西藏昌都镇地质灾害发育特征及防治对策

昌都镇位于澜沧江上游“三河一江”地带(即昂曲、扎曲、色曲、澜沧江)。地质构造条件复杂,气候较恶劣,昼夜温差大,物理风化强烈,植被稀疏,地质灾害发育。该区是藏东的政治、经济、文化中心。随着地区的经济发展,其城镇建设与地质灾害之间的矛盾日益突出。调查研究显示昌都镇发育地质灾害33处,其中崩塌16处,占灾害点总数48.5%,主要发育于路堑边坡和河流下切侧蚀形成的自然边坡;滑坡13处,占灾害点总数的39.4%,且90%为土质滑坡,多与人类工程活动有关;泥石流4处,占灾害点总数的12.1%,以中小型为主。文章总结了昌都镇崩塌、滑坡和泥石流灾害的发育分布特征,地质灾害与地层岩性、空间位置和人类工程活动等之间的关系,以及对昌都城镇建设和发展的影响。结合调查分析提出了昌都镇地质灾害防治的总体策略———治灾、设防、治水、治坡、生态建设和加强环保意识。

Characteristic and countermeasures for geological hazards in Changdu Town, Tibet

Changdu Town is an important town in the east of Tibet.It is the centre of policy,economy and culture in changdu District.With Changdus economy progress,the contradiction between town construction and geological hazard is becoming sharper.Changdu Town lies in the upriver of Lancangjiang Rive,and three rivers pass through it,which are Angqu,Zhaqu and Sequ Rivers.For complicated geologic structure,bad climate,great difference in temperature,strong physical weathering and lack of vegetation,there are many geological hazards.The investigation shows that there are 33 geological hazards,including 16 collapses,occupying 48.5%,lying in the slope of roadside,riverside and foreland of high nature slope;13 landslides,occupying 39.4%,90% of which are soil slopes and majority of them relate to human engineering;and 4 debris flows,occupying 12.1%,belonging to little or middle type debris flow.Based on a lot of investigation,the distribution characteristic of geological hazards and the relationships between them and stratum,rock character,space position,human activity and the influence on city construction are analyzed. At last,the countermeasures to geological hazards are put forward,including treating,proofing,water controlling,proofing soil and water loss,ecology construction and strengthening environmental protect consciousness.The conclusion is drawn that fully knowing the distribution characteristic of hazards and executing systemic countermeasures are the base of guaranteeing human life and property,promoting town construction and economy progress.