气候变暖背景下青海汛期暴雨洪涝及次生灾害风险评估

本文根据自然灾害系统理论和暴雨洪涝灾害风险评估原理,基于基础地理信息数据和历史灾情数据,旨在利用青海50个气象站1961—2017年汛期(6—10月)的逐日气温、降水数据,通过对暴雨洪涝致灾因子危险性及孕灾环境易损性的研究,对气候变暖背景下青海省汛期暴雨洪涝及次生灾害的风险进行评估,得出：(1)1961年以来,青海省汛期平均气温升高、降水增加,降水日数及强降水日数增多,极端天气气候事件频发；(2)由短时强降水及连续性降水造成的洪水、渍涝灾害及其引发的滑坡、泥石流等次生灾害呈增多趋势,且7、8月份为青海省暴雨洪涝及其引发的次生灾害的高发期,占汛期灾害发生次数的77.9%；(3)贵德县、兴海县、贵南县、共和县、同德县、化隆县为青海省汛期暴雨洪涝及次生灾害发生次数最多、风险最为严重的县。本研究通过开展暴雨洪涝及其引发次生灾害风险评估工作,对暴雨洪涝的早期预警以及防灾减灾措施的及时制定和实施具有重要意义,可为气象防灾减灾建设工作提供决策信息。

Risk Assessment of Rainstorm Flood and Its Secondary Disasters During Flood Season in Qinghai Under Climate Warming

According to the natural disaster system theory and disaster risk assessment principles, this paper aims to assess the risk of rainstorm flood and its secondary disasters during flood season in Qinghai Province under the background of global warming by identifying the risk factors of rainstorm flood disaster and vulnerability of disaster environment, based on the daily precipitation and temperature data derived from the 50 meteorological stations in Qinghai from May to October during 1961-2017 and basic geographic information and historical disaster data. The results showed that: (1) the temperature, precipitation, (heavy) rainfall days, and extreme climate events had increased since 1961 in Qinghai province; (2) Floods and the secondary disasters such as landslides and debris flows caused by continuous or short-term heavy rainfall increased, and the peak of rainstorm flood and secondary disasters came up from July to August in Qinghai province which accounted for 77.9% of the total disasters in flood season; (3) the rainstorm flood and secondary disasters occurred most frequently and serious in Guide, Xinghai, Guinan, Gonghe, Tongde and Hualong. This study is of great significance to the early warning of rainstorm flood and the timely formulation and implementation of the measures for disasters prevention and reduction, providing decision-making information for the work of meteorological disaster prevention and reduction.