我们主要河流的中下游有一百万平方公里的平原。这个平原本为河流冲积及每年洪泛地区。经过几千年人民的劳动,依靠了堤防的保护,逐渐成为农业生产最富饶、人口最密集的区域。全国六亿人口几有半数集中于此占全国面积十分之一的平原地带,包括了我们大多数的主要城市。很明显地,这样长期与水争地发展的结果,生产与洪水的矛盾逐渐尖锐。尤其长江的中下游,农业生产以秋季收获的水稻为主要作物而秋季亦正是洪水盛涨的时期,因此情况又为突出。长江灾害的统计就说明了这个 There are one million square kilometers of plains in the middle and lower reaches of our major rivers. This plain was originally an alluvial river and flooding area every year. After thousands of years of people’s labor, relying on the protection of embankments, it has gradually become the most productive and populous region in agricultural production. Half of the country’s 600 million people are concentrated in the plains that make up one tenth of the national area, including most of our major cities. Obviously, as a result of this long-term struggle against water, the conflict between production and floods has become increasingly acute. In particular, in the middle and lower reaches of the Yangtze River, agricultural production is dominated by rice harvested in the fall, and autumn is just the time for a flood to rise. As a result, the situation is also prominent. The statistics of the disaster on the Yangtze River illustrate this