基于地质灾害危险性评价的建设用地布局规划

":5.12"汶川地震诱发了都江堰市许多新的地质灾害,恢复重建工作不断遭遇一系列复杂的地质环境问题。文章根据重灾区都江堰市震后地质地理环境特征,优选出坡度、震后地质灾害密度、工程岩组、线性构造密度、土地利用现状、河网密度等6个评价指标,建立分级标准;利用GIS技术对空间数据的采集和分析功能,结合数理统计的方法原理,对都江堰市进行地震诱发地质灾害危险性定量评价。经过精度验证,结果显示震后都江堰市地质灾害高危险区和较高危险区占土地总面积的15.8%,主要位于"5.12"特大地震发震的龙门山推覆构造带的前山推覆构造带上;地质灾害中等危险区分布较广,占总面积的15.8%;地质灾害低危险区和较低危险区分布最广,占总面积的68.4%,主要分布在坡度平缓、植被发育、坚硬或半坚硬的岩组地区,将评价结果与新一轮土地利用总体规划的城镇用地布局、农村集中居住区点位叠加,科学准确地揭示出研究区震后建设用地区域地质灾害空间分布规律,从空间上对建设用地的安全布局进行了预警,为新一轮土地利用总体规划建设用地布局规划方案提供科学的参考。

Construction Land Layout Planning Based on the Geo-hazard Risk Assessment

"5.12" Wenchuan Earthquake has induced many new geo-hazards in Dujiangyan City,and restoration and reconstruction have encountered a series of complex geological environment.Based on the geological environment characteristics of Dujiangyan City after the earthquake,this paper optitmizes six assessment factors including slope,geo-hazards density,petrofabrics,linear structure density,present land-use situation,drainage network density,and establishes grading standards.The paper also quantitatively evaluates the geo-hazard risk triggered by the earthquake of Dujiangyan,which uses GIS technology to collect the spatial data and its analysis capabilities,combined with the principle of mathematical statistics.After accuracy verification,the results show that geo-hazard highest-risk areas and higher-risk areas of Dujiangyan after the earthquake account for 15.8% of the total land area,which is mainly located in front range of Longmen Shan nappe structure zone,the seismogenic zone of the "5.12" Earthquake.Medium-risk areas is widely distributed with 15.8%.Lowest-risk areas and lower-risk areas owns 68.4%,which is mainly located in the gently sloping,vegetation growth,semi-hard or hard rock group region.It also makes a superposition of this results and urban land,rural residential areas of the land use planning,and scientifically and accurately reveals the spatial distribution of geo-hazard,in order to make a early warning for safe layout planning of construction land and provide scientific evidence for a new round of overall land use planning.