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土壤盐渍化是干旱半干旱地区土地退化的主要原因之一,给当地生态系统和社会经济的可持续发展带来了严重的威胁,而对盐渍化空间分布信息的提取是治理盐渍化的基础。因此,选取生态脆弱区渭—库绿洲为研究区,利用2014年7月19日GF-1多光谱影像数据,提取光谱指数及波段信息,结合实际采样点的土壤表层电导率数据(0~10 cm),采用偏最小二乘回归模型(partial least squares regression,PLSR)对土壤盐渍化进行模拟,并对研究区盐渍化分布进行模拟和评估。结果表明:实测土壤表层电导率与光谱指数相关性较好;利用PLSR对渭—库绿洲土壤表层盐渍信息建模,对土壤盐渍化信息提取效果较好,精度较高;充分利用了GF-1影像包含的信息,提高了高分辨率遥感影像盐渍化信息提取的精度;非盐渍化和轻度盐渍化面积分别占总面积的42.88%和17.16%,绿洲中部偏东及东南区域,盐渍化现象稍弱,可成为今后绿洲扩张的重点方向;而中度盐渍化、重度盐渍化和盐土面积分别占总面积的29.51%、8.57%和1.88%,绿洲北部/西部及西南方向的重度盐渍化区域紧挨绿洲区域,已严重威胁了绿洲经济的健康发展,亟待治理。
Soil salinization is one of the main causes of land degradation in arid and semi-arid regions, which poses a serious threat to the sustainable development of local ecosystems and socio-economy. However, the extraction of salinization spatial distribution information is the key to salinization Foundation. Therefore, we selected the Wei-Ku reservoir oasis which is the ecologically fragile area as the research area. Based on the GF-1 multispectral image data of July 19, 2014, the spectral index and band information were extracted. Based on the actual surface soil conductivity data (0-10 cm). Soil salinization was simulated by partial least squares regression (PLSR), and the salinization distribution in the study area was simulated and evaluated. The results showed that the conductivity of surface soil was related well with the spectral index. Using PLSR to model the surface soil salinization information of the Wei-library oasis, the soil salinization information extraction effect was better and the accuracy was higher. The GF -1 images, which improves the accuracy of salinization information extraction of high resolution remote sensing images. The areas of non-salinization and mild salinization account for 42.88% and 17.16% of the total area, respectively, and the middle and the southeast of the oasis The weaker salinization and salinization of the oasis can be the key direction for the expansion of the oasis in the future. The moderate salinization, severe salinization and salinization area account for 29.51%, 8.57% and 1.88% of the total area respectively. The northern / western oasis And the severe salinization area in southwest direction close to the oasis area have seriously threatened the healthy development of the oasis economy and are in urgent need of governance.