Sinkholes Due to Groundwater Withdrawal in Tazerbo Wellfield, SE Libya
Sinkholes Due to Groundwater Withdrawal in Tazerbo Wellfield, SE Libya
复制标题
利比亚东南部 Tazerbo Wellfield 因地下水抽取而出现天坑
作者：
Nawal Alfarrah;G. Berhane;Abdelrahim Hweesh;K. Walraevens
利比亚东部的沙漠是撒哈拉最干旱的地区之一。“大河工程”（GMRP）正式启动。它每天将数百万立方米的水从沙漠井田输送到沿海城市，80%以上的人口居住在沿海城市。Tazerbo井田是GMRP中设计的井田之一，通过地下管网向利比亚东海岸输送水。Tazerbo井场由108口生产井组成；每口井的泵送速度为100l /s。计划从所有井中抽取的地下水总量为100万立方米/天。深层砂岩含水层（努比亚砂岩）被厚厚的泥岩-粉砂岩含水层覆盖，并被大量抽水。由于高开采，含水层和含水层的细粒沉积物可能被压实，导致地面沉降。自2004年开始从井田抽水以来，Tazerbo地区已经出现了当地的天坑。这些陷坑主要是由于抽取地下水导致测压水头下降造成的。本文基于108口生产井和23口观测井的物性参数，对利比亚南部Tazerbo井场努比亚砂岩含水层大量抽取地下水的效果进行了水文地质调查。
The desert of eastern Libya forms one of the most arid regions of the Sahara. The Great Man‐Made River Project (GMRP) was established. It transports millions of cubic meters of water a day from desert wellfields to the coastal cities, where over 80% of the population lives. The Tazerbo Wellfield is one of the wellfields designed within the GMRP, delivering water to the eastern coast of Libya through an underground pipe network. Tazerbo Wellfield consists of 108 production wells; each well was designed to pump 100 L/s. The planned total groundwater withdrawal from all wells is 1 million m3/d. The deep sandstone aquifer (Nubian sandstone) is covered by a thick mudstone‐siltstone aquitard and is being heavily pumped. The aquifer and fine‐grained sediments of the aquitard may be compacted resulting in land subsidence as a result of high exploitation. Local sinkholes have developed in the area of Tazerbo since the start of the pumping from the wellfield in 2004. These sinkholes have been caused mainly by lowering of the piezometric heads due to the withdrawal of groundwater. In this study, a hydrogeological investigation is presented about the effect of large groundwater pumping from the Nubian sandstone aquifer in Tazerbo Wellfield, SE Libya, based on physical parameters for 108 production wells and 23 observation wells.