供需视角下雨洪调节关键区识别及规划策略研究

Identification and planning strategy of rainfall and flood regulation key areas from supply and demand view

雨洪调节服务供需测度对识别易涝区域、合理配置自然资源、优化雨洪安全格局具有重要意义。目前的研究多从供给或需求单一角度聚焦中心城区雨洪调节能力,而全域尺度雨洪调节服务供需测度实证研究较少,雨洪调节服务供需空间分布特征和影响供需平衡的关键驱动因子有待探究。以湖北省通城县为例,通过SCS-CN模型量化县域生态空间雨洪调节服务供给能力,利用洪水脆弱性指数评估社会经济对雨洪调节服务的需求水平,进而识别县域雨洪调节服务供需空间分布特征及失衡关键区域;结合斯皮尔曼相关系数分析和冗余分析,探究影响供需失衡的关键因子,并考虑人口密度和建设用地面积对雨洪调节服务供需的影响,从“宏观-中观-微观”3个尺度构建雨洪安全格局。研究结果表明:①县域内雨洪调节服务供需空间存在显著的分异情况,因此需要从整体角度构建和优化雨洪安全格局;②中心建成区是雨洪调节服务供需失衡最严重的区域,需要采取雨洪安全管控和修复措施;③县域内雨洪调节服务供需失衡的关键影响因子是人口密度,与雨洪灾害风险等级呈负相关。研究成果可为识别雨洪调节服务供需失衡区域以及优化国土空间规划体系下多尺度雨洪安全格局提供量化支持和依据。

The assessment of supply and demand of rainfall and flood regulation service is of great significance for identifying water-logging areas,allocating natural resources rationally,optimizing rainfall and flood security patterns.Current researches mostly focus on the capacity of urban rainfall and flood regulation from the single view of supply or demand,but overlook the empirical research on the measurement of the supply and demand of the whole-scale rainfall and flood regulation service.And characteristics of spatial distribution and key driving factors affecting the balance of supply and demand for rainfall and flood regulation services remain to be explored.Taking Tongcheng County,Hubei Province as a case,this research quantified the supply capacity of spatial rainfall-flood regulation services at the county level through SCS-CN Model.Additionally,we evaluated the level of social and economic demand for rainfall and flood services using flood vulnerability indexes,identifying the spatial distribution characteristics of supply and demand and the key areas of the imbalance at the county level.Combining spearman correlation coefficient analysis and redundancy analysis,we investigated the key factors affecting the supply and demand imbalance,considering the effects of population density and construction land area on the supply and demand of rainfall and flood regulation service.Finally,rainfall and flood security patterns were built at the three scales:macroscopic,intermediate perspective,microscopic.The results proved that:①significant spatial difference exists in rainfall and flood regulation supply and demand in the county,necessitating an overall perspective in constructing and optimizing rainfall and flood safety patterns.②the central built-up area is the area with the most serious imbalance between supply and demand of rainfall and flood regulation,requiring rainfall and flood safety management and restoration measures.③the key factor influencing rainfall and flood regulation imbalance in the county is population density,which has a negative correlation with the risk level of rainfall and flood disasters.This research provided quantitative support and basis for identifying areas of imbalance in rainfall and flood regulation supply and demand,as well as optimizing the multi-scale rainfall-flood safety patterns within the territorial spatial planning system.