基于不同重现期的1960—2019年长三角地区区域降水风险评估

Risk assessment of regional precipitation in Yangtze River Delta from 1960 to 2019 based on different return periods

本文基于长三角地区1960—2019年逐日降水观测数据以及2015年1 km格网的GDP和人口数据,借助区域降水事件提取方法共识别出2109次区域降水事件,并利用不同分布函数确定不同重现期下降水强度和降水日数的阈值,进一步采用国际减灾战略(ISDR)的灾害风险评估模型,从危险性与脆弱性综合评价长三角地区区域降水风险及其空间分布特征。结果表明:(1)对于降水强度,GEV函数拟合效果最优;对于降水日数,EXP函数和POISS函数拟合效果最好;(2)长三角不同重现期下区域降水的危险性均从中部地区向南北两侧递减;(3)长三角脆弱性由东部沿海向内陆逐渐降低;(4)不同重现期下长三角区域降水风险均是由东部沿海向内陆降低,其中各大中心城市始终是高风险区。

Based on the daily precipitation data in the Yangtze River Delta from 1960 to 2019 and the GDP and population data of the 1 km grid in 2015,the regional precipitation event extraction method was used to identify a total of 2109 regional precipitation events and the different distribution function was used to calculate the threshold of the precipitation intensity as well as precipitation days under different return periods,moreover,the International Strategy for Disaster Reduction(ISDR)disaster risk assessment model was adopted to evaluate the risk of regional precipitation and its spatial distribution characteristics comprehensively in the Yangtze River Delta based on local risk and vulnerability.Results show that:(1)the GEV function has the best fitting effect for precipitation intensity;for the number of precipitation days,EXP function and POISS function have the best fitting effect.(2)The hazards of regional precipitation in the Yangtze River Delta at different recurrence periods decrease from the central region to the north and south sides.(3)The vulnerability of the Yangtze River Delta gradually decreases from the eastern coastal to the inland areas.(4)Under different return periods,the risk of precipitation in the Yangtze River Delta all reduce from the eastern coastal to the inland,among which the major central cities are always high risk areas.