【摘要】 通过对洞庭湖1951￣1998年径流泥沙演变过程及其驱动力的全面分析表明,径流泥沙关系密切,其相关系数r=0.9013。年径流量、年输沙量总体均呈同步减少趋势,在演变过程中表现出明显的阶段性。由于湘、资、沅、澧四水流域产水量大,森林覆盖率达52%以上,连年兴建的水利工程及工农业、生活用水量的增加,未能对四水河流水文特征产生根本性的影响,其入湖径流泥沙基本处于稳定状态,故没有对湖泊径流泥沙的演变造成深刻影响。而由长江中游河段的调弦口堵口,下荆江系统裁弯和葛洲坝截流所引起的3次江湖水沙关系调整,即是导致洞庭湖径流泥沙缓减速减的主动因子。更多还原

【Abstract】 Some conclusions drawn from multianalysis of the evolution process of annual runoff & sediment and the driving forces in the Dongting Lake from 1951 t o 1998 are as follows: Runoff and sediment connect with each other closely and t he related modulus is 0.9013. Annual runoff volume and annual sediment discharge as a whole take on a synchronously-decreasing trend, and the evolution process is characterized by obvious stages. Because the major catchments of Xiangshui, Z ishui, Yuanshui and Lishui drainage basins and the high forest-covering-rate abo ve 52%, the newly built water conservance projects in recent years and the incre ase of industrial, agricultural and domestic water consumption cannot exert fund amental influence on the hydrological characteristics of the four rivers and the runoff and sediment flowing into the lake are basically stable, so they do not have profound effect on the runoff and sediment in the lake. The three-time adju stment of of water-sand relations of the rivers and the lake resulting from the pluging up of Tiaoxian bayou on the midlle reaches of the Yangtze River, the cur ve-cuttings in the lower Jingjiang River system and the flow-cutting at Gezhouba dam, however, become the main factor leading to the deceleration of the runoff and sediment in the Dongting Lake.更多还原