Volume 1: (edited by Keith W. Hipel) In this landmark collection of papers, highly respected scientists and engineers from around the world present the latest research results in extreme value analyses for floods and droughts. Two approaches that are commonly employed in flood frequency analyses are the maximum annual flood and partial duration series or peak over threshold procedures. Recent theoretical advances as well as illustrative applications are described in detail for each of these approaches. Additionally, droughts and storms are systematically studied using appropriate probabilistic models. A major part of the volume is devoted to frequency analyses and fitting extreme value distributions to hydrological data. Other thought-provoking topics include regionalization techniques, distributed models, entropy and fractal analysis. Volume 1 is of interest to researchers, teachers, students and practitioners who wish to place themselves at the leading edge of flood frequency and drought analyses. Volume 2: (edited by Keith W. Hipel) World renowned scientists present valuable contributions to stochastic and statistical modelling of groundwater and surface water systems. The philosophy of probabilistic modelling in the hydrological sciences is put into proper perspective and the importance of stochastic differential equations in the environmental sciences is explained and illustrated. The new research ideas put forward in groundwater modelling will assist decision makers in tackling challenging problems such as controlling pollution of underground aquifers and obtaining adequate water supplies. Additionally, different types of stochastic models are used in modelling a range of interesting surface water problems. Other topics covered in this landmark volume include stochastic optimization, moment analysis, carbon dioxide modelling and rainfall prediction. Volume 2 is of interest to researchers, teachers, students and practitioners who wish to be at the leading edge of stochastic and statistical modelling in the environmental sciences. Volume 3: (edited by Keith W. Hipel; A. Ian McLeod; U.S. Panu; Vijay P. Singh) International experts from around the globe present a rich variety of intriguing developments in time series analysis in hydrology and environmental engineering. Climatic change is of great concern to everyone and significant contributions to this challenging research topic are put forward by internationally renowned authors. A range of interesting applications in hydrological forecasting are given for case studies in reservoir operation in North America, Asia and South America. Additionally, progress in entropy research is described and entropy concepts are applied to various water resource systems problems. Neural networks are employed for forecasting runoff and water demand. Moreover, graphical, nonparametric and parametric trend analyses methods are compared and applied to water quality time series. Other topics covered in this landmark volume include spatial analyses, spectral analyses and different methods for stream-flow modelling. Volume 3 constitutes an invaluable resource for researchers, teachers, students and practitioners who wish to be at the forefront of time series analysis in the environmental sciences. Volume 4: (edited by Keith W. Hipel; Liping Fang) In this landmark set of papers, experts from around the world present the latest and most promising approaches to both the theory and practice of effective environmental management. To achieve sustainable development, organizations and individual citizens must comply with environmental laws and regulations. Accordingly, a major contribution of this book is the presentation of original techniques for designing effective environmental policies, regulations, inspection procedures and monitoring systems. Interesting methods for modelling risk and decision making problems are discussed from an environmental management perspective. Moreover, knowledge-based techniques for handling environmental problems are also investigated. Finally, the last main part of the book describes optimal approaches to reservoir operation and control that take into account appropriate multiple objectives. Volume 4 is of direct interest to researchers, teachers, students and practitioners concerned with the latest developments in environmental management and sustainable development.

This volume certainly is a Conference Proceedings, the Proceedings of the NATO Advanced Research Workshop (ARW) on "Unsaturated Flow in Hydrologic Modeling" held at "Les Villages du Soleil" near ArIes, France from June 13 to 17, 1988. Let me therefore acknowledge properly, at the very beginning, the gratitude of all the participants to the NATO Science Committee for its generous support and worthwhile goal of bringing together scientists of many countries to communicate and share their experiences. Particular thanks are extended to the director of the program, Dr. Luis Vega da Cunha for his interest and understanding. On the other hand this volume is also, and probably more so, a Textbook that fills a gap in the field of unsaturated flow. Many treatises on the subject present the theory in its different aspects. Hardly any explain in details how the different pieces can be put together to address realistic problems at the basin scale. The various invited contributions to the ARW were structured in a subject progression much as chapters are organized in a book. The intent of the ARW was to assess the current state of knowledge in "Unsaturated Flow" and its use in "Hydrologic Modeling Practice." In a sense the interest in fundamentals of unsaturated flow in this ARW was not just for the sake of knowledge but also and primarily for the sake of action. Can such fundamental knowledge be utilized for better management of the water resource? was the basic question.

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."

The Brahmaputra River represents nearly 30% of India's water resources potential and 41% of its total hydropower. No sustainable future for this underdeveloped region can occur without a plan combining social, political, economic, cultural, and legal considerations with scientific paradigms. This book pools the talent, knowledge and experience of a wide range of water resource professionals to provide an exhaustive study of the Brahmaputra River basin, present and future.

Exploring Risk Communication presents a systematic planning approach to risk communication. Risk communication is seen by many as an important tool for managing technological, environmental, and natural risks. The book's goal is to improve risk communication processes in these areas between private and public risk communication sources and the public. The systematic planning approach focuses on research activities which are considered to be diagnostic tools providing insight into the public's reactions to risks and into the public's cognitive abilities to process risk information. These studies give us the necessary ingredients for an adequate risk communication from the audience side of the risk communication process. Evaluation studies are considered necessary to monitor the effectiveness of the communication. Exploring Risk Communication provides a review of current research in risk communication, focusing on perceived trust and credibility of risk communication sources, and arguments in risk messages, risk comparison, and framing of risk. Special attention is paid to the mass media context of risks and its impact on public perception. Finally, the potential of the new interactive media for risk communication is reviewed. The authors have performed several communication studies in the risk area, working from their social psychological background. This results in a monograph interesting to those working on risk communication issues on an academic level, but the systematic planning approach is also a useful frame of reference for risk communication practitioners, or for those who are just interested in the often complex risk communication issues.

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 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.

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.

... A diskette with the updated programme of Appendix C and examples is available through the author at a small fee.
email: [email protected]
fax: 1--310--825--5435 ...
This book systematically discusses basic concepts, theory, solution methods and applications of inverse problems in groundwater modeling. It is the first book devoted to this subject.
The inverse problem is defined and solved in both deterministic and statistic frameworks. Various direct and indirect methods are discussed and compared. As a useful tool, the adjoint state method and its applications are given in detail. For a stochastic field, the maximum likelihood estimation and co-kriging techniques are used to estimate unknown parameters. The ill-posed problem of inverse solution is highlighted through the whole book. The importance of data collection strategy is specially emphasized. Besides the classical design criteria, the relationships between decision making, prediction, parameter identification and experimental design are considered from the point of view of extended identifiabilities. The problem of model structure identification is also considered.
This book can be used as a textbook for graduate students majoring in hydrogeology or related subjects. It is also a reference book for hydrogeologists, petroleum engineers, environmental engineers, mining engineers and applied mathematicians.

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.

Since the pioneering work of Shannon in the late 1940's on the development of the theory of entropy and the landmark contributions of Jaynes a decade later leading to the development of the principle of maximum entropy (POME), the concept of entropy has been increasingly applied in a wide spectrum of areas, including chemistry, electronics and communications engineering, data acquisition and storage and retreival, data monitoring network design, ecology, economics, environmental engineering, earth sciences, fluid mechanics, genetics, geology, geomorphology, geophysics, geotechnical engineering, hydraulics, hydrology, image processing, management sciences, operations research, pattern recognition and identification, photogrammetry, psychology, physics and quantum mechanics, reliability analysis, reservoir engineering, statistical mechanics, thermodynamics, topology, transportation engineering, turbulence modeling, and so on. New areas finding application of entropy have since continued to unfold. The entropy concept is indeed versatile and its applicability widespread. In the area of hydrology and water resources, a range of applications of entropy have been reported during the past three decades or so. This book focuses on parameter estimation using entropy for a number of distributions frequently used in hydrology. In the entropy-based parameter estimation the distribution parameters are expressed in terms of the given information, called constraints. Thus, the method lends itself to a physical interpretation of the parameters. Because the information to be specified usually constitutes sufficient statistics for the distribution under consideration, the entropy method provides a quantitative way to express the information contained in the distribution.

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.

The last few years have witnessed an enormous interest in application of GIS in hydrology and water resources. This is partly evidenced by organization of sev eral national and international symposia or conferences under the sponsorship of various professional organizations. This increased interest is, in a large measure, in response to growing public sensitivity to environmental quality and management. The GIS technology has the ability to capture, store, manipulate, analyze, and visualize the diverse sets of geo-referenced data. On the other hand, hydrology is inherently spatial and distributed hydrologic models have large data requirements. The integration of hydrology and GIS is therefore quite natural. The integration involves three major components: (1) spatial data construction, (2) integration of spatial model layers, and (3) GIS and model interface. GIS can assist in design, calibration, modification and comparison of models. This integration is spreading worldwide and is expected to accelerate in the foreseeable future. Substantial op portunities exist in integration of GIS and hydrology. We believe there are enough challenges in use of GIS for conceptualizing and modeling complex hydrologic processes and for globalization of hydrology. The motivation for this book grew out of the desire to provide under one cover a range of applications of GIS tech nology in hydrology. It is hoped that the book will stimulate others to write more comprehensive texts on this subject of growing importance."

It is an honour and pleasure to write a foreword to this useful and interesting book. Authors are very well known researchers who pioneered percolation modelling of transport in porous media in Russia from the early 80-th till nowadays. The main scope of the work presented in the book was developed when bright papers by A. Aharony, H.T. Davis, F.A.L. Dullien, A.A. Heiba, R.G. Larson, R. Lenormand, M.Sahimi, L.E. Scriven, D. Stauffer, M. Yanuka, Y.C.Yortsos were not available at the "other" side of the Iron Curtain. Nowadays hundreds of works and papers with the "percolation" keywords ap pear in petroleum and related applied research areas. The book will take a re markable place in the "petroleum percolation" bibliography. There are two important features of novelty in the monograph presented. First of all the authors developed a generalization of percolation clusters theory for grids with varying conductivity. Technique of representation of an infinite cluster as an hierarchial set of trees (so called r-chain model) allows to present conductivity of a stochastic grid in a closed form of explicit formulae. This method differs from those known in the West, such as effective media theory, solutions for the Bethe-lattice, etc. It has his own area of successful appli cations."

There are few books and long review articles on water reservoir induced seismicity, mining induced seismicity and even on volcanic seismicity but the subjects of induced seismicity following fluid extraction and nuclear explosion and seismicity associated with tidal stress in Earth have not received significant attention though there are research papers in relevant literature. Thus an attempt has been made to discuss all the known forms of induced seismicity in the present book and to bring out common features of the different phenomena causing induced seismicity. The book has six main chapters namely 2, 3, 4, 5, 6 and 7, the first and last chapters, namely 1 and 8 being introduction and overview of all forms of induced seismicity. Material in Chapters 2 and 3 is rather recent though water reservoirs and petroleum extraction processes have been in existence over many decades. But, literature on chapters 4 and 5 is available since last one century or so as volcanic process and mining operation affect nearby human habitation and mining severely due to induced seismicity associated with mining in particular. However, literature on possible induced seismicity due to tidal stress is fairly old, the same following nuclear explosion is naturally recent.

Since the dissolution of the Soviet Union almost a decade ago, there has been rapid evolution of interactions between the Western nations and individual countries of the former Soviet Union. As part of that interaction, the autonomous independent Republic of Azerbaijan through its scientific arm, the Geological Institute of the Azerbaijan Academy of Sciences under the Directorship of Academician Akif Ali-Zadeh and Deputy Director Ibrahim Guliev, arranged for personnel to be seconded to the University of South Carolina. The idea here was to see to what extent a quantitative understanding could be achieved of the evolution of the Azerbaijan part of the South Caspian Basin from dynamical, thermal and hydrocarbon perspectives. The Azeris brought with them copious amounts of data collected over decades which, together with the quantitative numerical codes available at USC, enabled a concerted effort to be put forward, culminating in two large books (Evolution of the South Caspian Basin: Geological Risks and Probable Hazards, 675 pps; and The South Caspian Basin: Stratigraphy, Geochemistry, and Risk Analysis, of which were published by the Azerbaijan Academy of 472 pps. ) both Sciences, and also many scientific papers. Thus, over the last four to five years an integrated comprehensive start has been made to understand the hydrocarbon proneness of the South Caspian Basin. In the course of the endeavor to understand the basinal evolution, it became clear that a variety of natural hazards occur in the Basin.

A multidecadal cooling is known to have occurred in Europe in the final decades of the sixteenth-century. It is still open to debate as to what might have caused the underlying shifts in atmospheric circulation and how these changes affected societies. This book is the fruit of interdisciplinary cooperation among 37 scientists including climatologists, hydrologists, glaciologists, dendroclimatologists, and economic and cultural historians. The known documentary climatic evidence from six European countries is compared to results of tree-ring studies. Seasonal temperature and precipitation are estimated from this data and monthly mean surface pressure patterns in the European area are reconstructed for outstanding anomalies. Results are compared to fluctuations of Alpine glaciers and to changes in the frequency of severe floods and coastal storms. Moreover, the impact of climate change on grain prices and wine production is assessed. Finally, it is convincingly argued that witches at that time were burnt as scapegoats for climatic change.

Newly developed and innovative methods are mentioned and outlined so that the book can be used as a source of information for scientists and professionals specialised in the treatment of soils as well as for students in courses of environmental studies. The book offers a short, compressed overview of the important features of this subject and can be used as a reference book of the state of the art. The appendix offers the interested reader a detailed survey of materials, test methods and apparatuses as well as a description of analytical directions and processes.

"Climatic Change and Water Resources in the Middle East and North Africa" is dedicated to high-priority topics related to the impact of climate change on water resources in a water scarce region. The subject is described and discussed in three main chapters and different case studies. The three main chapters are (1) Climatic changes - sources and effects on the water cycle, (2) Impact of climate change on water resources, (3) Water resources and water management. These chapters are split up into further 26 sections. A total of 64 individuals from many countries have made contributions to this book. All topics in this book are complimentary and contribute to a comprehensive understanding of the interactions between global climate change, world water cycle and water resources. A valuable and meaningful interdisciplinary mixture of topics is combined in this book which will be of great interest to many scientists.

Groundwater constitutes the most important reservoir of available clean water. Due to its overexploitation, some anthropogenic mismanagement on the surface and the overloading of the cleanup potential of subsurface, many of the groundwater systems used for water supply are in jeopardy. The problem is very severe in dry-lands, but also in urban, industrial, agricultural and traffic areas.

This book first addresses the recharge fluxes relating both to the quantity and quality of groundwater. In order to face the threats to the water supply and to be able to maintain a sustainable water management policy, detailed knowledge is needed on the surface-to-subsurface transformation link in the water cycle. Secondly, a comparison of both the traditional and modern approaches to determine groundwater recharge is presented. The traditional approach to determine groundwater recharge is based on water balance estimates and hydraulic considerations, which yield instantaneous values at best but do not integrate the totality of recharge pathways in time and space. In contrast, environmental tracers integrate these factors. Finally, the fate of groundwater recharge in the subsurface by hydraulic and geologic means is explained in detail, in order to stimulate adapted groundwater-management strategies and to better assess consequences of climate changes on groundwater resources as a whole.

Leonardo da Vinci, the eminent Renaissance scholar and philosopher said, "water is the driver of nature." Many may have considered it to be an overstatement in the past, but at the beginning of the third millennium, no sane individual would disagree with Leonardo's view. Water is becoming an increasingly scarce resource for most of the world's citizens. The current trends indicate that the overall situation is likely to deteriorate further, at least for the next two decades, unless the water profession eschews its existing "business as usual" practices, which can only allow incremental changes to occur. Somewhat surprisingly, the water profession as a whole neither realised nor appreciated the gravity of the global water situation as late as 1990, even though a few serious scholars have been pointing out the increasing criticality of the situation from around 1982. For example, the seriousness of the crisis was not a major issue, either at the International Conference on W ater and the Environment, which was organised by the UN system in Dublin and also at the UN Conference on Environment and Development at Rio de Janeiro. Held in 1992, both are considered to be important events for the water sector of the past decade. It is now being increasingly recognised that the Dublin Conference was poorly planned and organised, and thus not surprisingly it produced very little, if any, worthwhile and lasting results.

This book focuses on sustainable use and protection of transboundary aquifers located along the eastern border of European Union starting from the Baltic Sea and end in the Black Sea. The groundwater resources in this region play a very important role not only as a source of clean and safe drinking water, but also for social, economic and safety reasons. This publication sheds light on a wide range of real problems related to the management of groundwater, problems that are characteristic for most countries situated in the East European region. It also identifies potential threats that may materialise in the absence of cooperation between countries and appropriate measures to jointly manage the shared water resources in the region. Experience from some ongoing projects towards integrated management of transboundary aquifers (research, monitoring and data analysis) is reported. The book is addressed, in particular, to groundwater academics, researchers and experts as well as water management specialists interested in solving environmental issues extended to more than one country territory. On the other hand presented knowledge and experience would be also useful for decision makers especially to support environmental decision processes in border areas and work on preparation of international agreements on groundwater management.

stable or falling water levels, and permit differen tiation between gradual and sudden transgression The level of Lake Ontario was long assumed to of the shoreline. Vegetational succession reflects have risen at an exponentially decreasing rate shoreline transgression and increasing water solely in response to differential isostatic rebound depth as upland species are replaced by emergent of the St. Lawrence outlet since the Admiralty aquatic marsh species. If transgression continues, Phase (or Early Lake Ontario) 11 500 years B. P. these are in turn replaced by floating and sub (Muller & Prest, 1985). Recent work indicates merged aquatic species, commonly found in water that the Holocene water level history of Lake to 4 m depth in Ontario lakes, below which there Ontario is more complex than the simple rebound is a sharp decline in species richness and biomass model suggests. Sutton et al. (1972) and (Crowder et al., 1977). This depth varies with Anderson & Lewis (1982, 1985) indicate that physical limnological conditions in each basin. periods of accelerated water level rise followed by Because aquatic pollen and plant macrofossils are temporary stabilization occurred around 5000 to locally deposited, an abundance of emergent 4000 B. P. The accelerated water level rise, called aquatic fossils reflects sedimentation in the littoral the 'Nipissing Flood', was attributed to the cap zone, the part of the basin shallow enough to ture of Upper Great Lakes drainage. support rooted vegetation."