黄河三角洲盐碱地动态变化遥感监测

REMOTE SENSING DETECTION OF DYNAMIC VARIATION OF THE SALINE LAND IN THE YELLOW RIVER DELTA

运用多期陆地卫星图像数据,结合野外调查及采样分析,对黄河三角洲近15a来盐碱地的动态变化进行了监测。研究区内发现盐碱地面积呈不断扩大趋势,不同类型的盐碱地变化不同:轻盐碱地不断增多,重盐碱地逐渐减少,光板地先增后减。盐碱地数量方面的增减并没有对盐碱地在不同土地类型中的空间分布格局产生太大影响。

Land salinization is a dynamic phenomenon or process. With the annual and seasonal variation of the groundwater table, the nature, extension, magnitude and spatial distribution of the saline land are changing from time to time. The grasp of the up-to-date and reliable information on the saline land is a prerequisite for land reclamation and regional sustainable development. For the purpose of providing a generalized view of a fairly large area, remote sensing is widely used in saline land survey and dynamic study. Three groups of Landsat data were selected for the study of saline land dynamics during the past 15 years in the Yellow River Delta. Based on repeated field survey and soil sample analysis, an integrated classification method was developed for the extraction of information about saline lands. The study shows that, from 1987 to 2000, the trend of land salinization was rapidly accelerated: light saline land greatly increased; strong saline land gradually decreased; barren saline land increased from 1987 to 1996 and then decreased. The spatial structure of saline land distribution in such 6 types of landforms as terrace uplands, present flood plain, abandoned river courses, embanked former back swamps, isolated depressions and salt marshes & tidal flats in 2000 was almost the same as that in 1987.