广州市高温脆弱性空间分异格局及主导因素研究

Spatial pattern and influencing factors of heat vulnerability:The case of Guangzhou City

气候变化对人类健康的威胁正在日益加剧。立足地理学视角,开展特大城市高温脆弱性评估研究,对城市高温风险调控和防灾减灾策略的制定具有重要指引意义。论文以广州市中心城区为研究区域,从“暴露度—社会敏感性—物理敏感性—适应能力”4个维度构建高温脆弱性评估框架;采用等权重—函数模型法、熵值—函数模型法和主成分分析法分别计算高温脆弱性得分,并结合热相关死亡数据,运用十折交叉验证方法检验不同脆弱性评估结果的准确性;基于准确性最高的高温脆弱性评估结果,揭示广州市高温脆弱性的空间分异格局并识别其主导因素。结果表明:①广州市中心城区的高温脆弱性整体呈现以老城区、老黄埔区和白云区西片区、天河区南片区为四大高地,高温脆弱性高、较高区域沿着城市建成区扩展方向分布,其中老城区内环路环绕的城市中心区域为极高高温脆弱性社区的集聚区域;②老年人口占比、老年人自评为健康状态占比、独居老年人口占比、住房建成年代在1990年之前的占比和高温日地表温度均值为影响社区高温脆弱性的主导因素;③地表温度均值、老旧住房占比和老年人自评为健康状态占比主要作为第1~3位障碍因子,对于抑制社区高温脆弱性发挥重要作用,适应能力相关指标的障碍因子排名相对靠后。

Climate change increases the intensity,frequency,and duration of heatwave events that present a threat to human health.Fine-scale heat vulnerability assessment of megacities through a geographical perspective has important guiding significance for high-temperature disaster risk prevention and mitigation.This study aimed to explore the spatial differentiation pattern and influencing factors of heat vulnerability in the central urban area of Guangzhou City.First,we established a model of heat vulnerability based on four components including exposure,social sensitivity,physical sensitivity,and adaptive capacity,and adopted 14 indicators to assess population heat vulnerability at the community level.Second,we used equal weight approach(EWA),entropy weight method(EWM),and principal component analysis(PCA)to calculate heat vulnerability respectively,and validated three assessment results using heat-related mortality.Then based on the specific assessment of heat vulnerability that has the strongest correlation with heat-related mortality,we explored the spatial differentiation pattern of heat vulnerability in Guangzhou City.An obstacle degree model was furthered employed to explore the driving factors of heat vulnerability.Our findings indicate that heat vulnerability shows significant spatial agglomeration.The areas with high heat vulnerability are mainly distributed along the expansion direction of the urban built-up area.Communities within the inner ring road have extremely high heat vulnerability,characterized by high exposure,high social sensitivity,high physical sensitivity,and high adaptive capacity.Communities with high heat vulnerability should pay particular attention to the elderly population,especially the elderly with poor health and living alone.Meanwhile,decades-old residential communities and communities at risk of high heat exposure should also make multi-pronged heat action plans to reduce heat-related mortality and morbidity.This study enriches the assessment framework of heat vulnerability for risk identification,driving factor exploration,and developing strategies for the prevention and mitigation of heatwave disasters for urban communities.