Advanced Materials Research Vols. 955-959

Abstract: Based on the math model and comparative analysis, the change of hydrological regime and water quality in the Han River from the site of Baihe Hydropower Station to Gushan Hydropower Station caused by the dammed water of hydropower station and the regulation effect of reservoir is studied herein. The typical days in the wet season and the dry season in the dry year were selected as the study period in which the changes of hydrological regime and water quality after the construction of the reservoir were studied by comparative analysis. The results show that the project has some impact on the hydrological regime in the reservoir as the water level and the water depth would increase while the flow velocity would decrease after the construction of the reservoir. The water quality would be improved in different degree after the construction of the reservoir. For the sections which were near the dam, the degree of the water quality would be obviously improved.

Abstract: Yellow River Delta had been extensively engineered to control flooding and to protect coastal development which leaded to wetlands destruction and severe water pollution. The Yellow River Conservancy Commission decided the water supplement to the wetland during the water and sediment regulation period in 2010. In order to study the water quantity and distribution simulation, one-dimensional SOBEK model was used to flood simulation in the Yellow River Delta. The Re of the daily water level at four stations for the calibration period were 0.6%, 2.3%, 2.9%, 7.0%,.which indicated that the simulated values matched very well with the observed values. The SOBEK model had predicted the water level volume in 2003 within the range of acceptable accuracy. It indicated that the one-dimensional method SOBEK model was suitable for the flood simulation.

Abstract: The Wu River Basin in western China is experiencing extensive hydropower development. Concerns have been raised about the consequences of the development for the ecological environment. In this paper, we assess the cumulative effect of six hydropower stations on water quantity process in the upper Wu River by using a combination of measured data and a distributed hydrological model based on MIKE11. The results show that the operation of hydropower stations averaged the runoff distribution that increased the November-April discharge by 10-176% and decreased the May-October discharge by 6-38%. Furthermore, the effect of averaging runoff distribution would be more obvious along with the adjustment of hydropower cascade stations due to cumulative effect, the differential ratio of mean discharge in flood season and dry season decreased from 79.3% to 20.4% along with the hydropower stations. Thus the water quantity process in the upper Wu River has been significantly altered by cascade hydropower development, but what the consequences are for the ecological environment, needs further study.

Abstract: In order to explore the relationship between water consumption (WC) and economic growth (EG) in China, this paper introduced the concepts related with decoupling in the fields of resources and environmental research to define the decoupling EG from WC. Furthermore, the assessing approach was built up and a coefficient was proposed to estimate the decoupling degree. Afterwards, the relations between WC and EG from 1997 to 2008 were investigated. The results show strong decoupling of agricultural WC from GDP of primary industry and weak decoupling of WC from EG. It can be concluded that agricultural WC plays an important role to improve the decoupling degree between WC and EG.

Abstract: Regional groundwater exploitation is the foundation and basis for the groundwater resources administrative department to plan the rational utilization and protection of local groundwater resources. The dynamics characteristics and regularity of the local groundwater exploitation are studied in Tianjin from 1998 to 2009 by the methods of time-series analysis. The results show that it provides scientific basis for better understanding the present situation of groundwater exploitation objectively and planning the exploitation and utilization of groundwater resources reasonably.

Abstract: Settling velocity of sediment increases if flocculating occurred, and this enlarges deposition in reservoirs. According to water environmental factors in the Three Gorges reservoir, potential energy and forces between particles are evaluated based on DLVO theory. The critical water dynamics conditions were obtained by comparing extremum in synthetic potential curve and kinetic energy caused by relative velocity between particles. It is found that sediment flocculating is apt to happen when water level is high according to flow dynamics in the Three Gorges reservoir. The flocs are relatively loose and which is prone to be broken by water shear force. So the settling velocity of the flocculation is limited and the critical diameter of sediment is 0.019mm under which the sediments are affected by flocculating, and the settling velocity should be revised according to the limited settling velocity of flocculation when sediments are smaller than the critical diameter.

Abstract: The hydrodynamics in the Lingdingyang Bay of the Pearl River Estuary is complicated due to the combined effect of river runoff, tide and bathymetry. In this paper, the residual current patterns were investigated in the Lingdingyang Bay during the dry season based on Finite-Volume Coastal Ocean Model (FVCOM). The horizontal distributions of the residual current suggest that during both neap and spring tide the residual current is relatively strong at the surface while it weakens quite a lot at the bottom. Due to the northeasterly wind, a lateral circulation westward at the surface and eastward at the bottom is also found, which is more evident during neap tide than spring tide. The vertical profiles of residual current along deep channels show an obvious spring-neap variation, with the strongest estuarine circulation pattern during the moderate tide after neap.

Abstract: Fractures dominate the path for fluid flow in fractured rock masses, which is a main concern in groundwater protection, coal mine safety and energy exploitation, e.g., petroleum and geothermal resources. Intersection analysis is one crucial procedure for discrete fracture network modeling as it can provide necessary information for evaluating the connectivity of fractures. This paper is proposed to improve the performance of intersection analysis by means of parallel computing. The algorithm is designed in view of both the computational efficiency and the smooth connection with other procedures in modeling. Numerical study indicates that the proposed parallel algorithm is practical and can significantly reduce the calculation time of intersection analysis under large scale simulations.

Abstract: Poyang Lake is located in the northern part of Jiangxi Province, is one of the important Yangtze River flood storage lakes. Use Mann-Kendall test the trends and mutation of the Poyang Lake area rainfall time series, and use singular spectrum analysis (SSA) method to analyze the time series of periodic oscillation characteristics. The results showed that, the Poyang Lake area rainfall time series no significant upward or downward trend, there are quasi 4-5 years, 8-11 years, 20-year periodicity.

Abstract: The paper selects water price as a potentially effective socio-economic factor for the mitigation of conflict between socio-economic development and regional water resources in the Weihe River basin on basis of the driving mechanism research of socio-economic factors for water cycle, and evaluates the variation of socio-economic and hydrological variables by comprehensive simulation of economic system and water resources system by coupling of economic model CGE, water allocation model ROWAS and distributed water cycle model WEP. The results indicate that raising water price would bring down socio-economic development and regional water demand to some extent, but regional water resources tensions just reduce so slightly that corresponding schemes turn out to be not sufficient to deal with water crisis in the Weihe River basin.