五河控制性水库对鄱阳湖枯水期水文情势的影响

Influence of controlled reservoirs operation in five tributaries of Poyang Lake on hydrological regime in dry season

近年来,鄱阳湖区枯水期水位降低、枯水出现时间提前、枯水持续时间延长,对湖区经济社会发展、生态系统及生物多样性带来了严重影响。为明晰鄱阳湖水系水库蓄放水调度运用对湖区枯水期水文情势的影响,选择鄱阳湖水系赣江、抚河、信江、饶河、修水等五河上7座调节性能较好的控制性水库,运用长系列径流调节计算方法,定量分析了各水库现状调度方式对下游河道及鄱阳湖区的流量、水位影响。结果表明:9月至次年2月为鄱阳湖五河控制性水库供水期,各水库对鄱阳湖区均处于补水状态,现状调度方式下月均增加入湖流量62~289 m^(3)/s。修水柘林水库枯水期补水对下游虬津站水位抬升作用较大,鄱阳湖赣江、抚河和昌江上水库对下游控制站水位抬升作用较小。鄱阳湖五河控制性水库不同程度抬高湖区水位0.04~0.48 m,对鄱阳湖区目前出现的枯水期水位降低、枯水时间提前等现象无不利影响。

In recent years,the Poyang Lake suffered more decreased water lever and earlier and longer dry period in dry season,which has seriously affected the economic and social development,ecosystem and biodiversity of the lake area.In order to clarify the influence of reservoirs storage and operation on hydrological regime in the Poyang Lake Basin,we studied seven controlled reservoirs with better operation performance in its five tributaries(Ganjiang River,Fuhe River,Xinjiang River,Raohe River,Xiushui River).Impacts of reservoirs operation on the flow and water level of the downstream channel and the Poyang Lake area were quantitatively analyzed by long series runoff regulation calculation method.The results showed that September to February was water supply period of those reservoirs,during this period the seven controlled reservoirs supplied water to the Poyang Lake.Under the current scheduling mode,the monthly flow into the lake increased by 62~289 m^(3)/s due to reservoir regulation.The Zhelin Reservoir on the Xiushui River had a great effect on uplifting water level at the downstream Qiujin Station during dry season,while reservoirs on the Ganjiang River,Fuhe River and the Changjiang River had little effect.The controlled reservoirs in five tributaries raised the water level of the lake by 0.04~0.48m,which had no relation with the current lower water level and drying time advancing in the Poyang Lake area during the dry period.