广东沿海陆地地质灾害及其防治对策

通过典型地质灾害的调查以及对其控制条件和诱发因素的分析表明 ,广东沿海的强震多出现于NEE活动断裂与NNW、NW向活动断裂交汇部位附近。在工程和经济活动剧烈的丘陵、河流沿岸、交通线和城镇区为水土流失、崩塌和滑坡斜坡灾变的多发区 ,降雨制约斜坡灾变的机率。地裂缝与胀缩土活动相关 ,雨季与旱雨季的交替变化是地裂缝发生的主要原因。岩溶塌陷和地面沉降均与超采地下水有关。三角洲和滨海平原软土区构成了工程建筑非稳定地基。地质灾害防治应以保护自然生态环境为主。丘陵区应进行植树种草 ,涵养水土 ,防止或抑制坡面侵蚀 ;沿海平原区 ,应合理开发利用地下水资源 ,保持地下水动态平衡。同时 ,应合理制定城镇规划 ,对重大工程建设场应开展地质灾害风险评估和地质灾害监测、预报工作。

Geological Hazards and Their Countermeasures in the Land along the Guangdong Coast

Based on the field investigation and analyses of the control factors of the geological hazards in the land along the Guangdong coast, this paper indicates that intense earthquakes occurred in this zone are closely related to intersections between the NEE-trending active faults and NE-trending active faults or NW trending active faults. Hill slopes and river banks, transpotation lines and towns, where anthropogenic disturbance into topsoils and surfaceprocesses are very intense, cause the occurrence of soil erosion, landslips and landslides. Their occurrence probabilities in time and space are controlled by rainfall intensity. The occurrence of the ground fissures in the Leizhou Peninsula are much associated with the chacteristics of swelling-shrinking soils,which is promoted by the alternations between dry seasons and rainy seasons. The occurrence and development of karsts sinks and ground sinks are triggered mainly by the excessive exploitation of the underground water, and the soft soil layers developed in the delta and coastal plains usually caused groundsill stability to be fainted. The control of the geological hazards in the area is dominated by the local eco-environment protection. In the hill area with planting and grassing activities on hill slopes control the occurrence and development of slope erosions and in coastal plains with the rational development and utilization for underground water resources will keep it a dynamic equilibrium. Simultaneously, rational planning for the development of the towns, keeping the large-scale engineering construction off the high risk zone of the geological hazards and setup off monitoring and predicting systems for the geological hazard activities around the life engineering are all practical.