tailieunhanh - COASTAL AQUIFER MANAGEMENT: monitoring, modeling, and case studies - Chapter 12 (end)

Điều tra địa chất thuỷ văn và mô phỏng bằng số của dòng nước ngầm trong tầng nước ngầm karst của Northwestern Yucatan, Mexico Các tầng nước ngầm ở tây bắc Yucatan có chứa một ống kính nước ngọt nổi trên nêm một dày đặc hơn nước muối nước thâm nhập vào hơn 40 km trong đất liền [Quay lại Hanshaw, 1970; Durazo et al, 1980, Back và Lesser, 1981; Gaona et al, 1985. ; Perry và cộng sự, 1989]. Gần đây, nó đã được chỉ ra rằng sự thâm nhập hơn 110 km [Perry và cộng sự, 1995;. Steinich và. | CHAPTER 12 Hydrogeological Investigations and Numerical Simulation of Groundwater Flow in the Karstic Aquifer of Northwestern Yucatan Mexico . Marin . Perry . Essaid B. Steinich 1. INTRODUCTION The aquifer in northwestern Yucatan contains a freshwater lens that floats above a denser saline water wedge that penetrates more than 40 km inland Back and Hanshaw 1970 Durazo et al. 1980 Back and Lesser 1981 Gaona et al. 1985 Perry et al. 1989 . Recently it has been shown that the penetration is more than 110 km Perry et al. 1995 Steinich and Marin 1996 . The aquifer which is unconfined except for a narrow band along the coast Perry et al. 1989 is the sole freshwater source in northwestern Yucatan. Development of industry and agriculture and other land use changes pose a potential threat to the quantity and quality of freshwater resources in the Yucatan Peninsula. This chapter reports field investigations used for the construction of a groundwater flow model developed for the purpose of increasing our understanding of the groundwater system and estimating the hydraulic response to aquifer stresses. The groundwater flow model is also useful in detailed studies of saltwater intrusion and the tracking of contaminants from industrial or agricultural sources. Ultimately it can serve as a basic information source for local groundwater resources management. The objectives of this research are to 1 describe the hydrogeologic system for northwestern Yucatan including the identification of hydrogeologic boundaries 2 determine whether it is possible to simulate groundwater flow using a sharp interface model in this karstic aquifer and 3 examine how the system responds to stresses such as breaching of the coastal aquitard. 2004 by CRC Press LLC 2. PREVIOUS STUDIES The hydrogeology of the eastern coast of the Yucatan Peninsula has been extensively studied by Back and Hanshaw 1970 Weidie 1982 Back et al. 1986 Stoessell et al. 1990 and Moore et al. 1992 . The hydrogeology of the