基于GIS的潜势度地质灾害预警预报模型研究——以浙江省温州市为例

Potential Degree Index Model of Early Warning System for Geological Hazards:A Case Study of Wenzhou in Zhejiang Province

受台风和暴雨的影响,温州市地质灾害频发,是浙江省地质灾害最严重的地区。该文以温州市为例,提出基于GIS的潜势度地质灾害预警预报模型。该模型输入降雨因素和非降雨因素两大类变量。其中,非降雨因素采用潜势度描述点状预警单元发生地质灾害的潜在能力,根据地形、地貌和地质等非降雨因素的重要程度归结为无量纲的潜势度;降雨因素根据灾害和地域的不同,通过降雨阈值归结为无量纲的降雨等级。两类输入变量经过预警判据矩阵输出相应的预警级别,插值后形成由点状到面状的预警结果。系统预警预报模型采用潜势度模型,使用ArcObjects技术在ArcGIS地理信息系统中集成开发,提供预警计算结果表格、实时预警地图和预警短信等功能,大大提高了地质灾害预警和预报的精度,为地质灾害防灾工作提供了实时、可靠和科学的技术支持。

Wenzhou is the most serious geological hazard area in Zhejiang Province,with a large area of mountain,a frequent occurrence of geological hazards due to typhoons and rainstorms.In this paper,Wenzhou was taken as a case study for the potential degree index(PDI)model of the early warning system for geological hazards.The early warning model of geological hazards have two major categories of variables:the rainfall factors and the non-rainfall factors.The non-rainfall factors used the PDI to describe the potential probability in a point-shaped warning unit and were transformed to non-dimensional form of PDIs based on the terrain,geomorphology and geology of landslide or debris flow hazards.The rainfall factors applied rainfall thresholds to generate non-dimensional degree of rainfall.Finally,the above variables were inputted into a criterion matrix to generate the degree of early warning,and to give area-shaped warning results after interpolation.Applying the PDI model proposed in the pap ery GIS-based early warning system implemented by ArcObjects technique has been established to achieve a real-time prediction with susceptibility map,excel computation data and warning messages obtained as the output to help decision making in areas prone to geological hazards.