基于地图与遥感信息的大纵湖近期水域变化研究

STUDY ON RECENT WATER AREA CHANGE OF DAZONG LAKE BASED ON TOPOGRAPHICAL AND REMOTELY SENSED INFORMATION

本文选用不同年代的地形图、以及遥感图象数据等信息源，用Coreldraw软件对这些信息进行数字化，并用地理信息系统的分析方法对大纵湖的近期水域动态变化进行了初步研究。20年代与50年代间大纵湖的叠置分析表明其减少的幅度很大，达到5.7l 5km2；50年代与70年代间大纵湖的减少不明显，仅有0.267km2；70年代至90年代大纵湖减少了1.4l2km2，所以它只剩下25.201km2了。大量水利工程的修建导致上游来水减少，同时也使该地区的排水力度加大，这是20年代至50年代大纵湖减小的主要原因，80年代以后水产养殖业的发展是其变化的主要因素。

The information sources, including topographical map at different tines and remote sensing image, were selected to preliminarily investigate the dynamic variation of Dazong Lake with digitized software Coreldraw and GIS analysis method. The overlay analysis of Dazong Lake between the 1920s and the 1950s showed that it had reduced by 5.715km2,which was the maximum in the three periods; the reduction of Dazong Lake between the 1950s and the 1970s was not significant, only 0.26km2, Dazong Lake reduced by 1.412km2 from the 1970s to the 1990s, that is only 25.201km2 remained in the 1990s. The construction of many water conservancy projects resulted in the reduction of water from upper reaches, and the acceleration of drainage in Dazong lake, led to the reduction of Dazong lake between the 1920s and the 1950s. Aquaculture development was the main reason of Dazong lake change after the 1980s.