泥沙淤积与洞庭湖调蓄量变化

本文通过实测资料分析并比较了洞庭湖八十年代和六十年代调蓄量，在相同的入湖流量和出口城陵矶水位的条件下，得到汛期高水位时八十年代调蓄量大于六十年代的认识。调蓄量增大的主要原因是由于螺山至汉口河段的大量淤积，城陵矶附近长江干流的洪水位不断抬升，造成相同水位下洞庭湖出流量大幅度减少。上述调蓄量的增大，对降低长江中游河段水位起到积极的作用，但同时加重了湖区的防洪压力。

Sediment deposition and variation of flood storage capacity in Dongting Lake

Based on the field data, the variation of flood storage capacity in Dongting Lake is investigated. It shows that the flood storage capacity in 1980's is larger than in 1960's under the conditions of the same upstream runoff and downstream water level. The sediment deposition in the reach from Luoshan to Hankou of Yangtze River is the main cause affecting the increment of storage capacity. The increase of flood storage capacity is a benefit to reduce the water level in Luoshan reach, but will intensify the flood disaster in Dongting Lake.