Fault－weakening effect of reservoir temperature of hot spring and its influence on seismic activities

In this paper, the reservoir temperatures of 14 hot spring samples collected from the northern segment of theRed River Fault are calculated by using the mixing-model of SiO2-geothermometer. Based on the features ofreservoir temperatures and densities of hot springs, the northern segment of the Red River Fault is furtherdivided into 4 sub-segments. The influence of weakening effect of water on seismic activities is discussed fromthe view point of fault-weakening effect of water. It is suggested that the difference in seismic activity between various sub-segments is principally caused by the difference in intensity of the fault-weakening effect ofwater of these sub-segments. The Eryuan sub-segment where the reservoir temperatures are high and the hotsprings are dense corresponds to a slipped region, however, the Jianchuan and Midu sub-segments where thereservoir temperatures are lower and the hot springs are fewer as well as the Dan sub-segment where the hotspring are very few all correspond to locked regions. It is suggested that Dan sub-segment is the riskiest region for strong earthquake preparation, while the possibility for strong earthquake preparation is very little inthe Eryuan sub-segment.

Development of an integrated modeling system for improved multi-objective reservoir operation

Reservoir is an efficient way for flood control and improving all sectors related to water resources in the integrated water resources management.Moreover,multiobjective reservoir plays a significant role in the development of a country’s economy especially in developing countries.All multi-objective reservoirs have conflicts and disputes in flood control and water use,which makes the operator a great challenge in the decision of reservoir operation.For improved multi-objective reservoir operation,an integrated modeling system has been developed by incorporating a global optimization system(SCE-UA)into a distributed biosphere hydrological model(WEB-DHM)coupled with the reservoir routing module.The new integrated modeling system has been tested in the Da River subbasin of the Red River and showed the capability of reproducing observed reservoir inflows and optimizing the multi-objective reservoir operation.First,the WEB-DHM was calibrated for the inflows to the Hoa Binh Reservoir in the Da River.Second,the WEB-DHM coupled with the reservoir routing module was tested by simulating the reservoir water level,when using the observed dam outflows as the reservoir release.Third,the new integrated modeling system was evaluated by optimizing the operation rule of the Hoa Binh Reservoir from 1 June to 28 July 2006,which covered the annual largest flood peak.By using the optimal rule for the reservoir operation,the annual largest flood peak at downstream control point(Ben Ngoc station)was successfully reduced(by about 2.4 m for water level and 2500 m^(3)·s^(-1) for discharge);while after the simulation periods,the reservoir water level was increased by about 20 m that could supply future water use.