快速城市化条件下地下水开发的环境效应研究

Environmental Effects of Developing Groundwater in Xuzhou City During Rapid Urbanization

赋存于寒武系和奥陶系灰岩中的岩溶水是徐州市的主要供水水源.1978年以来,随着经济的发展和快速城市化,市区岩溶地下水开采量逐年增加;而且城市西北郊煤矿的开采疏排水活动也导致大量的地下水流失.上述两种作用导致徐州市岩溶地下水位的持续下降,降落漏斗面积逐年增加,增强了地下水系统的脆弱性,诱发了诸如局部水资源枯竭、水质恶化、地下水污染和岩溶塌陷等一系列环境问题.这些环境问题具有系统性和连锁性的特征,已严重影响了城市的发展质量,增加了城市供水的风险.根据各个环境要素演化关系,本文建立了城市化条件下地下水开发的环境效应概念模型,并提出了岩溶地下水保护的措施建议.

In Xuzhou City,aquifer in Ordovician and Cambrian limestone is a main source of water supply, there are 527 wells in urban area to develop karst groundwater, yielding up to 30 000 m^3 a day. Since 1978, urbanization and industrialization of Xuzhou City have been going at a greatly accelerated pace. Overexploitation of karst groundwater has caused the drawdown of piezometric level and the enlargement of depression cone area year after year. These changes have aggravated the vulnerability of karst groundwater system and induced some environmental problems,such as depletion of water resource, water quality deterioration, groundwater contamination and karst collapse. According to the evolutive relation among all environmental factors, a conceptive model of environmental effect for groundwater exploitation under the urbanization condition is established, and some measures for protecting karst groundwater are suggested.