In view of the rapidly expanding urban, industrial and agri cultural water requirements in many areas and the normally associated critical unreliability of surface water supplies in arid and semi-arid zones, groundwater exploration and use is of fundamental importance for logical economic development. Two interrelated facets should be evident in all such groundwater projects : (a) definition of groundwater recharge mechanisms and characteristics for identified geological formations, in order to determine whether exploitation in the long-term involves 'mining' of an es sentially 'fossil' resource or withdrawal from a dynamic supply. A solution to this aspect is essential for development of a re source management policy: (b) determination of recharge variability in time and space to thus enable determination of total aquifer input and to quantify such practical aspects as 'minimum risk' waste disposal locations and artificial recharge potential via (e.g.) devegetation or engi neering works. However, current international developments relating to natural recharge indicate the following 'problems' ; no single comprehensive estimation technique can yet be iden tified from the spectrum of methods available; all are reported to give suspect results.

Proceedings of the NATO Advanced Research Workshop on Estimation of Natural Recharge of Groundwater (with special reference to Arid and Semi-Arid Regions), Antalya, Side, Turkey, March 8-15, 1987

To face the threats to the water supply and to maintain sustainable water management policies, detailed knowledge is needed on the surface-to-subsurface transformation link in the water cycle. Recharge flux is covered in this book as well as many other groundwater issues, including a comparison of the traditional and modern approaches to determine groundwater recharge. The authors also explain in detail the fate of groundwater recharge in the subsurface by hydraulic and geologic means, in order to stimulate adapted groundwater-management strategies.

As demand for water increases, water managers and planners will need to look widely for ways to improve water management and augment water supplies. This book concludes that artificial recharge can be one option in an integrated strategy to optimize total water resource management and that in some cases impaired-quality water can be used effectively as a source for artificial recharge of ground water aquifers. Source water quality characteristics, pretreatment and recharge technologies, transformations during transport through the soil and aquifer, public health issues, economic feasibility, and legal and institutional considerations are addressed. The book evaluates three main types of impaired quality water sourcesâ€"treated municipal wastewater, stormwater runoff, and irrigation return flowâ€"and describes which is the most consistent in terms of quality and quantity. Also included are descriptions of seven recharge projects.

Climate change is expected to modify the hydrological cycle and affect freshwater resources. Groundwater is a critical source of fresh drinking water for almost half of the worlds population and it also supplies irrigated agriculture. Groundwater is also important in sustaining streams, lakes, wetlands, and associated ecosystems. But despite this,

Because water in the United State has not been traded in markets, there is no meaningful estimate of what it would cost if it were traded. But failing to establish ground water's valueâ€"for in situ uses such as sustaining wetlands as well as for extractive uses such as agricultureâ€"will lead to continued overuse and degradation of the nation's aquifers. In Valuing Ground Water an interdisciplinary committee integrates the latest economic, legal, and physical knowledge about ground water and methods for valuing this resource, making it comprehensible to decision-makers involved in Superfund cleanup efforts, local wellhead protection programs, water allocation, and other water-related management issues. Using the concept of total economic value, this volume provides a framework for calculating the economic value of ground water and evaluating tradeoffs between competing uses of it. Included are seven case studies where ground-water valuation has been or could be used in decisionmaking. The committee examines trends in ground-water management, factors that contribute to its value, and issues surrounding ground-water allocation and legal rights to its use. The book discusses economic valuation of natural resources and reviews several valuation methods. Presenting conclusions, recommendations, and research priorities, Valuing Ground Water will be of interest to those concerned about ground-water issues: policymakers, regulators, economists, attorneys, researchers, resource managers, and environmental advocates.