Evaluation Of Geological Disasters In Tianjin

Hazards evaluation and forecast work of regional geological disaster is an important element in prevention and control of that disaster, and also is important to ensure the safety of life and property, as well as the benefits of economy, society and environment. For a certain region, geological disasters are usually occurred together. Therefore, a comprehensive evaluation of geological disaster is made upon the basis of each disaster, analyzing correlations among several disasters, confirming the impact for environment, and hazards in the disaster area.Internal factors and external factors jointly initiate geologic disaster. Geological disasters spread widely in Tianjin. They are mainly natural geological disasters occurred after geological process. However, geological disasters caused by human activities can further destroy geological environment, becoming crucial issues. Based on analysis of historical materials and disaster conditions, main disasters in Tianjin are: earthquakes, surface subsidence, collapse, landslide, debris flow, soft soil ground, coastal erosion, etc. Among them, small collapse, landslide and debris flow are mainly occurred in northern mountainous area, and surface subsidence is mainly distributed in southern plain.Small collapse, landslide and gully debris flow are mainly occurred in northern mountainous area, in which small collapse is mostly occurred. And human activities are the main causes of such disasters. To protect environment, mines of metal and non-mental in mountainous area are shut down in succession. What’s more, vegetated areas are enlarged yearly. With gentle slope of the mountains, geological disasters have little hazards.Southern plain area is with flat terrain. Multistage funnel is formed due to surface subsidence under specific hydrogeology and engineering geology. Apart from Jixian District and Baodi District, most plain in the south of Baodi District settles 10mm/a or more. So we say that geologic disaster in plain region is mainly surface subsidence.Geological disasters are mainly concentrated in southern area, especially in Jinnan District, Xiqing District and Jinghai County, which are caused by deploring underground water. Therefore, the primary task at present is to control the scale of underground water.