【摘要】 根据历史记载和灾害系统分析方法,认为黄河自东汉以来确实存在相对稳定的时期。黄河水患较低是多种因素综合作用的结果,其主要原因包括3个方面:(1)由气候原因导致的黄河下游来水量的减少和由于黄土高原地区土地利用方式由农转牧导致的水土流失的减少,进而使黄河下游河水含沙量的减少,河道淤积速率低。(2)王景治理黄河和黄河下游大量湖泊沼泽的存在大大提高了黄河下游地区的防洪能力。(3)由战乱导致的华北平原人口稀疏,经济发展的脆弱性低。更多还原

【Abstract】 There is a dispute about existence of a long period from Eastern Han Dynasty to Tang Dynasty (90-870 A D) in history, when flood was rarely on the lower reaches of Yellow River. It was considered that the long period without severe flooding on the lower reaches of Yellow River during 70 -870 A D is assuredness based on the historical recordation and by using the disaster system analysis. The cause of rare flooding on the lower reaches of Yellow River was resulted from the integrated effect of multi-factors. The main causes include three factors as following. (1) The water quantity reduction of lower reaches of Yellow River results in the cold - dry climatic period, and the decrease of the loss of water and soil owing to the change of land use mode in the Loess Plateau which lead lessen of sandy quantity in the lower reaches of Yellow River. (2) Greatly improve the prevent flood ability because of the control engineerings of Yellow River and there are lots of lake and swampy in the lower reaches of Yellow River. (3) The sparse population of North China Plain was resulted from war, and conduce the lower on the social frangibility.更多还原