基于综合灾害风险评估的高原山区乡村聚落空间优化--以青海省海东市乐都区为例

Spatial Optimization of Rural Settlements in Plateau Mountain Area based on Comprehensive Disaster Risk Assessment:A Case Study in Ledu District,Haidong City in Qinghai Province

自然灾害评价是衡量资源环境承载能力和国土空间开发适宜性的本底要素。以青海省海东市乐都区为研究区,采取频数统计和优化AHP法确定研究区灾种和孕灾因子体系双层权重,利用GIS技术分析评价灾害易发风险区划和几何拓扑特征。结果表明:①乐都区综合灾害极高和高风险易发区总面积为1694.8 km^(2),占比55.5%,在浅山区、川水区和脑山区各自区域占比分别为87.11%、60.73%和7.59%;②乐都区综合灾害易发风险等级与人口规模、人均收入分布具有显著负相关性和正向耦合性,严重失调区分别占17.58%和15.52%,对区内乡村聚落居民生命财产及生活生计造成较大威胁;③乐都区乡村聚落空间优化可分为32个搬迁撤并型、117个优先整治型、163个防治拓展型和42个集聚提升型,具体优化建议可为西部高原山区国土空间安全提升和助力乡村振兴提供依据和参考路径。

Natural disasters risk assessment is the basic factor to measure the carrying capacity of resources and the suitability of land development.Taking Ledu,Haidong as the research area,we propose two-layer weight module to determine the weight of disaster types and hazard factors by the frequency statistics and optimized AHP method,and then get the disaster risk map and their topological characteristics by GIS.The weight of single disaster is got by the ratio of single disaster occurrence times in total comprehensive disasters.The weight of hazard factors is calculated by the optimized Analytic Hierarchy Process method.Comprehensive disaster risk level distribution map and its relationship with population,economy is obtained by spatial interpolation and superposition analysis.The results show that:(1)The total area of extremely high risk area and high risk area is 1694.8 km^(2),accounting for 55.5%of the whole county,87.11%,60.73%and 7.59%in the Qianshan area,Chuanshui area and Naoshan area.(2)The level of comprehensive disaster risk in Ledu has significant negative correlation and positive coupling with population size and per capita income distribution.The severely unbalanced areas are accounting for 17.58%and 15.52%.Comprehensive disaster risk has a serious impact on the rural residents’s life,property and livelihood.(3)The spatial optimization of rural settlements in Ledu can be divided into 4 categories:combined migration,prioritized renovation,in-situ prevention and clustered promotion.The number of each category is 32,117,163,42.The specific optimization suggestions can be planning basis and reference for the improvement of land security and the promotion of rural revitalization in the western plateau counties.The experimental results show that the method is practical.It can comprehensively analyze the disaster types in the study area,and the spatial optimization suggestions are feasible and reasonable.This method can be extended to other regions of the country,other themes of space optimization problems and the integration of different thematic space optimization results.