城市化进程对暴雨洪涝灾害风险影响效应研究——以闽三角地区为例

Effect of urbanization on the rainstorm and flood disaster risk:A case study of Min Delta

暴雨洪涝灾害是威胁城市持续稳健发展的常见灾种,城市化对灾害风险存在加剧或抑制的复杂作用。以闽三角为例,基于多源数据、GIS多准则评价、BP神经网络模型辨识风险分布,采用空间计量模型分析社会经济城市化、土地城市化与灾害风险的特征,判断不同城市化水平的高风险区分布及风险因子对灾害的影响效应。结果表明:(1)闽三角综合高风险区主要分布于河流沿岸、河口和湾区附近;(2)社会经济城市化水平较高的地区脆弱性高,城市化水平较低的地区危险性高;(3)洪涝灾害风险与土地扩展强度存在显著聚类和空间正相关的可能性,而快速城市化地区更容易受到洪涝灾害风险的威胁;(4)空间滞后模型计算结果表明危险性风险与人口聚集为正相关,与社会经济活动活力存在负相关,即人口密度大、社会经济失活,灾害危险性越高。最后针对不同城市化水平高风险点提出灾害防控建议。

Rainstorm and flood disaster is a common disaster threatening the sustainable and steady development of cities.The process of urbanization has a complex effect on aggravating or restraining disaster risk.Taking Min Delta as an example,the characteristics of socio-economic urbanization,land urbanization,and disaster risk were analyzed,the distribution of high-risk areas with different urbanization levels and the impact of risk factors on disaster risk were judged based on multi-source data,GIS multi-criteria risk assessment,BP neural network model and spatial econometric model.The results show that:(1) The comprehensive high-risk areas are mainly distributed along the river,near the estuaries and the bay area;(2) Regions with higher levels of socio-economic urbanization are vulnerable,and low level of urbanization with high-risk;(3) There are significant clustering and positive spatial correlation between flood disaster risk and land expansion intensity,while rapid urbanization area and highly urbanized area are more vulnerable to flood disaster risk;(4) The results of the spatial lag model show that the risk is positively correlated with population aggregation,and negatively correlated with the vitality of social and economic activities,that is,the higher the population density,the more passive the socio-economic activities,and the higher the risk of disasters.Finally,the suggestions were put forward for disaster prevention and control at high-risk points of different urbanization levels.