Study On Soil Salinity In The Yellow River Delta Based On Remote Sensing

Soil salinization is one of the major types of land degradation.As a global resource issue and ecological environment issue,it is the main cause of agricultural output decline,soil erosion,deterioration of the ecological environment,and global warming,especially in the In arid,semi-arid,and coastal alluvial plains,soil salinization is more serious and the negative impact is even greater.On the regional scale,especially the effective monitoring of soil salinity distribution and temporal and spatial dynamic changes in coastal sea-water dip saline areas is of great significance for soil salinization treatment and ecological environment protection.Remote sensing technology,with its large-scale and high temporal resolution,has become the most important way to dynamically monitor soil salinity in large areas.In this paper,the Yellow River Delta is selected as the research area,Landsat TM/OLI remote sensing data and the corresponding ground measured soil sampling point salinity data are used as data sources,and the optimal factors for constructing soil salinization remote sensing prediction model are selected and selected.Based on the digital elevation model data,a soil salinity inversion model based on the surface spectral reflectance,surface salinity index,and surface vegetation index was constructed,and the accuracy of the model was verified based on the measured soil salinity.Finally,based on the highest precision integrated model for inversion of salt content,this paper retrieved the soil salinity in the study area on Oct.26,2003,Oct.26,and Oct.27,2015,and integrated inversion.The results analyzed the temporal and spatial dynamic distribution of soil salinity in the study area.The main results are as follows:?1?Through a stepwise multiple linear regression of the variables of the constructed model,the final inversion model for soil salinity is:S=1.347X₁³-1.684X₂³-0.254ln?X₃?-1.856X₄-.0164X₅-0.039X₆+3.114?2?Using the remote sensing inversion model of soil salinity in the Yellow River Delta to predict the salinity of TM images in 2008,TM images in 2009,and OIL images in 2015,the distribution of soil salinity in three periods was obtained.According to the salinization soil grading standard,the distribution map of soil salt content in the study area was obtained,and the temporal and spatial dynamic changes of soil salinity in the study area were statistically analyzed,and the dynamic monitoring of soil salinity on the regional scale was realized.?3?The degree and distribution pattern of soil salinization in the Yellow River Delta region have changed significantly over the past decade or more.In the time range,the soil salt content showed a trend of increasing first and then decreasing,and the space showed a decreasing trend along the coastline to the interior.