珠江口近岸海域浅层地质灾害区域风险模糊评价

Regional Risk Evaluation of Shallow Geological Hazard by Fuzzy Evaluation Method in the Pearl River Estuary

珠江口地区是我国重要的经济圈,人类活动剧烈,其近岸区域地质环境复杂,区内灾害性地质因素广泛发育且类型多样。为了海底工程建设和维护的需要,对海底区域地质灾害进行风险评价,可掌握不同区域的灾害程度,有针对性的选择地质条件相对稳定的区域进行工程建设,绕避高风险不良地质地区,或在不良地质地区采取相应工程措施加以防治。本文运用模糊评价的方法,将珠江口近岸113°00′E～114°00′E,21°40′N～22°40′N的区域,按照2′×2′的网格大小划分为546个评价单元,对每个单元稳定程度逐一进行评价。评价结果表明:在研究区范围内,多数海域海床均为稳定区域,约占总评价区的58%;较不稳定区域包含该区多种地质灾害,约占研究区的25%;极不稳定区域所占范围较小,主要分布在研究区的东北和西北2个断层附近,该区域同时存在断层、洼地和浅层气,在工程建设时需着重注意。

The area around Pearl River estuary is one of the most important economic zones in China where the effect of human activities is acute.The geological environment which is complex and various hazardous geological characteristics are distributed.For the sake of submarine infrastructures’ safety,both construction and maintenance,we need to evaluate the geological hazard risk.The hazard degree of different areas can be realized.Submarine infrastructures can keep away from those high risk areas.In case those areas with high risk could not be avoided,adequate engineering measures could be taken for disaster risk reduction.Using the fuzzy evaluation method,the author divided the area between 113°00′E^114°00′E and 21°40′N^22°40′N into 546 2′×2′ squares.The results show that 58% of the research area is stable,while 25% of the research area is less stable.The distribution of unstable areas is near the northeast and northwest faults.Despite the fact that the unstable area is limited,we should pay more attention to these areas when design and construct submarine infrastructures.