福建省暴雨时空演变规律与洪涝灾害脆弱性曲线研究

Study on the temporal and spatial evolution law of extreme rainstorm andthe vulnerability curve of flood disaster in Fujian Province

【目的】日益频繁的极端天气导致全球各地面临严重的洪涝灾害,我国东南沿海地区长期受洪涝灾害困扰,且灾害风险日益增大。鉴于此,系统分析福建省洪涝灾害的致灾因子——暴雨的时空特征,构建暴雨-洪涝灾情脆弱性曲线,以期为福建省洪涝灾害的灾情评估提供科学支撑和方法借鉴。【方法】基于1960—2020年福建省22个国家气象站逐日降水数据和1950—2020年福建省洪涝灾害灾情数据,利用趋势拟合、Mann-Kendall趋势分析和突变检验方法,分析了福建省极端降水进行时空分异特征,采用多元回归线性模型拟合极端降水与农业、人口和经济等灾情指标,构建洪涝灾害的脆弱性曲线。【结果】结果表明:福建省极端降水时空分布不均且极端降水的发生频率呈增多趋势,农业、人口和经济等灾情指标趋势不同,拟合的最优脆弱性曲线模型为:受灾面积与播种面积的比率(农业受灾面积损失率)=0.001×年总降水量+0.002×年特大暴雨降水量-0.107。【结论】福建省洪涝灾害的农业受灾面积、成灾面积及直接经济损失等灾情指标总体上呈上升趋势,受灾人口和死亡人口呈下降趋势。灾情指标的趋势变化与日益增强的防灾减灾能力密切相关。脆弱性曲线可为未来洪涝灾害灾情评估与防灾规划的制定提供科学参考。

Increasing frequent extreme weather has led to serious floods around the world.The southeast coastal regions of China have been affected by floods for a long time with an increasing risk.In view of this,the spatial and temporal characteristics of rainstorm,the disaster-causing factor of flood disaster in Fujian Province were systematically analyzed.The vulnerability curve of rainstorm-flood disaster was constructed to provide a scientific support and reference for the disaster assessment of flood disaster in Fujian Province.Based on the daily precipitation data of 22 national meteorological stations from 1960 to 2020 and the flood disaster data of Fujian Province from 1950 to 2020,the spatial and temporal differentiation characteristics of extreme precipitation in Fujian Province were analyzed by using trend fitting,Mann-Kendall trend analysis and mutation test.The multiple regression linear model was used to fit the extreme precipitation and disaster indicators such as agriculture,population and economy for constructing the vulnerability curve of flood disaster.The results indicate that the spatial-temporal distribution of extreme precipitation in Fujian Province is uneven and the frequency of extreme precipitation is increasing.The trends of flood disaster losses in agriculture,population,and economy are different.The optimal multiple linear regression model is:the ratio of disaster area to cultivation area(agricultural disaster area loss rate)=0.001×total annual precipitation+0.002×annual extremely heavy rainstorm precipitation-0.107.The agricultural affected area,disaster area and direct economic loss of flood disaster in Fujian Province are generally increasing,while affected population and death of population are decreasing.This trends are closely related to the increasing ability of disaster prevention and mitigation.The vulnerability curve could provide a scientific reference for future flood disaster assessment and disaster prevention planning.