新疆焉耆县土地盐渍化遥感监测

Land salinization monitoring with remote sensing on Yanqi County,Xinjiang

土地盐渍化不仅会造成地表土壤资源的破坏和农业生产的巨大损失,而且对干旱区绿洲的生态安全也构成了极大威胁,已成为一个全球性的环境(土地)退化问题。研究土地盐渍化动态演化过程及其空间分布特征,有助于了解土地盐渍化变化规律与发展趋势,对于干旱区的粮食生产安全及经济发展无疑具有重要意义。利用遥感和GIS技术,以新疆焉耆县为例,基于土地利用现状图和1976、1994和2009年的MSS、TM、ETM遥感影像,系统分析了区域土地盐渍化的动态演化过程和空间分布特征。研究结果表明,1976-2009年间,尽管焉耆县的土地利用类型未发生显著变化,但土地盐碱化的面积却呈现显著增长趋势,并已达到研究区面积的8.85%;研究时段内,盐碱化持续加重区域的面积比例相对较高,盐碱沼泽和重度盐碱土地在研究区所占面积比例分别增加了2.97%和1.31%,这表明焉耆县土地盐碱化程度发展较快,今后需改善灌溉及排水方式,合理利用地下水。

As land salinization can lead a great threat for agricultural production to the degradation of physical and chemical features of soil resources, it is and regional ecological security, especially in arid environments. It can be seen as one of the key issues in global environmental or land degradation. With the application of remote sensing and geographical information system, the dynamics of land salinization can been monitored and predicted, which is of great importance to the ecological security and economic development in the arid oasis. Taking Yanqi County, Xinjiang,China, as a case, based on the land-use maps and remote sensing images in 1976, 1994 and 2009, the paper analyzed the temporal-spatial process of land use change and land sa/inization dynamics. The results showed that, from 1976 to 2009, there was not significant change of land use patterns in the study area with a little increase of cultivated land and decrease of grassland. However, the total area of salinized land was growing continously, which is about 8.85 % in 2009. Furthermore, the area proportion of salinized land in the moderate and severe levels grew excessively. The results also showed that, the area proportion of intensifying salinized land in Yanqi County was also growing, which indicated the serious threat of land salinization to arid environment. In 1976 - 2009, non-salinization land accounted for 87.99% of the whole county, the salinized land keeping the same degree of moderate or severe was 0.3%. And intensifying and weakening salinized land was 8, 25% and 3.16%, respectively. The case study showed that both remote sensing and GIS technology are a great help to the monitoring of land salinization in regional scale.