黄河清水沟流路水沙组合和河口三角洲发育的宏观特性

黄河清水沟流路1976～1995年期间入海水沙偏少,年际和年内变化丰枯交替,河口三角洲的冲淤变化与入海水沙大小密切相关;分析其剖面淤积形态、洲面淤积造陆情况和泥沙淤积的空间分布,表明河口三角洲发育存在着初期迅速增长、中期快速增长、后期平缓增长的宏观特性和规律,根据水沙变化与河口三角洲增长面积的定量关系以及对未来入海水沙的预估,认为清水沟流路河口三角洲的发育将继续维持平缓增长的态势.

Conditions of flow and sediment discharge, and the macro-evolution property of the delta in Qingshuigou course of the Huanghe River

The quantities of water and sediment discharged into the Huanghe River Estuary in Qingshuigou course (1976-1995) are less than those of the other three courses before 1976, and the annual and yearly variations are abundant and dry alternately, the scouring and alluviating areas of the delta are closely-related to the quantity of water --sediment into the estuary. The silting topography of the profile, the status of area growing and the alluviation distribution of the sediment discharge are analyzed, and it is found that the evolution of the Huanghe River Delta has been undergoing three period: in the primary period from 1976 to 1980 the river delta grew in a widely estuary region, in the mid-period from 1981 to 1990 the river delta grew quickly, and in the last period from 1990 to 1995 the river delta grew gently. According to the condition of water - sediment quantity in the Qinshuigou course, the area sediment analogue model is used to forecast the area growth trend of river delta in the future.