基于GIS和信息量模型的坡面孤石发育程度评价

Development Degree Assessment of Slope Boulder Based on GIS and Informative Model

广州市花岗岩广泛分布,由花岗岩差异风化形成的孤石非常发育,城市化的快速发展和极端强降雨天气的不断增多,导致坡面孤石崩塌灾害频繁发生,严重威胁了广州市的经济发展和城市建设。本文以广州市黄埔区为例,基于坡面孤石调查样本,分析了坡面孤石的分布规律和发育特征;选取基岩岩性、地形坡度、坡向、坡面曲率、高程、断裂距离和植被覆盖率等7个影响因子,采用信息量模型和ArcGIS的空间分析功能,开展研究区的坡面孤石发育程度评价,将研究区坡面孤石发育程度划分为4个等级:强发育区、中等发育区、弱发育区和不发育区。将坡面孤石发育程度分区与调查样本分布进行对比分析,结果表明,坡面孤石发育程度分区具有较高的准确性。

Granite is widely distributed in Guangzhou, and boulders formed by differential weathering of granite are very developed. The rapid development of urbanization and the continuous increase of extreme heavy rainfall weather have led to the frequent occurrence of slope boulder collapse, which has seriously threatened the economic development and urban construction of Guangzhou. Taking Huangpu of Guangzhou as an example, based on the investigation samples of slope boulders, this paper analyzes the distribution law and development characteristics of slope boulders, and seven influencing factors such as bedrock lithology, topographic slope, slope direction, slope curvature, elevation, fracture distance and vegetation coverage are selected to evaluate the development degree of slope boulders in the study area by using the informative model and the spatial analysis function of ArcGIS. The development degree of slope boulders in the study area is divided into four grades: strong development area, medium development area, weak development area and undeveloped area. By comparing the development degree zoning of slope boulders with the distribution of survey samples, the results show that the development degree zoning of slope boulders has high accuracy.