Precipitation has become more concentrated in Shanghai since the 1990s.For revealing the changing characteristics of precipitation resource in Shanghai since the 1990s and working out more scientifically measures of controlling flood and combating drought in Shanghai,the statistical characteristic changes of precipitation,the number of precipitation days,relative humidity,evaporation,and the number of snowfall days since the 1990s were studied based on analysis of precipitation data of 11 meteorological stations during the last 13 year(1991-2003) in Shanghai and compared with the mean values of the first 30 years(1961-1990).The results showed the annual average precipitation increased 11%,the average precipitation of flood season increased 18%,the annual average precipitation days decreased 2d,the annual average precipitation intensity increased 12%,the seasonal distribution pattern of precipitation changed,and the regional distribution pattern of precipitation remained unchanged;the annual average relative humidity and evaporation decreased slightly,the annual average snowfall days decreased 5d in Shanghai since the 1990s.The summer precipitation increased evidently and the autumn precipitation decreased.Such a variational difference resulted in changes in precipitation distribution pattern of the four seasons,and much more prominence in drought and waterlogging phenomena in Shanghai.However,the geographic distribution pattern of precipitation of various seasons did not change,only the regional difference became greater. Since waterlogging rather than drought has always been a headache in Shanghai,the flood control departments of the city should attach importance to dealing with serious disasters induced by concentrated summer precipitation.
HE Fangfang, XU Jialiang.
Studies on Precipitation Resource Change in Shanghai since the 1990's[J]. JOURNAL OF NATURAL RESOURCES, 2006, 21(2): 210-216 https://doi.org/10.11849/zrzyxb.2006.02.007