调查资料,进行成因分析,建立了内陆河流域绿洲灌区盐碱地改良分区模型。立足土地盐碱化的现状,充分考虑地下水埋深和矿化度,把焉耆平原灌区按改良难易程度分为:易改良区、较难改良区、难改良区、不宜改良区,并针对不同的盐碱地改良分区特征、水盐平衡模型和现状灌排模式,提出了相应的综合治理对策。

Study on Control Mode and Amelioration Regionalization for Salt-affected Land in oasis Irrigation District of Inland River Basin

Soil salinization in arid areas is the major factor for the land degradation and has seriously influenced the sustainable development of oasis agriculture.Regionalization of salt-affected land is the precondition for effective amelioration.In this paper,using various remote data analysis functions of GIS and taking the Yanqi plain irrigation district as a typical example,the present soil salinization zone was divided into five zones,namely normal land,light-degree salt-affected land,middle-degree salt-affected land,serious-degree salt-affected land and salty land.Combining with the investigation data of groundwater,soil,vegetation and lithology,the cause for land salinization was analyzed and the model for amelioration regionalization of salt-affected land in oasis irrigation district of inland river basin was established.Based on the present situation of soil salinization,considering the condition of groundwater depth and mineralization degree,the Yanqi plain irrigation district was regionalized to four zones,namely easy amelioration region,relatively difficult amelioration region,difficult amelioration region and unfavorable amelioration region.Furthermore,different control countermeasures for ameliorating saline soils were put forward according to the regional characteristic,water and soil balance model and present irrigation and drainage mode.