河道演变的遥感分析研究——以北江下游为例

以近30 a来共7个时相的MSS、TM遥感影像和相关地区的1︰5万地形图作为数据源，在建立遥感识别标志和影像特征的基础上 ，对北江下游河岸变迁、洲滩和河道演变进行了分析研究。结果表明，在1975~2002年间，北江下游河道具有明显演变过程，岸、滩 冲淤变化明显，部分地区发生淤积。在获取河道横向演变特性的基础上，对比该时段内北江下游河道纵向演变情况得出： 河道的纵 向变形影响横向变形，总体变化两者成反比关系，河势向着稳定的趋势发展。

A RIVERWAY EVOLUTION ANALYSIS BASED ON REMOTE SENSING TECHNIQUE: A CASE STUDY OF THE LOWER REACHES OF THE BEIJIANG RIVER

In the past thirty years, the coastwise change has been very obvious in the lower reaches of the Beijiang River. With the development of economy, the riverway environment has changed tempestuously, but the mastery of the change regularity is very difficult on the basis of traditional measures. With the advantages of macroscopic, dynamic and systematic researches, the RS technology can be used to study the characteristics of riverway evolution form the view of spanning a historical period of time. Using MSS and TM as the data source including 7 periods in the past thirty years and the 1︰50000 topographic map, the authors studied the flux of the riverside, the evolution of the bottomland and riverway by using 3S and on the basis of RS recognition symbols and characteristics of the image. According to the 3S analysis of the data available between 1975 and 2002, the riverway experienced an obvious evolutionary process, the bank and bottomland changed distinctly, and part of the area was filled up. According to the characteristics of the transverse evolution of the riverway relative to the longitudinal evolution in this period，it is concluded that the longitudinal distortion of the riverway affected the transverse distortion, i.e., there exists an inverse variation relationship between the transverse distortion and the longitudinal distortion. The development trend of the riverway seems to become increasingly steady.