东北地区50万人口以上的大城市有14座,其中100万人口以上的特大城市有沈阳、大连、鞍山、抚顺、长春、哈尔滨等6市。这些城市的工业产值占有相当大的比重,如以辽宁为例,其50万人口以上的大城市1985年工业总产值占全省的76％,这些城市都是依江而立的,因此,城市防洪是江河防洪的重要组成部分。东北地区涉及防水害的大中城市近30座。水害主要来自夏秋的大汛的暴雨 There are 14 metropolises with more than 500,000 inhabitants in northeast China. Among the megacities with over 1 million population are Shenyang, Dalian, Anshan, Fushun, Changchun and Harbin. The industrial output value of these cities accounts for a large proportion. For example, in Liaoning, for example, the gross industrial output value of large cities with more than 500,000 inhabitants accounted for 76% of the province’s total output in 1985, and these cities are all based on the river. Therefore, urban flood control Flood control is an important part of the river. Nearly 30 large and medium-sized cities in Northeast China involving water damage. Water damage mainly comes from heavy rain in summer and autumn