Research And Implementation Of Dynamic Visualization To Gully Headward Erosion Process Using Point Cloud Data

With the development of computer technology, Traditional Surveying and Mapping Technology is becoming more and more perfect, however, for the terrains that are complex and unreachable, the traditional surveying and mapping technology is unable to meet the needs of measurement. To fulfill the needs of social and economic development, Three Dimensional Laser Scanning Technology becomes a new change in modern surveying and mapping since the advent of the GPS. With incomparable advantages over traditional measurement methods, Three Dimensional Laser Scanning Technology is widely used in various fields, such as landslide monitoring, ancient architecture protection, topographic survey, three dimensional city modeling, etc., and obtains satisfactory results, especially in complex terrain measurement. Three dimensional laser scanning technology shows greater advantages with non-contact measurement and automation means. Combining the dynamic visualization technology, it vividly reproduces the formation process of complex terrain. Based on the understanding of a large number of three dimensional laser scanning documents and visualization technology researches, the thesis targets at dealing with the point cloud data with three-dimensional coordinate information and constructing the spatial-temporal data model, and finally realizes dynamic visualization process under the ArcGIS10.0software platform, which involves point cloud data acquired by three dimensional laser scanning technology during erosion process of the simulation gully in the experimental field. The main content of this thesis is as following:(1) The thesis has introduced the types and application field of the three dimensional laser scanners, and also analyzed their working principles and advantages. Besides, the point cloud data produced by laser scanning have been preprocessed, such as point cloud registration, noise eliminating, etc.(2) The paper regards erosion condition in experimental simulation gully as research object, employing three-dimensional laser scanner to get point cloud data and establishing the DEM space model. Then, time information will be brought into the DEM model to construct temporal data model, and finally to fulfill dynamically visual expression of gully headward erosion process.(3) Based on ArcSecne10.0software platform, the paper is supposed to realize the dynamic visualization of erosion state in the experimental field during different time. By simulation of change process of the gully headward erosion, the thesis has also analyzed its visualization results.(4)Variables of Erosion volume in the experimental field on gully erosion process has been performed data analysis and graphics display. By studying erosion intensity during different time and contrasting erosion intensity of the adjacent time, the field erosion process which changes over time will be reproduced. It is hoped that the research will give guidance and decision basis for the local gully headward erosion mechanism study.The thesis takes the simulation gully headward erosion process in experimental field as the research object. Under the help of ArcGIS10.0software platform, the thesis has realized dynamic demonstration of field erosion process, and also fulfilled a quantitative analysis of volume change of erosion. It is hoped that this paper can shed some light on the researches of gully headward erosion mechanism.