云贵高原典型区域气象灾害时空演变特征及影响因素分析

Spatiotemporal evolution characteristics and influencing factors analysis of meteorological disasters in typical regions of the Yunnan-Guizhou Plateau

目前气象灾害研究主要以时空分布规律和典型气象灾害风险评估为主,在对气象灾害进行系统的时空演变及影响因素研究方面还相对薄弱。为了揭示云贵高原典型气象灾害时空演变特征及影响因素,本研究基于大理州1984~2021年的历史气象灾害灾情统计数据,利用Arc GIS的标准差椭圆法、新兴时空热点分析和地理探测器,分析了大理州气象灾害时空演变特征及影响因素。结果表明:(1)时间上,大理州气象灾害集中发生在5~9月,历史气象灾害时间在年际变化上可分为三个阶段;(2)空间上,气象灾害发生密度较高的县(市)主要分布在大理市和鹤庆县;(3)时空变化上,5~7月气象灾害中心集中分布在大理市,移动方向为先北再西南后向北移动,鹤庆县出现新增热点;(4)地理探测器结果显示,24 h累计降水量、坡度和河网密度是引起暴雨洪涝灾害的主要原因。研究成果有助于认识大理州气象灾害的时空演变趋势和主要影响因素,从而为气象灾害防治工作提供技术支撑与理论指导。

China is one of the countries most affacted by natural disasters globally,and the study of meteorological disasters holds significant importance.Scholars have carried out various studies on meteorological disasters,mainly focusing on spatial and temporal distribution patterns,risk assessment of typical meteorological disasters,with relatively weak emphasis on the systematic spatial and temporal evolution of meteorological disasters and the study of influencing factors.The purpose of this paper is to summarize the spatial and temporal distribution law of meteorological disasters in Dali,analyze their spatial and temporal migration changes,and explore the main influencing factors behind flooding disasters in Dali as an example.In this study,we analyzed the temporal and spatial evolution characteristics of meteorological disasters in Dali,a typical region on the Yunnan-Guizhou Plateau,using historical meteorological disaster statistics from 1984 to 2021.We employed methods such as the standard deviation ellipse method,emerging spatiotemporal hotspot analysis,and geodetector of ArcGIS.The standard deviation ellipse method depicted spatial distribution and migration changes of meteorological disasters in different periods.Cold hotspot analysis visualized statistically significant clusters and the trend of meteorological disaster points over time.Geodetector identified spatial differences in weather hazards and revealed the driving forces behind them.The results showed that:①Temporally,meteorological disasters in Dali are concentrated from May to September,and the time of historical meteorological disasters can be divided into three stages in terms of inter-annual changes:the number of meteorological disasters in the first stage is relatively small,all of them are in the range of 20 and below.The number of meteorological disasters in the second stage has increased,with an average number of disasters per year of 29.The number of meteorological disasters in the third stage shows a significant increase in the trend.②Spatially,weather disasters occurred with higher density in Dali City and Heqing County.In terms of the degree of hazard,three townships had a very high degree,and five townships had a high degree of hazard.③Temporally and spatially,from May to July,meteorological disaster centers concentrated in Dali City,moving from north to southwest and then to north,with new hot spots in Heqing County.④Geographical detectors identified 24-hour accumulated rainfall,slope,and river network density as the main causes of rainstorm and flood disasters.The results help to understand the spatiotemporal evolution trend and main influencing factors of meteorological disasters in Dali,thereby providing technical support and theoretical guidance for meteorological disaster prevention and control work.