Evaluating the hydrological effects of the Three Gorges Reservoir based on a large-scale coupled hydrological-hydrodynamic-dam operation model

Understanding the hydrological effects of the Three Gorges Dam operation in the entire reservoir area is significant to achieving optimal dam regulation. In this paper, a large-scale coupled hydrological-hydrodynamic-dam operation model is developed to comprehensively evaluate the hydrological effects of the river-type Three Gorges Reservoir. The results show that the coupled model is effective for hydrological, hydrodynamic regime and hydropower simulations in the reservoir area. Dam operation could have a notable positive effect on flood control and could reduce the maximum daily flood peak by up to 26.2%. It also contributes a large amount of hydropower, approximately 94.27 TWh/year, and a water supply increase for the downstream area of up to 22% during the dry season. In the flood season, the water level at Cuntan would increase under the condition that the water level of the dam is higher than approximately 158 m due to dam operation. In the dry season, attention should be paid to the low flow velocity near the dam in the reservoir area.

Hydrological Problem during Urbanization Process

With the rapid economic and social development, China is in rapid development period of urbanization now. Urbanization is an inevitable trend of mankind development, and is also a necessary stage of a country moving toward modernization. The rapid development of urbanization has a major impact on urban hydrology. Urban hydrologic environment, hydrologic element, water resources and water quality were discussed in the pa- per. Based on the analysis of urban hydrological effect, from the angles of subject development and application, corresponding countermeasures and outlook of the urban hydrology problem were put forward. The research can provide support for reasonably planning and designing urban flood control and drainage systems to promote urban environment-friendly development, having certain practical significance.

流域植被对水量平衡影响的模拟研究(英文)

By means of SSiB/TOPMODEL model which was the coupled model of simplified simple biosphere model(SSiB)and TOPMODEL,the sensitivity experiment of basin water balance was carried out in Suomo River basin covered by five vegetations,and the effects of vegetation on water balance were analyzed.The results showed that vegetation cover increased canopy transpiration and interception but decreased soil evaporation.The two contrary net effects determined the basin runoff affected by the hydrological effect of vegetation.For the five simulated vegetations,basin evaporation went down but basin runoff went up compared with bare land.When basin was covered by grass,total basin evaporation was highest(1.220 5 mm/d),and total basin runoff was the lowest(0.658 7 mm/d).When deciduous needle-leaf forest covered the basin,total basin evaporation was minimum(1.025 mm/d),while total basin runoff was maximum(0.854 4 mm/d).Transpiration and canopy interception reached maximum values of 0.383 and 0.489 mm/d when covering evergreen coniferous forest.For soil evaporation,it was highest with grass(0.799 mm/d)and lowest with evergreen coniferous forest(0.243 mm/d).

The hydrological effect between Jingjiang River and Dongting Lake during the initial period of Three Gorges Project operation

Based on the measured hydrological data from 1951 to 2008, the chain hydrological effect between Jingjiang River and Dongting Lake is analyzed by comparative method after the Three Gorges Project operation. The result indicates that 1） the scouring amount in Jing- jiang River made up 78.9% of the total from Yichang to Chenglingji, and its average scouring intensity was higher than the latter; 2） the water and sand diversion rates at the three outlets of the Jingjiang River were reduced by 2.33% and 2.78% separately; 3） the proportion of multi-year average runoff and sediment through the three outlets in the total into the Dongting Lake decreased by 7.7% and 24.4% respectively; 4） in Dongting Lake, the speed of sediment accumulation was lowered by 26.7%, in flood season, the runoff amount was 20.2% less than the multi-year average value, leading to seasonal scarcity of water year by year. The former prolonged the lake life, while the latter induced droughts in summer and fall in successive years, shortage of drinking and industrial water, shipping insecurity, as well as ecological problems such as decrease of birds and quick increase of Microtus fortis; 5） The multi-year average values of sediment and flood transporting capacity at the lake outlet were respec- tively increased by 26.6% and 3.7%, the adapt to the new change of the river-lake embankments were protected effectively. Then, to relation, some suggestions were put forward, such as optimizing further operation program of the Three Gorges Reservoir, reexamining the idea of river and lake regulation, and maintaining connection of the river and the lake.