基于GEE的黄河三角洲地区土壤含盐量时空反演  

Spatio-temporal inversion of soil salinity in the Yellow River Delta region based on GEE

作　　者：付萍杰 补沅坤 马池杰 李晓彤 马明亮 FU Pingjie;BU Yuankun;MA Chijie;LI Xiaotong;MA Mingliang(School of Surveying and Geo-informatics,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]山东建筑大学测绘地理信息学院,山东济南250101

出　　处：《测绘通报》2024年第11期13-20,26,共9页Bulletin of Surveying and Mapping

基　　金：山东省高端人才项目支持计划(0031504);国家自然科学基金(42101388);济南市校融合发展战略工程项目(JNSX2023065);山东省高等学校“青创团队计划”(2022KJ201)。

摘　　要：本文以黄河三角洲为研究区,基于2022年遥感影像和地面实测盐分数据,提取与盐分数据相关性强的遥感光谱指数、波段反射率作为建模因子,运用多元线性回归、随机森林、BP神经网络及XGBoost回归方法,构建土壤盐分反演模型,并选择最优模型对研究区的土壤盐分含量进行了2001—2020年的长时序反演分析。结果表明:①通过相关性分析筛选出与土壤含盐量相关的8个光谱信息(CRSI、DVI、ENDVI、MSAVI、NDSI、NDVI、SI-T,近红外波段),均在P<0.01的水平上显著相关;②对比4个反演模型的预测精度,XGBoost算法具有较稳定的预测能力,对研究区土壤含盐量的反演效果最优,验证集R 2与RMSE的值分别为0.84和3.066;③根据土壤含盐量从低到高,将研究区盐渍化等级分为Ⅱ、Ⅲ、Ⅳ和Ⅴ4个等级,近20年内研究区盐渍土总面积呈下降趋势,占研究区总面积的比例降低20.7%。In this study,the Yellow River Delta is taken as the research area.Based on the remote sensing image and ground measured salt data in 2022,the remote sensing spectral index and band reflectance with strong correlation with salt data are extracted as modeling factors.Multiple linear regression,random forest,BP neural network and XGBoost regression method are used to construct soil salt inversion model,and the optimal model is selected to carry out long-term inversion analysis of soil salt content in the study area from 2001 to 2020.The results show that:①Through correlation analysis,8 spectral information(CRSI,DVI,ENDVI,MSAVI,NDSI,NDVI,SI-T,near infrared band)related to soil salt content are screened out,which are significantly correlated at the level of P<0.01.②Compared with the prediction accuracy of the four inversion models,the XGBoost algorithm has a stable prediction ability,and the inversion effect of soil salinity in the study area is the best.The values of R 2 and RMSE in the validation set are 0.84 and 3.066.③According to the soil salt content from low to high,the salinization grade of the study area is divided into four grades(Ⅱ,Ⅲ,ⅣandⅤ).In the past 20 years,the total area of saline soil in the study area showed a downward trend,reducing by 20.7%of the total area of the study area.

关 键 词：黄河三角洲 GEE 时序遥感 土壤盐渍化 XGBoost 

分 类 号：P237[天文地球—摄影测量与遥感]