城市地面沉降的灾害链特征——以天津市为例

Disaster Chain of Urban Land Subsidence in Tianjin

以20世纪60—80年代天津地区地面沉降灾害的发展为例,讨论了城市地面沉降灾害的特征,分析了地面沉降引发的次生灾害及其防治问题。结果表明,城市地面沉降灾害主要具有缓释特征、不可逆特征、罪罚特征和灾害链特征,城市地面沉降能够破坏市政设施,引发城市内涝和河流泄洪能力降低,造成地下水质和地质环境恶化,使海平面上升,沿海风暴潮加剧,同时还能造成海拔标高损失等。地面沉降所造成的损失是个巨大的灾害链,损失应当包括硬件和软件,也应当包括当前和远景,以致更深层次的影响。另外,缓释、不可逆的灾链特征对经济发展的布局、远景规划和投资环境影响不可低估;生态地理环境灾害链的影响,其效益损失更难于估计。地面沉降是城市灾害系统中的重要环节,也是城市防灾减灾的重要内容。地面沉降灾害的防治,应当是经济、环境、行政、立法,甚至教育、宣传等各个方面相结合的系统工程。

Taking the development of land subsidence disaster from 1960＇s to 1980＇s in Tianjin as an example, the characteristics of land subsidence disaster are discussed, and their secondary disaster and prevention problem are analyzed. The results show that, land subsidence disaster has the following characteristics： sustained-release, irreversibility, crime and punishment, and disaster chain. Land subsidence can destroy city establishment, induce urban waterlogging and reduce the discharging capacity of rivers, lead to groundwater quality and geological environment deterioration, raise the sea surface, intensify the inshore storm, and bring elevation height loss. The loss from land subsidence is a big disaster chain, including hardware and software, current, future and even further influence. In addition, the influences of sustained-release and irreversibility on economic development＇s layout, long-term planning and investment environment cannot be underestimated. The influences of ecological and geographical environment disaster chain are more difficult to be estimated. The land subsidence is an important link in urban disaster system, and also is an important content in urban disaster prevention and reduction. The land subsidence disaster prevention must be a system engineering combining economy, environment, administration, legislation, and even education and propaganda.