Research On Sediment Distribution In Typical Sections Of Songhua River Based On Remote Sensing Technolog

Suspended sediment is one of the three elements of water color and an important influencing factor in studying the ecological environment of water bodies,primary productivity,safety of hydraulic structures,and nutrient flow.Therefore,it is valuable and meaningful to monitor the suspended sediment concentration in some typical sections of the Songhua River.This paper takes the Harbin section,Tongjiang section and Songhua Lake section of the Songhua River as the study area,uses remote sensing reflectance data and measured suspended sediment concentration data to establish a variety of different inversion models in dry season and wet season,and verifies the accuracy of these inversion models.The results are as follows:(1)After comprehensive comparison of FLAASH and sen2 cor atmospheric correction modules,it is found that the correlation between sen2 cor atmospheric correction module and suspended sediment concentration is generally higher than that of FLAASH atmospheric correction module.Among them,B2,B3,B4 and B8 have the highest correlation,which are 0.515,0.412,0.613 and 0.567 respectively.(2)After verifying the accuracy of various inversion models based on sentinel-2a,it is found that.In the dry season,the quadratic polynomial model of B8 /B4 has the highest accuracy,the fitting degree is 0.817,the root mean square error is0.0169g/l,the minimum relative error is 11.068%,and the maximum relative error is29.453%.In the wet season,the quadratic polynomial model of(B8 + B4)/(B3 + B2)has the highest accuracy,the fitting degree is 0.910,the root mean square error is0.0222g/l,the minimum relative error is 3.272%,and the maximum relative error is23.123%.(3)Songhua River is the highest River in the middle latitude of China’s seven major rivers.In recent years,the areas near the basin have actively responded to the call to promote river economy and promote the overall development of Songhua River Basin.Many large and medium-sized hydraulic structures and tourist resorts have been built.Suspended sediment is one of the three elements of water color.It is an important factor to study the water ecological environment,primary productivity,the safety of hydraulic structures and nutrient flow.Therefore,from the perspective of ecological environment,economic development and social stability,it is valuable and meaningful to monitor the suspended sediment concentration in some typical sections of Songhua River.(4)After analyzing the factors that affect the concentration of suspended sediment,it was found that hydraulic structures have a interception effect on suspended sediment.There is a positive correlation between the runoff and sediment transport in the river section.The larger the sediment transport,the higher the concentration of suspended sediment in the river section.In the surface soil of river banks,the concentration of suspended sediment in watersheds with a larger proportion of sandy soil is lower,while in watersheds with a larger proportion of clay and silt soil,the concentration of suspended sediment is higher.