塔里木河上游地区土壤盐渍化信息提取研究

塔里木河流域气候干燥,蒸发量远大于降雨量,而且利用高矿化地表水资源灌溉,引起土壤盐渍化。选取土壤盐渍化严重的塔里木河上游地区为研究对象,在第4波段选取阈值将水体和居民地剔除,对植被指数选取阈值将非盐渍化土壤与盐渍化土壤分开,应用主成分分析和土壤指数对盐渍化土进行图像变换,得到盐渍化土的图像特征,通过判别函数值的大小对光谱特征进行信息量排序,取信息量最丰富的前3种光谱特征。在此基础上结合地下水埋深、矿化度等地理信息对土壤盐渍化信息进行综合提取和分类,提高了土壤盐渍化的分类精度,可快速查明塔里木河流域土壤盐渍化的现状,对加快塔里木河流域综合治理,恢复塔里木河上游绿色走廊具有重要意义。

THE INFORMATION EXTRACTION STUDY OF SOIL SALINIZATION IN UPPER TARIM RIVER

The climate in Tarim river valley is dry.And the evaporation far exceeds rainfall there.And that using high salinity surface water to irrigating caused soil salinization in this area.Choosing upper Tarim river area where soil salinization is strictness as study object,setting the proper threshold on band 4 to reject water body and settlement place,choosing the right threshold for vegetation index image to separate saline-alkali land and non-saline-alkali land,applying principal component analysis and soil index to transform the image,then obtaining the image characteristics of soil salinization.Sorting the spectral characteristics according to the result of discriminant,acquiring the first 3 spectral characteristics which containing richest amount of information.On this basis,combining the groundwater depth,salinity,and other geographic information to extracting and classing the soil salinization information,increased the classification accuracy of soil salinization.It could rapidly identifying the status quo of Tarim river valley,which has great significance in speeding up the Tarim river comprehensive management and restoring the green corridor of the upper reaches of Tarim River.