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Books > Earth & environment > Earth sciences > The hydrosphere > Hydrology (freshwater)
Egypt is a country of tremendous land resources but limited water resources The area of cultivated land is only 3.2% of the gross area. The river Nile is the main sources of water. In the recent years the Governement established large-scale agricultural projects in light of food security related to the population growth. Expansion of irrigated agriculture has to be predomantly relalized bt increasing the water use efficiency. In Egypt, the dominant irrigation method is surface irrigation, which covers approximately 83% of the irrigated areas. Surface irrigation or gravity methods are generally characterized by a low efficiency. One opportunity to increase the efficiency is to convert surface irrigation to modern irrigation systems, which are generaly highly expensive for a country like Egypt. Another option to increase the efficiency of surface irrigation systems is to convert the traditional irrigation method based on continuous flow to surge flow irrigation. Surge flow irrigation is the intermittent application of water to furrows in a series of relatively short on and off time periods. This study has been carried out to demonstrate the applicability of surge flow irrigation for water saving under the short field conditions that prevail in Egypt. The results indicate that surge flow irrigation is an effective irrigation method to save water and to increase crop production.
This wide-ranging selection of original papers covers many aspects of desertification including environmental and weather factors, land management policy, groundwater resources, understanding biodiversity in fragile ecosystems, technological approaches to the study and remedy of desertification.
Environmental politics has traditionally been a peripheral concern for international relations theory, but increasing alarm over global environmental challenges has elevated international society's relationship with the natural world into the theoretical limelight. IR theory's engagement with environmental politics, however, has largely focused on interstate cooperation in the late twentieth century, with less attention paid to how the eighteenth- and nineteenth-century quest to tame nature came to shape the modern international order. The ideal river examines nineteenth-century efforts to establish international commissions on three transboundary rivers - the Rhine, the Danube, and the Congo. It charts how the Enlightenment ambition to tame the natural world, and human nature itself, became an international standard for rational and civilized authority and informed our geographical imagination of the international. This relationship of domination over nature shaped three core IR concepts central to the emergence of early international order: the territorial sovereign state; imperial hierarchies; and international organizations. The book contributes to environmental politics and international relations by highlighting how the relationship between society and nature is not a peripheral concern, but one at the heart of international politics. -- .
Arid and semi-arid regions can be defined as environments in which water is the limit ing factor for bio-systems. This means that survival of life in these regions involves a constant struggle to obtain this limited commodity and draw the maximum benefit out of it. However, despite the difficulties for plants, animals, and man to live in, these regions, they are being utilized more and more because of the pressure of world population growth. This is expressed in the expansion of agricultural activities in desert lands as well as by the formation and rapid growth of urban and industrial centers. These trends result in a growing demand for water on the one hand, and the disposal of vast amounts of waste water, as well as other types of refuse, on the other. Meeting the first demand, namely, supplying water to the agricultural communities and urban centers, involves, in many instances, the over-exploitation and misuse of nat ural water resources. The surplus of waste water, sometimes highly loaded with toxic compounds, is likely to cause irreversible damage to the environment. The geoscientists and engineers face a challenge on two conflicting fronts. Success on one front, namely, in answering the full demand for water, may lead to an increase in the pollution of the environment by waste water."
A stand-alone working document, Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers assists scientists and regulators in determining when stormwater runoff causes adverse effects in receiving waters. This complicated task requires an integrated assessment approach that focuses on sampling before, during, and after storms. The Handbook supplies assessment strategies, sample testing and collection methods, and includes illustrative figures and tables.
An exploration of the relationship between river behaviour and environmental change. The research involves a wide range of disciplines including geomorphology, geophysics, archaeology, palaeoecology, engineering and planning.
Since human beings first appeared on the earth, we have changed land cover and land use for our own purposes, such as conveniences and high productivity. As a result of the land cover and land use changes, many serious environmental problems occur on the earth. Studying meteorological and hydrological effects of vegetation and land cover/use changes helps us to understand the environmental changes and problems happening near the earth surface, because the vegetation distributes the solar energy and water on the earth surface into atmosphere and geosphere. Subsurface hydrological responses to land cover and land use changes have drawn only regional environmental concerns, although global change caused by biosphere change has been studied in various scientific fields. The changes in land cover and land use alter water, solute and heat cycles in basins and elements of those balances, including evapotranspiration, groundwater recharge rate, discharge rates into rivers or ocean and soil moisture content, which are directly or indirectly related to the global environmental issues. Therefore, the changes in biosphere may substantially alter the subsurface hydrological system. For instance, increased groundwater recharge rates following clearing forest into grasses might be one consequence resulting in rising water tables and salinization.
The applications of stochastic methods in design by reliability include the better utilisation of hydrological information. With statistical methods one can evaluate the safety component of hydraulic systems. Based on these, extra safety features can be added to ensure the reliable performance of an hydraulic system. One such example is the design of a dam, which features a number of random variables, each with a very distinct and quite different probability function. This book reports on developments in stochastic hydraulics across a wide range of applications, including river hydraulics, sediment transportation, waves and coastal processes, hydrology, hydraulic works and structure, and environmental hydraulics.
Carbonate aquifers are an important source of water throughout the world. They are complicated systems and not always easy to interpret. Caves and channels form in the rock, leading to complex flow pathways and unpredictable contaminant behaviour. This volume covers the range of techniques used to analyse groundwater flow and contaminant transport in carbonate aquifers. The book opens with a review of thoughts and methods, and continues by discussing the use of tracers, hydrograph and hydrochemograph evaluation, estimation of aquifer properties from outcrop studies, numerical simulation, analogue simulation, and 3-D visualization of conduits. Other papers address the critical evaluation of matrix, fracture and conduit components of flow and storage. An understanding of these approaches is important to engineers or hydrogeologists working in carbonate aquifers.
Containing over one hundred and sixty line drawings, maps and one hundred tables, this book explains the fundamental hydrologic principles and favoured methods of analysis. Aimed at students interested in natural resources and environmental science, spreadsheet exercises and worked examples help to develop basic problem solving skills.
In aquatic ecosystems, the oligochaetes are often a major component of the community. Their relevance in sediment quality assessment is largely related to their benthic and detritivorous life habit. In this book, we aim to present the state of the art of Pollution Biology using oligochaete worms in laboratory and field studies. Future research will require the combination of a variety of methodological approaches and the integration of the resulting information, avoiding fragmented and often conflicting visions of the relationships of the species with their environment. Current approaches to ecotoxicology and bioaccumulation using ecological risk assessment provide the opportunity to relate community studies with probability of effects. This book addresses three main themes: Ecological and Field Studies using the composition and structure of oligochaete communities, Toxicology and Laboratory Studies, and Bioaccumulation and Trophic Transfer Studies. Two appendices list values of toxicological parameters (LC50, EC50) and several bioaccumulation variables (bioaccumulation factors, biological half-life, toxicokinetic coefficients, and critical body residues) for different oligochaete species. Additional information is provided on Methodological Issues and on the Taxonomy of several oligochaete families, with information on the most recent taxonomic debates. Each chapter includes a critical view, based on the authors experience, of a number of current issues which have been raised in the literature.
This text covers the proceedings of the third International Symposium - TISAR 98, held in Amsterdam. Topics include: basin recharge; water management in arid regions; behaviour of pollutants; bank, basin, well and other types of recharge; and storage and recovery efficiency.
One of the basic concepts of ocean biogeochemistry is that of an ocean with extremely active boundary zones and separation boundaries of extensive biochemical interactions. The areas of these zones are characterized by a sharp decrease of element migration intensity and consequently the decrease in their concentrations gave the boundaries for the naming of the geochemical barriers (Perelman, 1972). For the purposes of biogeo chemistry the most important ones are the boundaries of separation between river-sea, ocean-atmosphere, and water-ground (Lisitzin, 1983). The most complicated of them is the river-sea boundary, where the biogeochemical processes are the most active and complicated (Monin and Romankevich, 1979, 1984). The necessity of studying organic matter in rivers, mouth regions and adjoining sea aquatories has been repeatedly pointed out by v.I. Vernadsky (1934, 1960) who noted both the importance of registration of solid and liquid run-off of rivers, coming into the sea, and "the quality and the character of those elements, which are washed-down into the sea," emphasizing that "wash-down of organic substances into the sea is of great value." The interest in studying organic matter in natural waters, including river and sea waters, has grown considerably over the last 30 years. During this period essential material was collected on the content and composition of organic matter in various types of river waters of the USSR, and this was published in papers by B.A Scopintzev, AD. Semenov, M.V."
R. S. GOVINDARAJU and ARAMACHANDRA RAO School of Civil Engineering Purdue University West Lafayette, IN. , USA Background and Motivation The basic notion of artificial neural networks (ANNs), as we understand them today, was perhaps first formalized by McCulloch and Pitts (1943) in their model of an artificial neuron. Research in this field remained somewhat dormant in the early years, perhaps because of the limited capabilities of this method and because there was no clear indication of its potential uses. However, interest in this area picked up momentum in a dramatic fashion with the works of Hopfield (1982) and Rumelhart et al. (1986). Not only did these studies place artificial neural networks on a firmer mathematical footing, but also opened the dOOf to a host of potential applications for this computational tool. Consequently, neural network computing has progressed rapidly along all fronts: theoretical development of different learning algorithms, computing capabilities, and applications to diverse areas from neurophysiology to the stock market. . Initial studies on artificial neural networks were prompted by adesire to have computers mimic human learning. As a result, the jargon associated with the technical literature on this subject is replete with expressions such as excitation and inhibition of neurons, strength of synaptic connections, learning rates, training, and network experience. ANNs have also been referred to as neurocomputers by people who want to preserve this analogy.
Engineers from around the world recount in this volume their successes and failures in attempting to deal with unique and quixotic landscapes.
Borehole geophysics is frequently applied in hydrogeological environmental investigations where, for example, sites must be evaluated to determine the distribution of contaminants. It is a cost-effective method for obtaining information during several phases of such investigations.
This book gives an overall analysis of the current knowledge status about structures, functions, utilization for German Baltic coast ecosystems. The main focus of this book is on the aquatic area, but land/sea interactions as well as river outfalls are included as well. Characteristic for this book is the inclusion of social science aspects. Approximately one third of its extent will be about the ecosystem services. In this segment the results of the last 6 years are presented in which a comprehensive quantification of the social relevance of ecosystems was carried out covering the entire area of the German Baltic Sea. This part builds directly on the results of scientific investigations and are in relation to social ideals. The assessment will not only be economically and ethically but also the mechanisms that are used for the valorisation of the ecosystem services will be evaluated. Both sub-areas, the classic natural science part as well as the part of social science aspects, deal with the changes caused by increasing anthropogenic influence and social (including demographic) changes. This will be among others in the sense of an exemplary historical outline. The final chapter of the synthesis therefore not only presents a summary of the level of knowledge gained and a deduction of the research needs. It further contains a presentation of the application aspects resulting from the analysis of the social relevance gained from basic scientific research. The book is aimed at scientists (and students) of natural, life and social sciences, analysing functioning and structures of coastal ecosystems with regard to sustainable use and nature protection, including aspects of coastal protection. Besides, it is thought to become a reference for all levels of decision makers and stakeholders in coastal and marine management of the Baltic and North Sea region, providing also a blueprint for system analysis respecting for societal as well as biological aspects world-wide.
Many areas of the world are arid or semi-arid. This text looks at the problems caused by the loss of water stored in lakes and reservoirs for irrigation and domestic use by evaporation during the summer months.
Vadose Zone Hydrology describes the elements of the physical
processes most often encountered by hydrogeologists and
ground-water engineers in their vadose zone projects. It
illustrates the application of soil physics to practical problems
relevant to the characterization and monitoring of the vadose zone.
It includes an introduction to physical processes, including basic
flow theory, and provides examples of important field-scale
processes that must be recognizable by hydrogeologists.
Considerable attention is given to the concepts of recharge,
including how it is most accurately evaluated in the vadose zone.
Field and laboratory methods for characterizing hydraulic
properties in the vadose zone are also covered, and case studies
illustrating these methods are provided. New and emerging
technologies for monitoring the vadose zone, particularly for the
purpose of detecting contaminants, are highlighted. In the last
section of the book, additional case studies are presented,
demonstrating applications related to seepage detection, landfill
monitoring, and soil gas investigations.
This book explains clearly how and where groundwater occurs, how it is used and how it is at risk.
Humic Substances color all waters more or less brown. Their concentrations exceed all carbon of living organisms by at least one order of magnitude. Opposite to former paradigms, they participate in almost any metabolic pathway. They protect against UV-irradation, enable indirect photolysis and, thus, purify hazardous chemicals, they provide inorganic and organic nutrients, may form cryptic genes with DNA and dampen metabolic fluctuations. More recently they can increase adverse effects of hazardous chemicals and they can directly interfere with organisms. The book tries to relate effects to structural features.
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.
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."
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.
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." |
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