黄河是世界闻名的多沙性河流,历史时期就不断淤积、决口改道,且淤积速度不断加快,决口改道的频率也在不断增加。黄河下游地上河的发展和演变是自然因素和人类活动综合作用的结果。历史时期流域内人口的增加、耕作方式的改变及其对植被造成的破坏都对中游地区侵蚀的加剧、来沙的增加,以及下游地区河道的淤积及决口改道的发生带来不同程度的影响。

It is well known that the Yellow River is a very famous river with much sediment in the world. Deposition of the river bed as well as the breach and diversion of the river course happened frequently through the whole historical period, so that the accumulation of North China Plain has been getting more faster since Quaternary period. According to field investigations, the behavior of the lower Yellow River before Tongwaxiang breach happened was basically the same as that of the modern lower Yellow River. The average accumulating ratio of the lower Yellow River for the riverbed was 6 5 cm/a during 1855~1982, not including 1938~1947 when the Yellow River took the southern course and 7 7 cm/a for the floodplain.\;It is shown from statistical data that the frequency of river breach and diversion in the Lower Yellow River has been faster. The frequency of river breach and diversion in the Lower Yellow River wasn’t very high before the period from 602 B C to A D 907, but increased more obviously during Wudai Dynasty to Song and Yuan Dynasty than before, almost one time of breach per two years. In order to guarantee water transport of grain to the capital during Ming Dynasty, the northern levee was reinforced, but the southern one was not, so that the breach frequency of this period was doubled compard with Song and Yuan Dynasty. On average, there are three times of breaches per two years during Qing Dynasty to Republic of China.\;The accelerated deposition and the increasing frequency of breach and diversion in the Lower Yellow River are caused by the complex action of natural factors and human activities. With the increase of population, the change of cultivation types and the destroying of vegetation in the drainage area of the Middle Yellow River during the historical period, soil erosion was greatly intensified and the oncoming sediment to the Lower Yellow River increased, so that deposition, breach and diversion happened frequently in the lower Yellow River.