Remote Sensing Based On The Depth Of The North Channel Erosion And Deposition Of Analysis

There are three-order bifurcations and four outlets into the sea in the Yangtze Estuary, and the North Channel is one of the second order bifurcations, it is one of the main channels into the sea. There is a little study for the North Channel in the past 20 years. With North Channel has presented more effect since past several years, we need to know more about river runoff, sediment and estuary channel process in North Channel. Based on the important item of nation natural science fund "The effects and countermeasures of the water transfer projects etc. on the estuarine environment in the Yangtze Estuary" (50339010) , the paper research main channel of North Channel with water data and underwater terrain. For lack of charts in the 90s ,the study retrieve the water-depth map of 1997 using water-depth retrieval models.First, the paper expatiate theory and method of water depth remote sensing., transact images in advance. The paper get non-linear retrieval model to retrieve the water-depth map and there are some cognitions after analyzing: the method can be used to another image, the result presents that extract water depth by this method is feasible and universal.Second, the analysis for the changes of the cross sections, contours, erosion-siltation and volumes of river channel were made according to the tool of GIS and DEM. the process of the North Channel morphology was illustrated and the reason of the evolution was analyzed summarily. Along with the decreasing of sediment discharging, the underwater bar are eroding and the channel volume is growing in North Channel; the influence of the flood and the hydro-engineering projects in the drainage basin such as Three-Gorges Project and the South-to-North Water Transfer Project is important to the evolution of North Channel.