中国短历时和长历时暴雨对总暴雨贡献的空间差异性研究(1961-2015)

Spatial pattern difference between contribution of short and long duration heavy rainfall to total heavy rainfall in China from 1961 to 2015

采用1961-2015年659站日值降水数据,以持续1 d和持续2 d及以上暴雨作为短和长历时暴雨标准,分析不同历时暴雨变化趋势,结果表明,中国总降雨、总暴雨和短历时暴雨从东南沿海向西北内陆依次呈"增-减-增"的分布特征,且整体以增加趋势的站点占主导,而长历时暴雨则呈现出"增-减"的分布特征,且整体以减少趋势的站点占主导,并且检测出中国自东北向西南存在一条变干带。同时中国总暴雨对总降雨、长历时暴雨对总暴雨的贡献呈现出"东南高-西北低"的分布特征,而短历时暴雨对总暴雨的贡献呈现出"东南低-西北高"的分布特征。中国总暴雨对总降雨、短历时暴雨对总暴雨贡献的变化趋势呈现出"增-增减镶嵌-增"的分布特征,且以增加趋势的站点占主导,而长历时暴雨在东部沿海地区呈现出增减镶嵌的趋势,而西北内陆地区呈略微减少趋势,且以减少趋势的站点占主导,也检测出自东北向西南存在一条气候过渡带并与上述变干带基本重合。

Many regions are pounded with heavy rainfall,causing flood,casualties,property damage and severe destruction to ecosystem in multiple urban areas. Frequent occurrence of extremely heavy precipitation event under the background of global climate change has caused terrible harm on economic and social development,life security,ecosystem,etc.,brought profound impact on sustainable development of disaster area,become a key factor of global and regional disasters and environmental risk,and been widely concerned by academic circle and all sectors of the society. So severe disasters caused by extreme precipitation events have attracted more and more attention,and the relationship between different duration heavy rainfall and total heavy rainfall becomes the hottest scientific frontier issue. Different duration heavy rainfall＇s contribution to the total heavy rainfall has significant spatial differences. Here we use daily rainfall data from 1961 to 2015 of 659 meteorological stations in China.When the rainfall is greater than 50 mm in 24 hours,it is a heavy rainfall event. Heavy rainfall that only lasts for one day is defined as short duration heavy rainfall,while that lasts for more than two days is defined as long duration heavy rainfall. Results indicate that： total rainfall,total heavy rainfall and short duration heavy rainfall showed＂increasing-decreasing-increasing＂from the southeast coastal to northwest inland in China from 1961 to2015,and the meteorological stations with increasing trend were predominant. In the meantime,long duration heavy rainfall showed＂increasing-decreasing＂spatial pattern,and meteorological stations with decreasing trend were predominant. There was a belt of becoming drought from northeast to southwest. The contribution of total heavy rainfall to total rainfall and long duration heavy rainfall to total heavy rainfall showed＂high in southeast-low in northwest＂spatial distribution pattern. On the contrary,the contribution of short duration heavy rainfall to total heavy rainfall showed＂low in southeast-high in northwest＂spatial distribution pattern. The contribution trend of total heavy rainfall to total rainfall and long duration heavy rainfall to total heavy rainfall showed＂increasing-mosaic with increasing and decreasing-increasing＂spatial distribution pattern from northeast to southwest,and on the whole meteorological stations with increasing trend were predominant. On the contrary,the contribution trend of short duration heavy rainfall to total heavy rainfall showed mosaic with increasing and increasing in the northeast,slightly decreasing in the southwest,and meteorological stations with decreasing trend were predominant. There was a climate transition zone from northeast to southwest,which were essentially coincident with the arid zone. The results suggest that the precipitation in China is changing to extremely accompanied by the significant short duration storm increasing. Chinese heavy rainfall,especially the increase of short duration heavy rainfall suggests that human activity is likely to be triggered an increasing in extreme precipitation.