Application Of GIS Technologies In Analysis On Channel Scouring And Siltation

G1S is a system of computer software, hardware and data, and personnel to help manipulate, analyze and present information that is tied to a spatial location. Many governments and large organizations use GIS because of the astonishing diversity of information types that can be mapped and analyzed-these range from population demographics, to health statistics and epidemiology, utility and transportation networks, flood protection zones, animal migration routes, crime patterns, historical battlefields, sales and marketing trends, disaster destruction areas, and much more.Spatial representation is critical to problem solving, but GIS currently excels the predictive and related analytical capabilities necessary to examine complex problems at least to some extent.The Digital Elevation Models(DEM) are increasingly becoming the focus of attention within the larger realm of digital topographic data. The quality and caliber if DEM has been extremely valuable in the hydrological applications. DEM are used in number of sub-domains in hydrology. The DEM have proved to be very efficient in extracting the hydrological data from the DEM by analysing different topographical attributes (elevation, slope, aspect, relief, curvatures) for modeling purposes. There are number of models developed which has been useful individually and combined applications in various combinations. DEM have potentially proved to be a valuable tool for the topographic parameterization of hydrological models especially for river analysis.In the page,the main procedure and concrete method for establishment of 3D surface of channel topography by using GIS and for calculation and analysis of channel storage and changes in scouring and siltation are presented. Based on the powerful GIS software ,which can be used as data input, image visualization, map analysis and computing and map output, the charts of the north channel of the Yangtze River estuary from 1958 to 20001 are digitalized. The grid maps and digital erosion and deposition variation maps of the riverbed are obtained, the probablelocationand depth of the silting are forecasted.The method has obvious advantages of higher calculation accuracy, visualized channelmorphology and distinct capability of spatial analysis of scouring and siltation locations. Therefore, the method has not only higher in theory value, but important in practice, thus it will have huge value in generalizing.