基于地质灾害的多样性及其变化的随机性和非稳定性特点,本文综合利用数学算法和GIS技术,设计了地质灾害预警模型,分析了诱发地质灾害的地形、地貌、气象、水文等几方面的因素,并根据这些因素的特点,选取不同的样本对其进行量化处理,运用主成分分析法,计算了各个因素导致地质灾害发生的权重指数及各监测站点的易发级别。在此基础上,基于GIS技术、采用泰森多边形法等将站点的易发级别转换成面的易发级别,运用日降雨量、降雨强度等指标计算出地质灾害发生的概率,通过区域化易发等级图与降雨图的叠加分析,采用地质气象偶合方法,实现了地质灾害预测。在某省案例区的研究表明,本研究设计的地质灾害预警模型具有较高的预警精度(预警结果80%符合实际情况)。
This paper presents a design of a geo - hazard early warning model. It can analyze the influence factors including terrain, physiognomy, hydrology, etc. It is based on the features of variety, randomicity and variability of geohazards and use the map algebra and GIS technologies. Considering the features of influential factors, the principal components are selected to quantitatively identify and measure the influence of each factor. And then the levels of potential hazards are calculated by the data and information collected from the station. On this basis, using the Thiessen interpolation method, the surface data are generated with the levels of hazards according to the site - based hazards information. Based on the daily effective rainfall and intensity records, the occurrence of probability of geo - hazard is calculated. After overlaying the level map of hazards, the surface data with the levels of hazards and with rainfall map, the occurrence of geo - hazard can be predicted based on the weather confidence method and the functionality of geo - hazard early warning model can be realized. The case study in Guangdong province shows that the geo - hazard early warning model can predict the occurrence of geo - hazards with high spatial resolution. The framework itself is logic while the predicted results are reliable. So in some sense, this method could be extended to other case studies. The research results in Guangdong are bearing more significance for the guideline ofpreventing and controlling the occurrences of geo - hazards.