Simulation Of 3D Terrain And Water Dynamic Routing Of Qinghai Lake

To break the limitation of space, it is a natural trend to develop 2d GIS into 3dGIS.With the development of 2D GIS and visualization technology ,more and moreconcern about 3d GIS is got. Current GIS is not able to deal with some problemsabout real 3d, and prevents GIS from going farther in many fields, so we must domore studies on 3d GIS and multi-terrain GIS. Beginning with bottom program, thedissertation presents water routing based on 3d terrain model and visualization ofthe 3d terrain as well as natural scene on computer through GIS-VR technology .Itis main parts of my dissertation to construct 3d terrain model and visualize 3dterrain and dynamic water routing.To model 3d terrain is the base of the system. the dissertation begains with themain problems in modeling and visualizing 3d terrain ,and analyzes the mainmethods to model 3d terrain .By comparing advantages and disadvanges of regularreseau with anomalistic triangular reseau,I adopt regular reseau so as to meet thedemand of modelling 3d terrain.By means of contour data carried out by Arc/info,thesystem converts data into Delaunay firsttly,interpolates to Delaunay secondly,andthanslates DEM data into regular reseau data at last.Studying of 3d terrain visualization technology is essential to demonstrate 3dterrain.I use technique of protracting graphics in OpenGL to realize visualization ofthe 3d terrain in this program. Visual C++ is the programming platform. Datapretreatment,illumination parameter,projection fashion and texture mapping arepivotal technique to visualize + the 3d terrain.Arithmetic study of water routing is the theoritical base of realizing waterdynamic routing .Designing from space-time adaptive model ,selecting boundarysearching algorithm , ignoring secondary factors, and simplifying boundaryconditions ,the program uses breadth-first search and adds boundary controlconditions to it ,which provide a availiable solution to the problem.According to the theory, This dissertation takes qinghai lake as an example ,andpresents perfectly 3d terrain of Qinghai lake and water dynamic routing with thesupport of GIS, VR, 3d terrain mobiling and visualization technology.