Coastal aquifers serve as major sources for freshwater supply in many countries around the world, especially in arid and semi-arid zones. Many coastal areas are also heavily urbanized, a fact that makes the need for freshwater even more acute. Coastal aquifers are highly sensitive to disturbances. Inappropriate management of a coastal aquifer may lead to its destruction as a source for freshwater much earlier than other aquifers which are not connected to the sea. The reason is the threat of seawater intrusion. In many coastal aquifers, intrusion of seawater has become one of the major constraints imposed on groundwater utilization. As sea water intrusion progresses, existing pumping wells, especially those close to the coast, become saline and have to be abandoned. Also, the area above the intruding seawater wedge is lost as a source of natural replenishment to the aquifer. Despite the importance of this subject, so far there does not exist a book that integrates our present knowledge of seawater intrusion, its occurrences, physical mechanism, chemistry, exploration by geo physical and geochemical techniques, conceptual and mathematical modeling, analytical and numerical solution methods, engineering measures of combating seawater intrusion, management strategies, and experience learned from case studies. By presenting this fairly comprehensive volume on the state-of-the-art of knowledge and ex perience on saltwater intrusion, we hoped to transfer this body of knowledge to the geologists, hydrologists, hydraulic engineers, water resources planners, managers, and governmental policy makers, who are engaged in the sustainable development of coastal fresh ground water resources.

Vol. 2: Técnicas de evaluación de la intrusión marina. Estado de la intrusión marina en los países mediterráneos.

Groundwater constitutes an important component of many water resource systems, supplying water for domestic use, for industry, and for agriculture. Management of a groundwater system, an aquifer, or a system of aquifers, means making such decisions as to the total quantity of water to be withdrawn annually, the location of wells for pumping and for artificial recharge and their rates, and control conditions at aquifer boundaries. Not less important are decisions related to groundwater qUality. In fact, the quantity and quality problems cannot be separated. In many parts of the world, with the increased withdrawal of ground water, often beyond permissible limits, the quality of groundwater has been continuously deteriorating, causing much concern to both suppliers and users. In recent years, in addition to general groundwater quality aspects, public attention has been focused on groundwater contamination by hazardous industrial wastes, by leachate from landfills, by oil spills, and by agricultural activities such as the use of fertilizers, pesticides, and herbicides, and by radioactive waste in repositories located in deep geological formations, to mention some of the most acute contamination sources. In all these cases, management means making decisions to achieve goals without violating specified constraints. In order to enable the planner, or the decision maker, to compare alternative modes of action and to ensure that the constraints are not violated, a tool is needed that will provide information about the response of the system (the aquifer) to various alternatives.

This Special Issue presents the work of 30 scientists from 11 countries. It confirms that the impacts of global change, resulting from both climate change and increasing anthropogenic pressure, are huge on worldwide coastal areas (and critically so on some islands in the Pacific Ocean), with highly negative effects on coastal groundwater resources, which are widely affected by seawater intrusion. Some improved research methods are proposed in the contributions: using innovative hydrogeological, geophysical, and geochemical monitoring; assessing impacts of the changing environment on the coastal groundwater resources in terms of quantity and quality; and using modelling, especially to improve management approaches. The scientific research needed to face these challenges must continue to be deployed by different approaches based on the monitoring, modelling and management of groundwater resources. Novel and more efficient methods must be developed to keep up with the accelerating pace of global change.

This unique volume offers an up-to-date overview of all the main aspects of groundwater in the Nile Delta and its fringes, as well as latest research findings. The themes covered include: · Nile Delta aquifer formation and its characteristics · The use of the groundwater in the Nile Delta and its implications · Sedimentology and hydrogeophysical characteristics · Groundwater investigations and aquifer characterization using current direct resistivity and induced polarization · Groundwater contamination and degradation · Saltwater intrusion and its control · Delineation of groundwater flow and seawater intrusion using various techniques, including one-dimensional subsurface temperature profiles, geoelectrical resistivity, and integrated subsurface thermal regime and hydrogeochemical data · Modeling of groundwater and of saltwater intrusion in the Nile Delta aquifer · Excessive pumping and groundwater quality assessment for irrigation and drinking purposes · Groundwater management for sustainability in the Nile Delta. The volume appeals to postgraduate students, researchers, scientists, professionals, decision makers and planners.

This book aims to clarify the issue of groundwater in coastal saline environment management. It serves as a reference to scientists, engineers, and decision makers who might use it to improve resource management practice and cooperation in the delta region. It specifically covers the nature and extent of the aquifers in the coastal saline tract of Mahanadi Delta, India. The book scientifically delineates and classifies the aquifers, illustrates the geology, hydrogeology, geomorphology, geophysics, geometry, and water quality of the different aquifers, and explores the nature and extent of seawater intrusion in the different aquifer systems.

This book is an essential reference for engineers and scientists working in the field of turbulence. It covers a variety of applications, such as: turbulence measurements; mathematical and numerical modeling of turbulence; thermal hydraulics; applications for civil, mechanical and nuclear engineering; environmental fluid mechanics; river and open channel flows; coastal problems; ground water.