Precipitation Change Character In China And Its' Response To Climate Warming

Based on daily precipitation and temperature data from 287 meteorological stations(1960-2017),we analyzed the temporal and spatial change character of precipitation in China over the past half century,and studied the variations of dry and wet conditions in various regions of China.Based on temperature and saturation deficit,we analyzed the response of precipitation character to climate warming in China.At the same time,the influence of other factors on the change of precipitation character was discussed.We obtain the following conclusions:(1)During the past 58 years,the annual precipitation had not changed significantly at the national scale.The annual precipitation frequency had decreased significantly,and the precipitation intensity had increased significantly,change at rate-1.92%/10a and 3.10%/10a,respectively.In the northwest and east of China,the annual precipitation had increased significantly,at the rate of 5.50%/10a and 1.43%/10a,respectively.The annual precipitation frequency was significantly reduced in most region expect the northwest.The average intensity of precipitation events had increased in all regions.(2)There were spatial differences in the change character of different intensity precipitation events.The amount and frequency of micro-precipitations(0.1-0.9mm),light and moderate precipitation events had decreased significantly in the east,southeast,southwest and north plain of China,while there was no significant changes in the north central,northwest and Tibetan Plateau of China.Extreme precipitation events didn't increase nationwide,only in the east(amount of precipitation:4.10%/10a;frequency of precipitation:3.66%/10a)and the northwest China(amount of precipitation:10%/10a;amount of precipitation:8.47%/10a)extreme precipitation events showed significant increase trend.(3)The Gini coefficient of precipitation had decreased significantly across China,at a reduction rate of 0.114%/10a,and the largest reduction was in the southeast where the Gini coefficient was the highest.The decrease in the Gini coefficient of precipitation indicated the annual precipitation was less unevenly distributed on wet days.The partial correlation analysis showed that the micro-precipitation events and light precipitation events were the main reasons for the decrease of Gini coefficient in China.(4)With the increase of precipitation in the northwest,the frequency of dry spells increased,but the average length of dry spell shortened.At the same time,the total number of rain days in wet spells and the frequency of wet spells showed an increasing trend.In the east,southeast and southwest of China,although the annual precipitation had increased,the total number of dry days in dry spells,the frequency of dry spells,the frequency of prolong dry spells,the average length of prolong dry spells and the number of dry days in prolong dry spells all showed increasing trend.The average length of wet spell was shortened,but the average precipitation in the wet spells and the intensity of precipitation in the isolated wet days had significantly increased.As a result,the risk of flooding increased accompanied by the increased risk of short-term drought in the east,southeast and southwest of China.(5)With global warming,temperature also rose rapidly from the early 1980s to the end of the 1990s.Our research found that,after the rapid rise of temperature,the light and moderate precipitation events had decreased in the north plain,east,southeast and southwest of China,and increased in the Tibetan Plateau and northwest of China.In the east,northwest and southwest,the extreme precipitation events had increased.Correlation analysis showed that compared with the effect of warming on extreme precipitation events,the effect on light and moderate precipitation events were more pronounced.Besides the temperature,the summer monsoon,water vapor flux,aerosol concentrations in atmosphere and land use patterns might have impacts on changes in precipitation.