Abstract:

The effect on the regional climate caused by changes of underlying surface after the foundation of Three Gorges Reservoir was simulated by 〖JP2〗MM5V3,a mesoscale numerical model.Whether the foundation〖JP〗 of Three Gorges Reservoir will be a main factor of severe drought and heat wave,as well as low temperature,consecutive cryogenic freezing rain and snow disasters,which are issues concerned intensively by society,was discussed.The results show that the foundation of Three Gorges Reservoir will have a sealike effect to the local temperature.The temperature decreases in spring around the reservoir areas.And in summer,the temperature increases in downstream of reservoir while decreases in the upper stream of reservoir.In winter the temperature increases on the whole.Change of precipitation in spring mainly locates in south mountain area along the reservoir,and the increasing rainbands alternate with the decreasing rainbands.In summer,precipitation increases along the middle and upper reaches of Three Gorges Reservoir and the nearby mountain areas,but precipitation decreases in areas around downstream reservoir.And in winter,precipitation decreases mainly from dam areas to Wushan in Three Gorges.It is also found that the relative humidity of reservoir areas increases in spring, with a range of about 05~10%.In summer,〖JP2〗relative humidity increases〖JP〗 in areas around upper stream of the reservoir,but decrease in areas around downstream reservoir.Relative humidity changes little in winter.In conclusion, Three Gorges Reservoir water conservancy project is not the main inducement of extreme weather disasters such as drought, low temperature and consecutive cryogenic freezing rain.〖