Handbook Of Erosion Modelling

The movement of sediment and associated pollutants over thelandscape and into water bodies is of increasing concern withrespect to pollution control, prevention of muddy floods andenvironmental protection. In addition, the loss of soil on site hasimplications for declining agricultural productivity, loss ofbiodiversity and decreased amenity and landscape value. The fate ofsediment and the conservation of soil are important issues for landmanagers and decision-makers. In developing appropriate policiesand solutions, managers and researchers are making greater use oferosion models to characterise the processes of erosion and theirinteraction with the landscape. A study of erosion requires one to think in terms ofmicroseconds to understand the mechanics of impact of a singleraindrop on a soil surface, while landscapes form over periods ofthousands of years. These processes operate on scales ofmillimetres for single raindrops to mega-metres for continents.Erosion modelling thus covers quite a lot of ground. This bookintroduces the conceptual and mathematical frameworks used toformulate models of soil erosion and uses case studies to show howmodels are applied to a variety of purposes at a range of spatialand temporal scales. The aim is to provide land managers and otherswith the tools required to select a model appropriate to the typeand scale of erosion problem, to show what users can expect interms of accuracy of model predictions and to provide anappreciation of both the advantages and limitations of models.Problems covered include those arising from agriculture, theconstruction industry, pollution and climatic change and range inscale from farms to small and large catchments. The book will alsobe useful to students and research scientists as an up-to-datereview of the state-of-art of erosion modelling and, through aknowledge of how models are used in practice, in highlighting thegaps in knowledge that need to be filled in order to develop evenbetter models.

Learn to create and use simulation models—the most reliable and cost-effective tools for predicting real-world results! The Handbook of Processes and Modeling in the Soil-Plant System is the first book to present a holistic view of the processes within the soil-plant-atmosphere continuum. Unlike other publications, which tend to be more specialized, this book covers nearly all of the processes in the soil-plant system, including the fundamental processes of soil formation, degradation, and the dynamics of water and matter. It also illustrates how simulation modeling can be used to understand and forecast multiple interactions among various processes and predict their environmental impact. This unique volume assembles information that until now was scattered among journals, bulletins, reports, and symposia proceedings to present models that simulate almost all of the processes occurring in the soil-plant system and explores the results that these models are capable of producing. With chapters authored by experts with years of research and teaching experience, the Handbook of Processes and Modeling in the Soil-Plant System examines: physical, chemical, and biological soil processes the soil formation and weathering process and its modeling the impact of radioactive fallout on the soil-plant system soil degradation processes and ways to control them water and matter dynamics in the soil-plant system growth and development of crops at various levels of production the potentials and limitations of using simulation models Students, educators, and professionals alike will find the Handbook of Processes and Modeling in the Soil-Plant System an invaluable reference on the soil-plant-atmosphere system and an ideal tool to help develop an effective decision support system.

The Universal Soil Loss Equation (USLE) enables planners to predict the average rate of soil erosion for each feasible alternative combination of crop system and management practices in association with a specified soil type, rainfall pattern, and topography. When these predicted losses are compared with given soil loss tolerances, they provide specific guidelines for effecting erosion control within specified limits. The equation groups the numerous interrelated physical and management parameters that influence erosion rate under six major factors whose site-specific values can be expressed numerically. A half century of erosion research in many States has supplied information from which at least approximate values of the USLE factors can be obtained for specified farm fields or other small erosion prone areas throughout the United States. Tables and charts presented in this handbook make this information readily available for field use. Significant limitations in the available data are identified.

TO THE MODEL EVALUATION 1. MODELLING SOIL EROSION BY WATER l 2 John Boardman and David Favis-Mortlock 1 School of Geography and Environmental Change Unit Mansfield Road University of Oxford Oxford OX1 3TB UK 2 Environmental Change Unit University of Oxford 5 South Parks Road Oxford OX1 3UB UK Introduction This volume is the Proceedings of the NATO Advanced Research Workshop 'Global Change: Modelling Soil Erosion by Water', which was held on II-14th September 1995, at the University of Oxford, UK. The meeting was also one of a series organised by the IGBP 1 GCTE Soil Erosion Network, which is a component of GCTE's Land Degradation Task (3.3.2) (Ingram et aI., 1996; Valentin, this volume). One aim of the GCTE Soil Erosion Network is to evaluate the suitability of existing soil erosion models for predicting the possible impacts of global change upon soil erosion. Due to the wide range of erosion models currently, in use or under development, it was decided to evaluate models in the following sequence Favis-Mortlock et al., 1996): • field-scale water erosion models • catchmenr-scale water erosion models • wind erosion models • models with a landscape-scale and larger focus. As part of this strategy, the first stage of the GCTE validation of field-scale erosion models was carried out at the Oxford NATO-ARW. I A list of Acronyms fonns Appendix A.

This publication deals with soil erosion and sedimentation. Soil erosion and associated sediment deposition are natural landscape-forming processes that can be greatly accelerated by human intervention through deforestation, overgrazing, and non-sustainable farming practices. Soil erosion and sedimentation may not only cause on-site degradation of the natural resource base, but also off-site problems— downstream sediment deposition in fields, floodplains and water bodies, water pollution, eutrophication and reservoir siltation, etc. —with serious environmental and economic impairment. There is an urgent need for accurate information to quantify the problem and to underpin the selection of effective soil-conservation technologies and sedimentation-remediation strategies, including assessment of environmental and economic impacts. Existing classical techniques to document soil erosion are capable of meeting some of these needs, but they all possess important limitations. The quest for alternative techniques for assessing soil erosion, to complement existing methods, directed attention to the use of environmental radionuclides, in particular fallout as tracers to quantify rates and establish patterns of soil redistribution within the landscape. The concept of a project on the use of environmental radionuclides to quantify soil redistribution was first formulated at an Advisory Group Meeting convened in Vienna, April 1993, by the International Atomic Energy Agency (IAEA).

Introduction and history; Rainfall-runoff erosivity factor (R); Soil erodibility factor (K); Slope length and steepness factors (LS); Cover-management factor (C); Support practice factor (P); RUSLE user guide; Coversion to SI metric system; Calculation of EI from recording-raingage records; Estimating random roughness in the field; Parameter values for major agricultural crops and tillage operations.

Accelerated degradation of soils and surface waters produce increasing problems in many parts of the world. Within this context, the book addresses the topic Application of Physically Based Soil Erosion Models in order to present some essential tools for improving land-use strategies and conservation measures. Over the last 20 years, the need for more accurate assessments of soil losses and sediment yields has led to the development of some highly complex, process-based soil erosion models. In 14 papers, specialists from 5 European countries, the USA and Brazil report on practical applications of these models and give insight into the latest developments. This book will help to implement state-of-the-art soil erosion prediction technologies within soil and water conservation planning and assessment. Hence, the book should be of special interest to agricultural and environmental engineers, hydrologists, soil scientists and geoscientists.