Extracting Water System From Landsat TM Imaging

Water System is important geography line, are often seen as terrain sketch, have some restrict on other relevance elements. The drainage network is composed of water reach and dry reach. Quickly extract linear feature of drainage network from remote sensing image, then we can obtain the characteristic parameter of river basin, judge the properties of lithology, speculated further the roughly conditions of geological structure and crustal movement. It will offer a favorable condition for data update and application in GIS.This paper consists of three parts: Carry principal component analysis on Multi-Band remote imaging for Pre-processing such as dimensionality reduction, image enhance; Semiautomatic seeds growing extracting the drainage network; Thinning and denoising based on mathematical morphology, then obtain single pixel drainage network.There have many studies on extracting linear feature of drainage network from remote sensing imaging, however, there are still many issues to be resolved. In this paper, focusing on the study of drainage network extraction. This paper through study and analysis on extracting the water and loess gulley for the recent years, study basic idea of drainage network extracting, proposed quickly extracting linear feature method.Firstly, apply principal component analysis to remove the correlation of six different bands, then obtain the principal component image which reflection evidence on drainage network, based on image features and the knowledge of drainage network, determine the growth criteria and termination rules of the seed point which manually select, growth pattern of static and dynamic, static growth ergodic whole image to extract drainage network, dynamic use the seed point for the current point to extract drainage network. Program corresponding, include the function of image enhance, filtering, regional segmentation, point growth, mathematical morphology, complete the extracting of drainage system well. Selected different region and different types of drainage network imaging to test, all of them quick extract complete drainage network.