摘要
随着全球气候变暖,极端降雨事件呈现明显增加趋势,引发严重的水土流失等生态问题。现有研究大多基于日、月或年的极端降雨特征数据分析,对小时尺度极端降雨时空演变特征的研究相对较少。研究极端降雨特征的小时尺度,可为认知和预防极端降雨事件造成的土壤侵蚀及次生灾害提供基础。基于全球0.5 h卫星降水观测数据,采用Mann-Kendall分析方法和线性倾向率法,以西南喀斯特高原石漠化地区为研究区,分析1 h降雨量极值的年际、年内时空演变规律。结果表明:1)2000—2020年,研究区1 h降雨量极值呈小幅度上升趋势,倾向率为0.5353 mm/a;1 h降雨量极值随年份变化出现3个明显峰值期,峰值不断增大而间隔时间缩小。2)Mann-Kendall检验表明,研究区从2019年起,1 h降雨量极值呈现显著上升趋势,极值范围在65~223 mm,存在明显空间异质性;发生频率为95%的1 h降雨量极值空间分布为西北高、东南低,而低于该频率的1 h降雨量极值呈现东南高、西北低的空间分布特征。3)此外,在春季与夏季,1 h降雨量极值呈现东南高、西北低的空间分布特征;从夏末8月开始,1 h降雨量极值空间分布呈相反特征。该结果可为提升极端降雨下土壤侵蚀及次生灾害风险评估和制定防治策略等提供指导依据。
[Background]With the increasing severity of global climate change,extreme rainfallevents in China have also shown a significant trend of increasing.In the karst plateau of southwestern China,most of the existing studies are based on daily,monthly or annual data analysis of the region’s extreme rainfall characteristics.Research on the spatial and temporal evolution characteristics of extreme rainfall at the hourly scale are relatively rare.Conducting research on the hourly scale extreme rainfall characteristics in the karst plateau area can provide a basis for understanding and preventing soil erosion.[Methods]Based on the 0.5 h satellite rainfall data of global precipitation observation,the extreme rainfall series through the threshold values of different percentile rainfall were extracted,and Mann-Kendall analysis method,climate factor tendency rate method and other analysis methods were used to calculate the relationship between various indicators,and analyze the inter-annual and intra-year spatio-temporal evolution of 1 h rainfall extreme value in the rocky desertification area in Southwest China karst plateau.[Results]1)From 2000 to 2020,the 1 h rainfall in the study area showed a small upward trend,with a tendency rate of 0.5353 mm/a.There were 3 distinct peak periods of 1 h rainfall with the change of year,and the peak value increased continuously while the interval time decreased.2)Mann-Kendall test showed that the 1 h rainfall extreme value in the study area showed a significant upward trend from 2019.In addition,the maximum rainfall of 1 h in the study area ranged from 65 to 223 mm,and there was obvious spatial heterogeneity.The spatial distribution characteristics are influenced by the frequency and monthly variation of rainfall intensity.While the spatial distribution of 1 h rainfall extremes with a frequency of 95%was high in the northwest and low in the southeast,the spatial distribution characteristics of 1 h rainfall extremes below this frequency were high in the southeast and low in the northwest.3)In addition,in spring and summer,1 h rainfall extremum presented a spatial distribution feature of high southeast and low northwest,and the spatial distribution of 1 h rainfall extremum presented an opposite feature from the end of summer and August.The results showed that the study area will face more intense extreme rainfall hazards.At the same time,when considering the formulation of corresponding prevention and control strategies,the prevention and control standards of the areas with relatively large rainfall in 1 h should be improved.[Conclusions]Based on highresolution sub-hourly satellite data,this study explores the spatio-temporal evolution of hourly rainfall extremes in the rocky desertification area of southwest China from 2000 to 2020.The results are helpful for predicting soil erosion potential caused by rainfall under future climate change conditions.It can provide guidance for improving the risk assessment of soil erosion and secondary disasters under extreme rainfall and formulating prevention and control strategies.
作者
黄晨洋
王鑫
严友进
王良杰
戴全厚
HUANG Chenyang;WANG Xin;YAN Youjin;WANG Liangjie;DAI Quanhou(Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,210037,Nanjing,China;Jiangsu Provincial Key Laboratory of Soil and Water Conservation and Ecological Restoration,Nanjing Forestry University,210037,Nanjing,China;College of Forestry,Guizhou University,550025,Guiyang,China;Institute of Soil Erosion and Ecological Restoration,Guizhou University,550025,Guiyang,China)
出处
《中国水土保持科学》
北大核心
2025年第4期55-64,共10页
Science of Soil and Water Conservation
基金
国家重点研发计划“低质低效人工林群落结构与生态系统服务对气候变化的响应”(2023YFF130440102)
中国博士后科学基金“极端暴雨对喀斯特石漠化坡地土壤侵蚀的影响机制研究”(2020M673296)。
作者简介
第一作者:黄晨洋(2001-),女,硕士研究生。主要研究方向:林业生态工程。E-mail:732316678@qq.com;通信作者:严友进(1990-),男,硕士生导师。主要研究方向:土壤侵蚀与生态修复。E-mail:yyj_erosion@163.com。
