基于GIS和RS的玛纳斯河流域土壤盐渍化敏感性动态评价

土壤盐渍化是威胁干旱区土壤安全的重要敏感机制之一。本研究以土壤盐渍化形成机制的基础数据集为基础,运用RS和GIS技术对1989年、2000年和2015年的土壤盐渍化敏感性进行评价及动态分析。结果表明:(1)土壤盐渍化高敏感性主要分布在荒漠区和冲积洪积扇扇缘的泉水溢出带,极敏感性分布于玛纳斯湖周围和灌区的部分区域;(2)1989—2000年中度敏感转化为高度、轻度敏感的面积分别为3 342.10、1 910.27 km~2,高度敏感转化为中度、极敏感性的面积分别为1 076.64、1 098.33 km~2。2000—2015年中度敏感向轻度敏感转化了1 410.68 km~2,高敏感向中度敏感转化了2 713.74 km~2;(3)玛纳斯河流域冲积洪积扇扇缘区域和水库周围土壤盐渍化敏感性较高,应加强水资源管理和盐渍化治理;(4)1989-2015年中度敏感性和高度敏感性相互转化较为剧烈,中度敏感的变化呈"V"形,减少大于增加;高度敏感变化呈倒"V"形,减少大于增加,极敏感的面积加了1.9%。土壤盐渍化生态有所改善,冲积洪积扇扇缘盐渍化改善明显。本研究对区域土壤资源安全保护和持续高效利用有重要意义。

Sensitivity Evaluation of Soil Salinization in Manasi River Basin Based on GIS and RS

The sensitivity of soil salinization can reflect the interference degree of the regional ecological environment. The dynamic monitoring of soil salinization sensitivity in 1989—2015 was analysed based on Landsat series remote sensing data by GIS and RS technology. The results indicated that: 1) The high sensitivity was mainly distributed in the desert regions and the alluvial fan margin, while the extreme sensitivity was distributed around Manasi Lake and the irrigation area; 2) The areas of moderate sensitivity changed into height and into light sensitivities were 3342.10 km2 and 1910.27 km2, respectively, and the areas of high sensitivity into moderate and extreme sensitivities were 1076.64 km2 and 1098.33 km2 from 1989 to 2000 years, respectively. The area of moderate sensitivity into light sensitivity was 1410.68 km2, and the area of high sensitivity into moderate sensitivity was 2713.74km2; 3) Soil salinization sensitivity is higher in the alluvial fan margin and the reservoir surrounding of Manasi River Valley, thus the management of water resources and salinization should be strengthened; 4) The changes of moderate sensitivity and high sensitivity into other grades were intense. Moderate sensitivity changed in a "V" pattern, and the decrease was greater than the increase; High sensitivity changed in an inverted "V" pattern, and the decrease was greater than the increase. The area of extreme sensitivity increased by 1.9%. In general, the management of soil salinization achieved certain effects, and the salinization in alluvial fan margin reduced obviously, this study is of significant in maintaining the regional safety and sustainability of soil resources.