The Study About The Algorithm Of Drinage Extracting Based On Delaunay Triangulated Irregular Network

Grid DEM is analysis digital elevation model,commonly used in the field of hydrologic,currently,program algorithm used in almost all geographic information system software and specialized hydrological analysis software during their development process are based in digital elevation model.Triangulated Irregular Network(TIN)is a manifestation of the digital elevation model(DEM)form.TIN can simulate variable resolution and high-precision terrain,providing better than the traditional grid topographic expression of accuracy,and its unique nature of vector better express river structure and basin topology.Based on these advantages and features,select TIN as hydrologic analysis algorithm gradually increased.After TIN data collected in the field,need for pre-processing operations,the result will affect the degree of real analog TIN surface,which determines the degree of accuracy of hydrological analysis algorithm.These points will be discussed in this article:(1)Various data types of DEM are studied,and the advantages and disadvantages of DEM data of vector,grid and irregular triangulation are analyzed.(2)The related concepts of watershed and digital watershed extraction are introduced,and the algorithm of digital watershed analysis based on DEM is studied,and the difference between it and D-TIN digital basin is discussed.(3)The D-TIN related construction algorithm is studied,and the data structure of D-TIN is designed according to the topological structure of river network.(4)Describes the topological data structure of river network based on constrained D-TIN watershed,discusses the convergence characteristics of triangle edge in TIN,and gives the corresponding rule of judgment.Finally,the river network classification algorithm based on TIN,The method of river network tracking based on D-TIN node and D-TIN accumulation method are used to describe and compare the two methods,and the correlation between the two methods is also discussed.The data structure of the D-TIN digital basin analysis of the data generated by various processes such as triangular surface flow,the Department of water storage side.(5)Based on the development platform of Viual Studio2012 and GDI + computer graphics tools,the system design and development are carried out,and the experiment is carried out on the system.