摘要
由于我国自然地理、地质构造条件复杂，地质灾害严重。据地质灾害的物质组成、动力作用、破坏形式和破坏速率，初步将我国地质灾害分为10大类38亚类。我国地质灾害具有明显的地域特征和区域变化规律。由于人口增长，经济发展的双重压力，导致我国地质灾害灾种增多、频度增高、危害性增大，生态环境急剧恶化。
China is a large country with numerous population and vast territory. DUe to the complexity of natural geography and geological structure, various natural disasters occur frequently, which cause serious loss of lives and property, and become one of the restricted factors for society and economic development. Among various natural disasters, geo-hazards occupy an outstanding place in terms of its resulting much more Personnel casualties, large economic damages and itS happening characters of suddenness, and in groups, high frequent and lashng influence. According to statistics,the direct economic loss caused by 15 main geo--hazards is about 27 billion--Yuan,which accounts for one quarter of the total caused by various natural disasters .On the basis of geo--hazards already happened, they in China are divided into 10big categories and 38 sub-categories in the material component, motive power,destructive form and damage rate.Restricted by the landform and geomorphology, geologic condition, latitude division, the geo-hazards in China possess obvious regional characters and varying patterns. The basic characters of geo-hazard development are many categories,complete varieties and large damage, which is beyond compared with any other country in the world. In the history, the Chinese people have made fruitful efforts ongeo-hazard mitigation, which conserves the development of agricultUre, industry,transportation ; the construction of cities and mines; the safety and operating of large water conservancy projects. But the damage of geo-hazards for people's lives and property is still very serious, and is becoming increasingly intense. The externalfactors on serious development and non--recovery after prolonged control are as follows: the irrational engineering and economic activities,over-exploitation of resource,the traditional development model of high consumption and high discharge, and being the first of pollution (destroy) and the last to control. A lot of geo--hazards are of the characters of haPPening in--groups and in correlation, which forms a disaster system or disaster chain. The result of former hazard may be the cause of the latter one. FOr example, soil erosion in the middle reaches of the Huanghe River leads to the sediment deposihon and suspended river in the lower reaches. So, in the processof geo--hazard prevention and control, not only the local renovating should beconducted on the basis of finding out its mechanism, but also it should be considered to pay attention to the overall plan and comprehensive prevention and control.The geo--hazards in China are of the periodicity of developing process andlong--term influences. The former is synchronous with meteorological Period.According to statistics, tectonic earthquakes caused by internal motive power also possess the Periodic active pattern between high frequency and low one. Landsubsidence is difficult to recover once it occurred; i. e. its development course isun--reversible. The large--area subsidence and crack occurred in the coastal cihes andeastern plains such as in Shanghai and Tianjin, have been restricting the urbandevelopment and modernized management. Its further deterioragion can be controlled by reducing the groundwater exploitation, but the original elevation can not berecovered. UP to now, it hasn't been paid sufficient attontion to its long--term influence over environment evolution, so no determined strong countermeasures have been adopted.With the population increasing, economic development and engineering activity intensifying, the geo-hazard varieties, frequency and damage are increasing. The Baocheng, Baolan, Chengkun railways are the main transportation lines constructed in mountainous area. DUe to artificial slope--cutting and loading, the natural equilibrium of rock and soil was destroyed, which has resulted in the falling, landslide, and mud--rock flow to occur frequently. Sometimes the traffic was broken off. Even the safeguard cost exceeds the construction one. Soil erosion and land desertification,which leads the ecological environ
出处
《第四纪研究》
CAS
CSCD
北大核心
1999年第3期208-216,共9页
Quaternary Sciences
