北部湾广西海岸带地质环境综合监测进展及成果

广西沿海地处我国东南沉陷地震带，地震活动比较活跃，热带气旋影响频繁，地质环境和灾害风险性问题日益突出，但缺乏有效的海陆联测手段和长期监测资料。通过综合物探、地质取样、海水取样及海流剖面测量等综合技术手段，首次在北部湾广西近岸进行了5年次的海洋地质环境综合监测，对地形、地层、沉积物、矿物、重金属以及水质要素等进行了分析和评价。结果显示: 广西海岸带环境要素时空变化较大，滩面平衡点摆动，冲淤变化较大; 海水污染物主要是营养盐、石油类和部分重金属; 局部岸段人为改造明显，水质总体趋好与加大环境治理力度有关; 海岸脆弱性较高，灾害的突发性风险增加，需要进一步加强监测工作。

Progress and achievements of integrated geo-environmental monitoring along Guangxi coastal zone,Beibu gulf

The Guangxi castal zone is located in the earthquake subsidence belt of southeastern China, in which the earthquake is rather active, and the tropical cyclone is rather frequent. The geo-environmental problem and geo-hazard risk have become more serious, but there are insufficient land-sea synchronously-observed methods and long-term monitoring data to prevent the burgeoning crisis. A set of integrated geophysical exploration, geological sampling, seawater sampling and ocean current survey are used to monitor the geo-environment along the Guangxi coastal zone of Beibu gulf during the last five years, and the auunal variation of shallow strata, bottom sediments, detrital minerals, heavy metals and seawater elements are analyzed and assessed for the first time. The results show that the spatial and temporal variations are significant, the balance point change of beach surface is distinct, and the scouring and silting change is great. The seawater pollutants are mainly composed of nutrition salt, oil and heavy metals, and the geo-environment of some segments of the Guangxi coastal zone is changed by human. The water quality is related with local environment improvement. The vulnerability and the risk of geo-harzard should be paid more attention and need further monitoring.