【作者】 彭青华；

【导师】 韩再生；

【作者基本信息】 中国地质大学（北京） ， 水文学及水资源， 2007， 硕士

【摘要】 地面沉降是指自然和人为作用下,由于地壳表层土体压缩而导致区域性地面标高降低的一种环境地质现象,它具有生成缓慢、持续时间长、影响范围广、成因机制复杂和防治难度大的特点,是一种对城市规划建设、经济发展和人民生活构成威胁的地质灾害。目前,国内外对地面沉降问题的研究,主要着重于对抽取地下液体而引起的区域性地面沉降的研究。沧州市位于河北平原东部,濒临渤海,地理位置优越,发展前景广阔,是全国著名的化工城市。然而沧州市又是环渤海地区严重缺水城市之一,其地面沉降始于20世纪70年代初期,当时沉降量只有9mm。随着地下水开采量增大,地面沉降量也随之不断增加,1980年中心累积沉降量272mm,沉降速率27.2mm/a;至1990年中心累积沉降量1131mm,沉降速率85.9mm/a,比上一时段增加了58.6mm/a;至2001年沉降速度已达100.45mm/a,中心累积沉降量达到2236mm,2005年中心累计沉降量已达2457mm,已成为我国地面沉降最严重城市之一,其影响和破坏愈演愈烈。研究区由于大量抽取地下水,使得承压层中的粘土夹层及上覆粘土释水,引起土层压缩,导致地面沉降。本文根据研究内容确定了研究区的模拟范围,然后根据该研究区实际的工程地质及水文地质条件确立了该区地质概念模型,确立了模型的边界条件,采用三维有限差分地下水流模型-Processing Modflow及其携带的IBS程序包对该研究区各含水层水位、地面沉降进行同步模拟,经过多次调参,选取了恰当的水文地质参数,建立了该区的地下水位-地面沉降耦合模型,以2005年开采水平为基础,结合市区城市化建设发展规划,运用所建立的地面沉降模型,预测了沧州市2015年的地面沉降情况。最后,对防止沧州市地面沉降的严重化提出了些意见,例如开辟新水源,加强管理力度,建立监测网络等。更多还原

【Abstract】 Land subsidence is an important problem. There is natural land subsidence, and also many human activities can induce several kinds of land subsidence hazards. Many kinds of human activities can induce land subsidence, such as groundwater withdrawal, mineral resources exploitation, building of skyscrapers and the exploitation of underground space. The land subsidence is very serious in Hebei plain of China, especially in Cangzhou city. In the region of Cangzhou city, the land subsidence has amounted up to 1131mm in 1990, and reached 2236mm in 2001.As the data says, the rate of land subsidence is very fast.Based on the actual hydrogeology and engineering geology condition of the area, a concept hydrogeological model is built first. Pumping from the confined aquifer, the clay stratum that is in and above the confined aquifer releases a large amount of water, resulting in the compaction of soil layer called land subsidence. Adjusting the hydrogeological parameters for many times and choosing the best ones. The Modular three-dimensional groundwater flow model--MODFLOW and another modular program-IBS are applied to simulate the water table and land subsidence synchronously and build the mathematical model of water exploitation-land subsidence. And based on this model a prediction of the situation of land subsidence is made up to 2015.Finally, some advices have been put forward for preventing the development of the land subsidence, such as looking for new water resources, strengthening administration, building the land subsidence measurement network and so on.更多还原