基于多光谱影像的干旱区绿洲耕层土壤盐分估算  

Estimation of soil salinity in cultivated layers of oasis in arid areas based on multispectral images

作　　者：边慧芹 王雪梅[1,2] BIAN Huiqin;WANG Xuemei(College of Geography Science and Tourism,Xinjiang Normal University,Urumqi 830054;Xinjiang Laboratory of Lake Environment and Resources in Arid Zone,Xinjiang Uygur Autonomous Region Key Laboratory,Urumqi 830054,China)

机构地区：[1]新疆师范大学地理科学与旅游学院,乌鲁木齐830054 [2]新疆维吾尔自治区重点实验室“新疆干旱区湖泊环境与资源实验室”,乌鲁木齐830054

出　　处：《干旱区资源与环境》2022年第5期110-118,共9页Journal of Arid Land Resources and Environment

基　　金：新疆维吾尔自治区自然科学基金(2020D01A79);国家自然科学基金(41561051);新疆维吾尔自治区重点实验室招标课题(XJNUSYS2019A14)资助。

摘　　要：土壤盐分的遥感反演对干旱区绿洲土壤盐渍化动态监测具有重要意义。基于2007和2019年的Landsat ETM/OLI影像与实地调查数据,采用特征空间、多元逐步回归与偏最小二乘回归对新疆渭干河-库车河三角洲绿洲耕层土壤盐分进行空间反演。结果表明:光谱指数的非线性数学变换将有助于提高反演模型的估测精度,对土壤盐分具有表征作用;与特征空间和多元逐步回归模型相比,综合植被指数与盐分指数优化的偏最小二乘回归模型对土壤盐分具有更高的估测精度和较强的稳定性;2007-2019年间,非盐渍地以年均1.346%的增长速率沿绿洲边缘向外围扩张,受自然因素与人类活动的影响,中度及重度盐渍地下降速率较快,面积占比分别由19.774%和12.991%降低至16.811%和11.231%。研究区土壤盐渍化现象虽有好转,但仍是威胁当地农业可持续发展的重要生态环境问题。The remote sensing inversion of soil salinity is of great significance to the dynamic monitoring of soil salinization in arid oasis.Based on Landsat ETM/OLI imagery and field survey data in 2007 and 2019,feature space,multiple stepwise regression and partial least square regression were used to spatially invert the soil salinity in the cultivated layer of the Weigan-Kuqa river delta oasis,Xinjiang.The results showed that the nonlinear mathematical transformation of the spectral index is helpful to improve the estimation accuracy of the inversion model,and has a characterizing effect on soil salinity.Compared with feature space and multiple stepwise regression models,the partial least squares regression model optimized by comprehensive vegetation index and salinity index has higher estimation accuracy and stronger stability for soil salinity.From 2007 to 2019,non-salted land expanded along the edge of the oasis at an average annual growth rate of 1.346%.Affected by natural factors and human activities,moderately and severely saline soils had declined at a faster rate,and the area percentages had decreased from 19.774%and 12.991%to 16.811%and 11.231%,respectively.Although the soil salinization in study area has improved,there is still important ecological environmental problem that threatens the sustainable development of local agriculture.

关 键 词：土壤盐分反演 特征空间 多元逐步回归 偏最小二乘回归 渭干河-库车河三角洲绿洲 

分 类 号：P935.1[天文地球—自然地理学] TP79[自动化与计算机技术—检测技术与自动化装置]