广州市复合洪水及衍生滑坡灾害风险评估及 空间迁移规律研究

Risk Assessment and Spatial Migration Patterns of Compound Flood and Derived Landslide Disasters in Guangzhou,China

河口地区受高强度局部暴雨和潮位顶托作用的影响,复合洪水及衍生滑坡灾害频发。提出了一种复合洪水及衍生滑坡灾害风险评估及空间迁移规律研究的综合方法,以广州市为研究区,构建了广州市复合洪水及衍生滑坡灾害风险评估指标体系,采用加权综合评价法对多源复合灾害进行风险评估,并基于标准差椭圆法探究上述3种灾害的风险空间分布格局及灾害风险迁移规律。结果表明:①广州市有52.81%的地区属于中高风险及高风险区域,复合洪水及衍生滑坡灾害风险整体上呈现东北高西南低的特点,其中从化区和增城区风险较高,因此,应对以上区域采取防灾减灾措施降低灾害风险;②暴雨洪水-复合洪水-复合洪水及衍生滑坡灾害的风险重心先向西南方向移动后向东北,灾害风险呈现西南—东北分布格局,灾害风险的聚集效应先增强后逐渐减弱。研究结果可为复合灾害的风险决策及防灾规划提供科学依据。

Compound floods and derived landslide disasters are frequent in estuaries under the influence of high-intensity localized heavy rainfalls and tidal level top support.This paper proposes a comprehensive method for risk assessment and spatial migration patterns of compound flood and derived landslide disasters.Meanwhile,taking Guangzhou as the study area,it constructs the index system for risk assessment of compound floods and derived landslide disasters in the city.Additionally,the weighted comprehensive evaluation method is adopted to assess the risk of multi-source compound disasters,and the spatial risk distribution pattern of the above-mentioned three types of disasters and the migration law of the disaster risk are explored based on the standard deviation ellipse method.The results are as follows:①52.81%areas of Guangzhou are medium-high risk and high-risk ones,and the risk of composite floods and derived landslide disasters as a whole presents the characteristics of high risk in the northeast and low risk in the southwest,among which the risk of Conghua District and Zengcheng District is higher.Thus,disaster prevention and mitigation measures should be taken to reduce the disaster risks in the above areas.②The center of gravity of the risk of heavy rainfall flooding-composite flooding-composite flooding and derived landslide hazards first moves to the southwest and then to the northeast,and the disaster risk shows a southwest-northeast distribution pattern,with the first enhanced and then gradually weakened aggregation effect of disaster risks.The results can provide a scientific basis for the risk decision-making of compound disasters and disaster prevention planning.