Study On Suspended Sediment Distribution In Zhoushan Sea Area Based On Remote Sensing Technology

Affected by the incoming sand of the Qiantang River and the Yangtze River,the water suspension sediment concentration is high in Zhoushan.Suspended sediment is one of the important water quality parameters in case-? water.Suspended sediment concentration directly affects water optical information such as water color and turbidity,thereby the ecological environment of aquatic life,such as primary productivity,nutritional mobility,marine biodiversity,etc.The process of suspended matter migration directly affects the sediment deposition in coastal and near-shore areas,and will affect coastal engineering,port construction,and channel operations.Zhoushan is rich in biological and waterway resources.Therefore,it is of great significance to study the suspended sediment concentration and spatial-temporal distribution pattern in Zhoushan.In this paper,the Zhoushan sea area is used as a research area,use the field measured spectral data and suspended sediment concentration data,build multiple remote sensing inversion models for different waveband combinations of suspended sediment concentration in Zhoushan sea area and check its accuracy.Finally,we select the best inversion relation of suspended sediment concentration in Zhoushan sea area.Applying this relationship with Landsat8 remote sensing data in Zhoushan to retrieve suspended sediment concentration.Briefly analyze the spatial-temporal distribution characteristics and the influencing factors of suspended sediment concentration.The result is as follows:1.After comprehensive analysis and verification of various inversion models based on the Landsat8 band range,it was found that the quadratic polynomial model constructed with the ratio model B4 / B3 as the influencing factor can better reflect the relationship between the remote sensing reflectance and suspended sediment concentration.The average relative error is 23.21% and the root mean square error is 0.0691 g / L.2.The spatial and temporal distribution characteristics of suspended sediment in Zhoushan sea area are: In terms of seasonal distribution,the concentration of suspended sediment in winter is significantly higher than that in summer.It shows the phenomenon of "higher in winter and lower in summer,and spring and autumn are between winter and summer".The average suspended sediment concentration in winter is about 0.3g / L and in summer is only about 0.1g / L.In terms of spatial distribution,the suspended sediment concentration on the west side(nearshore)of Zhoushan Sea area is significantly higher than that on the east side(offshore),and the suspended sediment concentration around the island is also higher than that in open water areas,it shows a pattern of "west is higher and east is lower,near shore is higher and lower in sea".3.The tidal have a significant effect on the distribution of suspended sediment in the Zhoushan sea area in a short time.Runoff sediment transport has significant interannual changes in suspended sediment concentration in the Zhoushan sea area,and there is a clear positive correlation between the both.The archipelago topography in Zhoushan sea area has played a role in screening and spreading the sediments of the Yangtze River and Qiantang River.