1、问题的提出1.1鸭绿江西水道的历史沿革。上世纪三十年代以前,西水道是鸭绿江船舶出海的主要通道。三十年代以后,因上游大水库建成蓄水,后来朝方在黄金坪建设丁坝群,水流挑向对岸座草岛一侧,以致西水道上口逐渐淤塞。从此,西水道淤积越来越大,从1977年至2006年4月几份卫星遥? 1, the question raised 1.1 The history of the Yalu River Waterway. Before the thirties of the last century, the West Waterway was the main channel for the ships to go to the Yalu River. Since the 1930s, due to the construction of water storage in the upstream large reservoirs, the DPRK later built the Dingba Group at Huangjinping and the water flow toward the Sado Island side of the other bank led to the gradual build-up of the West Waterway. Since then, the West Channel silting more and more, from 1977 to April 2006 several satellite remote?