基于MODFLOW数值模拟法的地下水饮用水源保护区划分

Division of Groundwater Protection Areas of Drinking Water Based on MODFLOW Numerical Simulation

我国城乡居民饮用水安全现状不容乐观,饮用水源污染已经成为较突出的社会问题,其中地下水饮用水源污染更为突出。饮用水源保护区划分是保证水质安全的重要措施,饮用水源保护区划分方法较多,其中数值模拟法能客观并详细地描述含水层结构与水文地质条件,适用于各种背景的地下水水源研究。本文以崇州市城区饮用水源为例,采用MODFLOW软件建立地下水渗流场,应用MODPATH对水源地抽水井进行粒子逆向示踪模拟,根据不同的时间标准确定一、二级保护区范围,并结合区域水文地质条件和地标、地界特点确定各级保护区的界线。

The current situation of drinking water safety is not optimistic for urban and rural residents in China, while the pollution of drinking water sources has been a prominent social issue. Moreover, the groundwater pollution of drinking water is more serious. The division of drinking water protection areas is one of the important measures to ensure the safety of water quality. Among the numerous division methods of drinking water protection areas, numerical simulation can specified the aquifer structure and hydrogeological conditions objectively, and so it can be applied to various researches on groundwater sources. Based on a case study of Chong Zhou City, this paper established the local groundwater seepage field with MODFLOW and simulated the inverse tracking of particles from the pumping wells with MODPATH. The divisions of first and second grade protection areas of drinking water were determined on the basis of different time standards and the boundaries were also determined depending on local hydrogeological and topographic conditions.