The appearance of this Second Edition has been encouraged by the favorable reception of the first. This has offered us the opportunity to update the materials and to expand the exposition ofour central theses concerning (1) the integration of water quantity-quality issues and the treatment of water as a multi-product commodity, with the market playing a major role in determining water quality-discriminant pricing; (2) the drawbacks of public controls, regulation and enforcement, and the need to expand privatization of water supply and of water and wastewater treatment facilities to ensure their appropriate development and modernization through increased reliance on private capital; (3) the unification and centralization of water management on the river basin level in order to handle effectively the expanding pressures for water availability, for the elimination of waterborne disease, for extensive and effective pollution abatement as well as coping with the related issues of soil erosion, siltation in streams, channels, and reservoirs, protection against distress from drought and floods, and with the myriad problems relating to the environment, recreation, and navigation. We have maintained the division ofthe book into four major parts and 12 chapters.

A special workshop on scale problems in hydrology was held at Princeton University, Princeton, New Jersey, during October 31-November 3, 1984. This workshop was the second in a series on this general topic. The proceedings of the first workshop, held in Caracas, Venezuela, in January 1982, appeared in the Journal of Hydrology (Volume 65:1/3, 1983). This book contains the papers presented at the second workshop. The scale problems in hydrology and other geophysical sciences stem from the recognition that the mathematical relationships describing a physical phenomenon are mostly scale dependent in the sense that different relationships manifest at different space-time scales. The broad scientific problem then is to identify and for mulate suitable relationships at the scales of practical interest, test them experimen tally and seek consistent analytical connections between these relationships and those known at other scales. For example, the current hydrologic theories of evaporation, infiltration, subsurface water transport and water sediment transport overland and in channels etc. derive mostly from laboratory experiments and therefore generally apply at "small" space-time scales. A rigorous extrapolation of these theories to large spatial and temporal basin scales, as mandated by practical considerations, appears very difficult. Consequently, analytical formulations of suitable hydrologic theories at basin wide space-time scales and their experimental verification is currently being perceived to be an exciting and challenging area of scientific research in hydrology. In order to successfully meet these challenges in the future, this series of workshops was initiated."

About four years ago Dr. Gilbert White visited China and sowed the seeds of this project through conversations with Drs. Huang and Gong of the Chinese Academy of Sciences, and Mr. Long of the Yellow River Conservancy Commission. After some additional rounds of communications by letter, the plan for a workshop evolved and Drs. Wolman and Brush visited with Dr. Sabadell of the Nat_ional Science Foundation to begin the initial planning. In March 1987 Dr. Brush visited China and the details were worked out for the October 1987 workshop. At the outset it was recognized that the 10 American scientists and engineers ltad very Ii ttle knowledge of the Yellow River and none had ever seen it. Therefore, it became important that field trips be scheduled before the workshop to better set the stage for fruitful discussions. It was also acknowledged that the American participants could not present papers about the Yellow River per se so their offerings reflected their general knowledge of rivers using other rivers as examples. On the other hand the Chinese participants were all well into the difficult problems of harnessing the Yellow River and made their presentations accordingly. Despite these differences the subject matter was the unifying thread and cross communication was excellent.

Floods constitute a persistent and serious problem throughout the United States and many other parts of the world. They are responsible for losses amounting to billions of dollars and scores of deaths annually. Virtually all parts of the nation--coastal, moun tainous and rural--are affected by them. Two aspects of the problem of flooding that have long been topics of scientific inquiry are flood frequency and risk analyses. Many new, even improved, tech niques have recently been developed for performing these analyses. Nevertheless, actual experience points out that the frequency of say a 100-year flood, in lieu of being encountered on the average once in one hundred years, may be as little as once in 25 years. It is therefore appropriate to pause and ask where we are, where we are going and where we ought to be going with regard to the technology of flood frequency and risk analyses. One way to address these ques tions is to provide a forum where people from all quarters of the world can assemble, discuss and share their experience and expertise pertaining to flood frequency and risk analyses. This is what con stituted the motivation for organizing the International Symposium on Flood Frequency and Risk Analyses held May 14-17, 1986, at Louisiana State University, Baton Rouge, Louisiana."

This book focuses on sediments as a pollutant in natural freshwater and marine habitats, and as a vector for the transfer of chemicals such as nutrients and contaminants. Sediment-water research is carried out all over the world within a variety of disciplines. The selected papers cover three main topics relating to assessment and/or restoration of disturbed watersheds, sediment-water linkages in terrestrial and aquatic environments and evaluation of sediment and ecological changes in marine and freshwater habitats. Innovative research in both developed and less developed countries is included. Both fundamental research, insight into applied research and system management are covered. The volume will also appeal to readers involved in sediment geochemistry and dynamics, aquatic habitats, water quality, aquatic ecology, river morphology, restoration techniques and catchment management.

This volume combines articles on shallow lakes from leading European scientists in limnology. It covers aspects of the dynamics of macrophytes, phytoplankton, zooplankton and benthos, nutrient loading, littoral-pelagic interactions, and sediment-water interactions, as well as lake management. The object was not to separate theory (e.g. modelling) and management in order to generate new theories for the understanding of shallow lake ecosystems. The volume provides a comprehensive overview of the ecology of shallow lakes, a lake type which differs in prominent ways from deeper lakes. The broad spectrum of issues may also reflect the spectrum of interested readers such as limnologists, water engineers, hydrobiologists, who will be informed on a high level about new developments.

This proceedings volume includes selected papers presented at the international symposium Live Food Organisms in Marine Larviculture' held in Nagasaki, Japan, September 1-4 1996. This international symposium focused on live food organisms for the larval rearing of marine animals. Recent achievements in the fundamental biology (such as physiology, ecology, taxonomy, life cycle and nutrition) of live planktonic animals used as feed in aquaculture were combined with recent technological advances on larval rearing methods. This volume also provides future directions for the application of basic science to the rearing of aquatic animals.

These proceedings of a workshop of the International Association for Phytoplankton Taxonomy and Ecology are directed specifically at the relationship between phytoplankton ecology and the trophic status of water bodies. Contributions address the fact that distinctive assemblages of phytoplankton species are closely associated with particular categories of water bodies. Particular attention is paid to how communities are assembled and to the ways in which environmental constraints filter the successful species. Overview articles are included. The book will be a valuable source of information to limnologists, algologists, and the technical staff of all water suppliers.

This book contains selected papers presented at the NATO Advanced Study Institute on "Strong Ground Motion Seismology," held in Ankara, Turkey between June 10 and 21, 1985. The strong ground motion resulting from a major earthquake determines the level of the seismic hazard to enable earthquake engineers to assess the structural performance and the consecutive risks to the property and life, as well as providing detailed information to seismologists about its source mechanism. From the earthquake engineering point the main problem is the specification of a design level ground motion for a given source-site-structure-economic life and risk combination through deterministic and probabilistic approaches. In seismology the strong motion data provide the high frequency information to determine the rupture process and the complexity of the source mechanism. The effects of the propagation path on the strong ground motion is a research area receiving sub stantial attenuation both from earthquake engineers and seismologists. The Institute provided a venue for the treatment of the subject matter by a series of lectures on earthquake source models and near field theories; effects of propagation paths and site conditions, numerical and empirical methods for prediction; data acquisition and analysis; hazard assessment and engineering application."

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.

This book tells a story of a large lake affected by agricultural and urban activities that have led to severe eutrophication problems with nuisance blue-green algal blooms. Although it is a case study of Lake Ringsjoen (southern Sweden), the background, problems and measures are applicable to many lakes throughout the world. From a limnological point of view, the Lake Ringsjoen story began more than 100 years ago, and during the last 20 years the sampling program has been intense, providing a unique data set on how a lake responds to human activities. However, the Lake Ringsjoen story is not only a case study, but also a historical record of the development of ecological theory and its application. Hence, the lake has been subject both to an extensive nutrient reduction programme and a biomanipulation by means of fish reduction. Here we aim at combining the unique limnological data set with the eutrophication process, the nutrient reduction programme and the biomanipulation in order to apply our empirical knowledge to future lake management measures.

In recent years, the adequacy of collected water quality data and the performance of existing monitoring networks have been seriously evaluated for two basic reasons. First, an efficient information system is required to satisfy the needs of water quality management plans and to aid in the decision-making process. Second, this system has to be realized under the constraints of limited financial resources, sampling and analysis facilities, and manpower. Problems observed in available data and shortcomings of current networks have led researchers to focus more critically on the design procedures used. The book is intended to present an up-to-date overview of the current network design procedures and develop basic guidelines to be followed in both the design and the redesign of water quality monitoring networks. The book treats the network design problem in a comprehensive and systematic framework, starting with objectives of monitoring and elaborating on various technical design features, e.g. selection of sampling sites, sampling frequencies, variables to be monitored, and sampling duration. The design procedures presented are those that the authors have recently applied in a number of national and international projects on the design and redesign of water quality monitoring networks. Thus, the book covers real case studies where not only the methods described in the earlier titles are used but also new techniques are introduced. Where earlier methods are used, they are assessed with respect to their efficiency and applicability to real case problems. Audience: Essentially, the framework adopted in the book applies as well to other hydrometric data collection networks besides those of water quality. In this respect, it is expected that planners, designers, scientists, and engineers who are involved in hydrometric network design will benefit from the in-depth approach assumed in this book. It will also be of interest to research and data centers, international programs and organizations related to environmental monitoring. The book may also be used as a reference text in graduate courses of water resources and environmental engineering programs.

This collection of articles provides a unique overview of the state of the science in the prediction of and response to natural disaster events. The uniqueness of this volume is that it comprises more than just the physical science perspective. For each natural hazard included in this text, social scientists have provided research summaries of how public perceptions are related to the actions that are likely to be undertaken when people are confronted with information about the existence of a natural hazard threat. In this book the reader can find a truly international characterization of both hazard perception and prediction. The American and European contributors provide state-of-the-science overviews of empirically-based research knowledge that expands beyond any national boundaries. This approach has resulted in broader understanding of what is currently known about predicting natural hazard events and predicting how those events, or warnings of them, will be responded to by different types of societies.

The General Assembly of the United Nations passed a resolution on December 11, 1987, designating the 1990s as the International Decade for Natural Disaster Reduction. This resolution has served as a catalyst in promotion of international cooperation in the field of natural disaster reduction; in initiation of wide-ranging research activities on natural and man-made disasters; in development of tech nologies for assessment, prediction, prevention, and mitigation through technical assistance, technology transfer, demonstration projects, and education and training; and in dissemination of information related to measures for assessment, prediction, prevention, and mitigation of natural disasters. Disasters are manifestations of environmental extremes. Depending upon the type of disasters, their occurrence may have short-term andlor long-term detri mental environmental consequences. Disasters cannot be prevented altogether, but their impact can be mitigated. This book is an attempt to provide a discussion of hydrological aspects of the various types of natural disasters. It is hoped that others will be stimulated to write more comprehensive texts on this subject of enormous importance."

Flood Problem and Management in South Asia focuses on both the hazard and the vulnerability aspects of floods. This book addresses floods in South Asia from a multidisciplinary approach. The characteristics and nature of the flood problem and its management aspects are examined. It is suggested that flood control and management focused on structural solutions using embankments and reservoirs are insufficient. Effective solutions must go beyond structural measures and require major restructuring of both legal systems and institutions responsible for management. For those people living in the vast flood plains of South Asia to be able to overcome social, economic and environmental vulnerabilities, an adaptive approach to management of flood risks that identifies specific strategies is needed.

Dams are constructed for economic development, and their construction involves large investments of money, and natural and human resources. Of the various types of dams constructed around the globe, earth dams are the most common type and constitute the vast majority of dams. When adam fails, it culminates in the sudden release of artificially stored water which, in turn, becomes a potential menace to virtually everything downstream. The dam failure may result in loss of life and property. In recent years, instances of dam failure in the world have been too many, and the resulting loss too high. As a result, dam safety pro grams have been developed in most countries of the world since the beginning of the nineteenth eighties. . Earth dams are more susceptible to failure than other types. The cause of failure is often either overtopping or piping. The modeling of dam breaching due to either or both of these causes is of fundamental importance to development of dam-safety programs. This book is, therefore, an attempt to present some aspects of earth-dam breach modeling technology. It is hoped that others will be stimulated to write more comprehensive texts on this subject of growing interest and importance. The book is divided into eight chapters. The first chapter is introductory and discusses some aspects of dams and dam failures in the world."

Computational Subsurface Hydrology: Fluid Flows offers practicing engineers and scientists a theoretical background, numerical methods, and computer codes for the modeling of fluid flows in subsurface media. It will also serve as a text for senior and graduate courses on fluid flows in subsurface media in disciplines such as civil and environmental engineering, agricultural engineering, geosciences, soil sciences, and chemical engineering. Computational Subsurface Hydrology: Fluid Flows presents a systematic derivation of governing equations and boundary conditions of subsurface fluid flow. It discusses a variety of numerical methods, expounds detailed procedures for constructing finite element methods, and describes precise implementation of computer codes as they are applied to subsurface flows. Four computer codes to simulate vertically integrated horizontal flows (FEWA), saturated flows with moving phreatic surfaces in three dimensions (3DFEWA), variably saturated flows in two dimensions (FEMWATER), and variable flows in three dimensions (3DFEMWATER) are attached to this book. These four computer codes are designed for generic applications to both research and practical problems. They could be used to simulate most of the practical, real-world field problems. If you would like a copy of the diskettes containing the four, basic general purpose computer codes referred to in Computational Subsurface Hydrology: Fluid Flows, please email Gour-Tsyh Yeh at the following address : [email protected]

The theory of the scattering of light by small particles is very important in a wide range of applications in atmospheric physics and atmospheric optics, ocean optics, remote sensing, astronomy and astrophysics and biological optics. This book summarises current knowledge of the optical properties of single small particles and natural light scattering media such as snow, clouds, foam aerosols etc. The book considers both single and multiple light scattering regimes, together with light scattering and radiative transfer in close-packed media. The third edition incorporates new findings in the area of light scattering media optics in an updated version of the text.

About 20 years ago the emphasis in soil chemistry research switched from studies of problems related to scarcities of plant nutrients to those arising from soil pollutants. The new problems have come about because of the excessive uses of fertilizers, the inputs from farm and industrial wastes, the widespread applications of anthropogenie xenobiotic chemicals, and the deterioration of soil structure resulting from certain modern agriculture practises. The International Society of Soil Science (ISSS) recognized these problems and challenges. A provisional Working Group was set up in 1978 to focus attention on soil colloids with a view to understanding better the interactions wh ich take place at their surfaces. It was recognized that these interactions are fundamental to problems of soil fertility, as weIl as to those of soil pollution. After the group had received the official support of ISSS at its 12th International Congress in New Delhi in 1982 it set as its priority the assembling and evaluation of information, relevant to the soil and environmental sciences, concerning the composition and structure of soil colloids. Prior to that aseries of Position Papers were published in the Bulletin of the International Society of Soil Science (Vol. 61, 1981) outlining the state of knowledge about the composition and properties of soil colloids.

Porous media, and especially phenomena of transport in such materials, are an impor1ant field of interest for geologists, hydrogeologists, researchers in soil and fluid mechanics, petroleum and chemical engineers, physicists and scientists in many other disciplines. The development of better numerical simulation techniques in combination with the enormous expansion of computer tools, have enabled numerical simulation of transport phenomena (mass of phases and components, energy etc. ) in porous domains of interest. Before any practical application of the results of such simulations can be used, it is essential that the simulation models have been proven to be valid. In order to establish the greatest possible coherence between the models and the physical reality, frequent interaction between numericians, mathematicians and the previously quoted researchers, is necessary. Once this coherence is established, the numerical simulations could be used to predict various phenomena such as water management, propagation of pollutants etc. These simulations could be, in many cases, the only financially acceptable tool to carry out an investigation. Current studies within various fields of applications include not only physical comprehension aspects of flow and energy or solute transport in saturated or unsaturated media but also numerical aspects in deriving strong complex equations. Among the various fields of applications generally two types of problems can be observed. Those associated with the pollution of the environment and those linked to water management. The former are essentially a problem in industrialized countries, the latter are a major source of concern in North-Africa.

The first Symposium on Recent Advances in Problems of Flow and Transport in Porous Media was held in Marrakech in June '96 and has provided a focus for the utilization of computer methods for solving the many complex problems encountered in the field of solute transport in porous media. This symposium has been successful in bringing together scientists, physicists, hydrogeologists, researchers in soil and fluid mechanics and engineers involved in this multidisciplinary subject. It is clear that the utilization of computer-based models in this domain is still rapidly expanding and that new and novel solutions are being developed. The contributed papers which form this book reflect the recent advances, in particular with respect to new methods, inverse problems, reactive transport, unsaturated media and upscaling. These have been subdivided into the following sections: I. Numerical methods II. Mass transport and heat transfer III. Comparison with experimentation and simulation of real cases This book contains reviewed articles of the top presentations held during the International Symposium on Computer Methods in Porous Media Engineering which took place in Giens (France) in October 1998. All of the presentations and the optimism shown during the meeting provided further evidence that computer modeling is making remarkable progress and is indeed becoming an essential toolkit in the field of porous media and solute transport. I believe that the content of this book provides evidence of this and furthermore gives a comprehensive review of the theoretical developments and applications.

The diverse nature of environmental problems mankind has encountered within the last decade has developed a new understanding of the nature of environmental processes. Currently, the environment is considered as a continuum of air, soil and water as the vital components for sustaining life on earth. The interactive nature of these components requires that the environment is managed and protected as a cohesive whole. This can only be accomplished through an integrated approach to environmental management. Besides the concept of environmental continuum, prospects for sustainable development of natural resources and the recent recognition of global climate change impacts have also necessitated such an integrated approach to environmental management. Two basic tools for integrated management of the environment are modeling and environmental data. Both tools were available and valid in the past; however, the recent requirements for integrated environmental management have also led to a significant evolution of both modeling procedures and data management systems.

Desertification has occurred worldwide. The biophysical and socio-economic complexity of this phenomenon has challenged our ability to categorize, inventory, monitor and repair the condition of degraded lands. One of the most important distinctions to be made in relation to land degradation is between cultivated land used for annual crop production and rangelands'. Grazing by free-roaming livestock is the traditional primary use of the world's rangelands. However, there is growing recognition of the importance of these vast acreages for wildlife habitat, hydrology and ground water recharge, recreation and aesthetics. This text focuses on the desertification of rangelands and explores processes, problems and solutions. Chapters in the first section evaluate interactions between natural' and human-induced disturbance regimes, thresholds, and non-linear change with respect to vegetation, hydrology, nutrients and erosion. Chapters in the second section examine socio-economic constraints and approaches for preventing and reversing degradation. The book provides a contemporary, process-oriented perspective on rangeland degradation of value to students, policy-makers and professionals alike.

Greenhouse-induced climate warming increasingly appears to be a reality, and the warming climate will be accompanied by an accelerated sea level rise - as much as 60-100 cm over the next century. What is commonly absent in the discussion of rising sea level, however, is the role played by the subsidence of low-lying coastal areas, which can have a far greater local effect than the eustatic rise of the sea. The combined sea-level rise and land subsidence will almost certainly make the greatest impact on coastal societies in the densely populated regions of southern Asia, but its effects will be felt globally. This volume explores the concepts of sea-level rise and coastal subsidence, both natural and anthropogenically accelerated, in the form of a series of case studies in such diverse locations as Bangkok, Bangladesh, Venice, and the Niger and Mississippi deltas, as well as a discussion of the economic, engineering and policy responses that must be considered if the effects of local sea-level rise are to be mitigated.

Recent years have witnessed the development of computational geomechanics as an important branch of engineering. The use of modern computational techniques makes it possible to deal with many complex engineering problems, taking into account many of the typical properties of geotechnical materials (soil and rock), such as the coupled behaviour of pore water and solid material, nonlinear elasto-plastic behaviour, and transport processes. This book provides an introduction to these methods, presenting the basic principles of the geotechnical phenomena involved as well as the numerical models for their analysis, and including full listings of computer programs (in PASCAL). The types of geotechnical problems considered cover a wide range of applications, varying from classical problems such as slope stability, analysis of foundation piles and sheet pile walls to finite element analysis of groundwater flow, elasto-plastic deformations, consolidation and transport problems.