渤海海域地质环境稳定性定量评价

Quantitative evaluation of the geological environment stability in the Bohai Sea

渤海地理位置优越,海洋经济发展迫切需要地质环境资料的支撑,现有研究通常分海区开展,缺乏实测资料支持的系统性研究。基于2008—2016年海洋区域地质调查环境地质因素的相关资料,通过网格化处理,量化渤海海域主要环境地质因素的特征参数,建立了以海底地形或底质环境变化类、地层不均衡类、活动构造类为主要评价指标的地质环境稳定性评价指标体系,采用专家-层次分析定权法和模糊数学评价方法对研究区地质环境稳定性进行定量评价研究。结果显示,渤海海域依据地质环境稳定性可划分为差等、较差、中等、较好、优等5级,大部分海域地质环境稳定性总体较好,地质环境稳定性较差的海域占比10.00%,尤其是黄河三角洲周边海域,不稳定环境地质因素活动断层、地震震中、浅层气及与潮流相关的环境地质因素较为集中,危险性较大。研究结果对渤海海域自然资源的开发利用、生态环境保护等具有重要的应用价值,相关定量评价方法可为中国海洋环境地质研究提供借鉴。

The Bohai Sea has a superior geographical position.The development of its marine economy asks urgently for the support of geological environment data.Most present studies usually are concentrated on some individual seas,and lack of the systematic thinking of different seas using actual testing data.Based on the available data of environmental geological factors in marine regional geological survey since 2008,The Bohai Sea was divided into grid cells and the characteristic parameters of its main environmental geology factors were quantified.An indicator system of the evaluation of the geological environment stability was established based on the topographic or ground environmental change,uneven bearing stratum,and active tectonics.The geological environment stability in the study area was quantitatively evaluated by using expert-analytic hierarchy process and fuzzy mathematics.Results suggest that the geological environment stability in Bohai Sea was divided into five grades:poor,relatively poor,medium,relatively good,and excellent.The stability in most of Bohai Sea is generally in good condition at the present.The regions in poor and relatively poor grades of stability accounts for 10%,particularly in the adjacent area of the Yellow River Delta,where the unstable environmental geology factors active faults,earthquake epicenter,shallow gas and the factors related to the tide are comparatively dense,with relatively large hazard.This study is valuable for future exploitation and utilization of natural resources,eco-environment conservation in Bohai Sea.Meanwhile,the quantitative evaluation method of this study provided a reference for the study of marine environmental geology.