干旱区绿洲土壤盐渍化动态变化及其影响因子分析研究—以渭干河-库车河三角洲绿洲为例

目的]土地盐渍化是干旱、半干旱地区由于人类不合理的开发土地资源活动和脆弱的生态环境相互影响而引起的土地退化问题,它严重威胁着干旱区绿洲生态环境的稳定性,约束着社会经济的可持续发展.因此,监测盐渍地的分布范围及其盐渍化程度,分析其成因对绿洲生态环境和社会经济可持续发展有着重要的意义.方法]以塔里木盆地北缘盐渍地普遍发育区域渭干河-库车河三角洲绿洲为例,利用 1989年TM,2001年ETM +和2007年ALOS 3个时期的遥感影像数据,在野外调查的基础上,采用监督分类方法,进行了盐渍地动态变化分析研究.结果]1989～2007年的19 a中,重度盐渍地面积从1 177.78 km2增加到1 192.33 km2,中度盐渍地面积增加了1 353.25 km2,轻度盐渍地面积减少了3.40;,总盐渍地面积呈增加趋势,增加面积为981.30 km2.结论]盐渍化影响因子中人为因素占主导地位.对水和土地资源需求的增加以及不合理利用导致了该区域生态环境的恶化,进一步加重了盐渍化问题.

Study on Dynamic Change and Cause Analysis of Soil Salinization in Arid Oasis:A Case Study in the Delta Oasis of Weigan and Kuqa Rivers

【Objective and Method】Soil salinization is a land degradation problem which is mainly caused by inter-effecting between the unreasonable human activity for developing land resource and frail eco-environments in the arid and semi-arid regions.It has threatened the stability of the oasis eco-environment in arid area and has restrained the sustainable development of social economy.Therefore,the monitoring of the distribution of saline land and the salinization degree,and analyzing its cause is significant for sustainable development of oasis eco-environment and social economy.This paper took Weigan-Kuqa river delta oasis located on the northern fringe of Tarim basin as an example,based on field investigation and remote sensing images data of TM,ETM and ALOS in the year of 1989,2001 and 2007 separately by using supervised classification method,analyzed the dynamic changes of saline land.【Result】In the period of 19 a from 1989 to 2007,severely salinized land area increased from 1 177.78 to 1 192.33 km2,moderately salinized land area increased 1 353.25 km2,slightly salinized land area cut down by 3.40%,and total area of saline land has an increasing tendency,with an increased area of 981.30 km2.【Conclusion】The leading factor of salinization occurrence is made by human.The increasing need for water and land resources and unreasonable utilization resulted in worsening of eco-environment,and further aggravated salinization.