48年来黄河入海水沙过程及其对流域人类活动的响应

黄河下游入海水沙现今出现急剧减少的趋势.水沙的季节性变化影响着年内的径流量、输沙量的分配情况.这种变化的影响因素有自然因素和人为因素两方面,而后者占主要地位.水沙的锐减对河口生态环境的变化有着负面影响.黄河干流已建成的大中型水库尤其是龙羊峡水库对入海水沙起着负面作用.

VARIATIONS IN THE YELLOW RIVER WATER DISCHARGE AND SEDIMENT LOAD INTO THE SEA IN THE LAST 48 YEARS AND THEIR RESPONSE TO HUMAN ACTIVITIES IN THE RIVER BASIN

In recent years, the Yellow River water discharge and sediment load into the sea had a trend of sharp reduction. The seasonal variations in water and sediment discharges affect the distributions of annual runoff and sediment discharge. The variations are affected by the natural factor and human factor with the latter playing a do-minant role. The sharp reduction of water and sediment discharges has a negative effect on the changes in the estuarine ecologic environment. The large and medium-sized reservoirs built in the river mainstream, especially the Longyangxia reservoir, have negative effects on the water discharge and sediment load into the sea.