关键词: 气候要素, MannKendall, 时空特征, 变化趋势, 太湖流域

Abstract:

In recent years,the occurrence of extreme events such as floods is rising throughout the worldwide.The better understanding on the relationships among climate change,human activities and the flood occurrence will allow water authorities to make more rational decisions on flood control and management.The annual and seasonal precipitation,temperature,relative humidity and sunshine duration in the Taihu Basin from 1954 to 2006 were analyzed to obtain the spatialtemporal characteristics of longterm trend by using the MannKendall trend test and departure curve method.The results showed that the air temperature and precipitation all exhibited an increasing tendency,and the MannKendall slopes are 0.27℃/10 a and 1.97 mm/10 a，respectively;the relative humidity and sunshine duration showed a decreasing tendency,and the MannKendall slopes are -0.99%/10 a and -7.8 h/a，respectively during the past 53 years.In addition,the results indicate that there is a large seasonal difference of variation for trend in the Taihu Basin, and there is remarkable warming trend in winter,and great increasing of precipitation in summer and winter.In spring and autumn,the intensity and extent of relative humidity variation is larger than that in other seasons.The sunshine duration in four seasons decreased but the magnitude of trend in spring is weak.The magnitude of precipitation increases from northern to southeastern parts,the longterm trend decreases in northern parts and increases in southeastern area.The air temperature remarkably increased over the basin,but strongly in northeastern and southern parts.The longterm trend of sunshine greatly decreased in the study area and the amplitude of the sunshine decreases from western to eastern parts.The results will be helpful to further investigate the impact of the climate change on water resources and flood prevention in the Taihu Basin.It will also provide scientific references for the development of future climate change scenarios in the Taihu Basin.

Key words: climatic elements, MannKendall, spatialtemporal characteristics, trend, Taihu Basin