Download or read book Frequency of freeze thaw cycles bulk density and saturation effects on soil surface shear and aggregate stability in resisting water erosion written by S. N. Asare and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Change and Geomorphic Hazards in Forests written by Roy C. Sidle and published by CABI. This book was released on 2002-09-30 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews current knowledge of most types of geohazards in forested areas. The 11 chapters cover hydrologic impacts, including flooding and soil erosion, desertification in Mediterranean Europe and Africa, landslides, and hazards in mangrove forests and along shorelines. Examples covered are from all five continents.
Download or read book Soils and Fertilizers written by and published by . This book was released on 1998-07 with total page 1294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Landslides written by Roy C. Sidle and published by American Geophysical Union. This book was released on 2006-01-10 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 18. Landslides are a constant in shaping our landscape. Whether by large episodic, or smaller chronic, mass movements, our mountains, hills, valleys, rivers, and streams bear evidence of change from landslides. Combined with anthropogenic factors, especially the development and settlement of unstable terrain, landslides (as natural processes) have become natural disasters. This book charts our understanding of landslide processes, prediction methods, and related land use issues. How and where do landslides initiate? What are the human and economic consequences? What hazard assessment and prediction methods are available, and how well do they work? How does land use, from timber harvesting and road building to urban and industrial development, affect landslide distribution in time and space? And what is the effect of land use and climate change on landslides? This book responds to such questions with: • Synopses of how various land uses and management activities influence landslide behavior • Analyses of earth surface processes that affect landslide frequency and extent • Examples of prediction techniques and methods of landslide hazard assessment, including scales of application • Discussion of landslide types and related costs and damages Those who study landslides, and those who deal with landslides, from onset to after-effects—including researchers, engineers, land managers, educators, students, and policy makers—will find this work a benchmark reference, now and for years to come.
Download or read book Ground Freezing Effects on Soil Erosion of Army Training Lands written by and published by . This book was released on 1998 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two areas were monitored at the Yakima Training Center (YTC) in central Washington to measure changes in M1A2 Abrams (M1) tank-rut surface geometry, and in- and out-of-rut saturated hydraulic conductivity (Ksubfs), soil penetration resistance (SPR), and bulk density over the 1995-1996 winter. Profile meter data show that rut cross-sectional profiles smoothed significantly and that turning ruts did so more than straight ruts. Rut edges were zones of erosion and sidewall bases were zones of deposition. Ksubfs values were similar in and out of ruts formed on soil with 0-5 percent water by volume, but were lower in ruts formed on soil with about 15 percent water. Mean SPR was similar in and out of ruts from 0- to 5-cm depth, increased to 2 MPa outside ruts and 4 MPa inside ruts at 10- to 15-cm depth, and decreased by 10-38 percent outside ruts and by 39-48% inside ruts at the 30-cm depth. Soil bulk density was similar in and out of ruts from 0- to 2.5-cm depth, and below 2.5 cm it was generally higher in ruts formed on moist soil, with highest values between 10- and 20-cm depth. Conversely, density in ruts formed on dry soil was similar to out-of-rut density at all depths. This information is important for determining impacts of tank ruts on water infiltration and soil erosion, and for modifying the Revised Universal Soil Loss Equation (RUSLE) and the Water Erosion Prediction Project (WEPP) models to more accurately predict soil losses on Army training lands.
Download or read book Quantifying the Effect of a Freezethaw Cycle on Soil Erosion written by and published by . This book was released on 2004 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we quantitatively tested the hypothesis that soil freeze-thaw(FT) processes significantly increase the potential for upland hillslope erosion during runoff events that follow thaw. We selected a frost-susceptible silt to obtain an upper bound on FT effects, and completed three series of six experiments each to quantify differences in soil erodibility and rill development for bare soil following a single FT cycle. Each series represented a specific soil moisture range: 16-18%, 27-30%, and 37-40% by volume, with nominal flow rates of 0.4, 1.2, and 2.4 L/min and slopes of 8 and 15 . Each experiment used two identical soil bins, one a control (C) to remain unfrozen, the other to be frozen and thawed. Standard soil characterization tests did not detect significant differences between the FT and C bins. Experimental results were closely related to conditions of the experiment, imposing a requirement for minimum differences in soil weight, bulk density, and soil moisture through each series. We measured cross-sectional geometry of an imposed straight rectangular rill before each experiment, sediment load during, and rill cross sections after. Changes in cross section provided detailed measures of erosion at specific locations along the rill, while sediment load from time series runoff samples integrated the rill erosion. Several parameters, including average maximum rill width, average maximum rill depth, rill cross-section depth measures, and sediment load all followed similar trends. Each was greater in the FT than in the C, with values that generally increased with slope and flow. However, soil moisture was the only parameter that affected the FT/C relationship. For example, average sediment load grouped by soil moisture provided FT/C ratios of 2.4, 3.0, and 5.0 for low, mid, and high moisture, respectively. In contrast, a "dry" experiment at 4.4 soil moisture had FT/C of 1.02 for sediment load.
Download or read book The Effect of Freeze thaw Cycles on Soil Respiration and Nitrogen Dynamics as In fluenced by Soil Structure Aggregate Size and Water Content written by Bangwei Zhang and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of soil structure and aggregation in influencing soil respiration and N dynamics in soils undergoing freeze-thaw cycles, as influenced by water content, is poorly known. Surface soil with a texture of sandy loam was collected from an agriculture field in Atlantic Canada. Two studies were undertaken. The first study determined the influence of soil structure (whole / crushed soil) and water content (35%, 60%, and 85% water-filled pore space) on soil respiration and nitrogen dynamics during freezing and thawing of the soil. The second study determined the role of different aggregate size fractions (0~0.25, 0.25~4, and 4~8 mm) on the freeze-thaw effect. The research found microbial metabolism is more limited by environmental conditions than by the substrate availability. Crushing altered structural characteristics and caused changes in substrate solubilization and / or microbial utilization of substrates during freezing and thawing. Furthermore, freezing and thawing did not influence the denitrification of the whole soil, but enhanced denitrification in soils where aggregates were crushed. At 60% WFPS, the interaction among aggregate crushing and freeze-thaw increased denitrification. Also, the impact of freeze-thaw was greater on soil respiration and N mineralization in medium size aggregates (0.25~4mm). Freezing and thawing improved de-nitrification in aggregates on all three size fractions. This project provided new information on the effects of freeze-thaw on soil carbon and nitrogen dynamics as influenced by soil structure and water content. This information will be critical in assessing the impact of climate change in soil carbon and nitrogen dynamics in temperate regions.
Download or read book The Effects of Freezing and thawing on Structural Strength of Selected Bituminous Stabilized Base Course written by Abbas Ghane-Bassiri and published by . This book was released on 1966 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of a Freeze thaw Cycle on the Dry Bulk Density of a Soil written by Robert George Cessford and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary purpose of this investigation was to examine one aspect of the compaction problem, viz. the effect of a freeze-thaw cycle on the bulk density of a soil. Moisture content, temperature (freezing rate) and initial density were parameters considered in the project. A moisture-density meter was designed and built for the purpose of measuring bulk density and moisture content non-destructively. Analysis of variance and multiple regression techniques were used to analyze the data. The following results and conclusions were obtained: 1. Non-destructive measurement of soil bulk density and moisture content was achieved using a dual energy gamma transmission technique. 2. Significant density changes were caused by an interaction of the parameters temperature x initial density. 3. Density changes due to the levels of the factors considered in the experiment were small, indicating little loosening of compacted soil during a freeze-thaw cycle. 4. Prediction of density responses in the field would not be possible on the basis of results obtained in this experiment.
Download or read book Soil Freeze Thaw Effects on Bank Erosion and Stability Connecticut River Field Site Norfolk Vermont written by and published by . This book was released on 2005 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bank recession resulting from surficial erosion and mass failure is a consequence of hydraulic forces and geotechnical processes. One important set of geotechnical processes in regions where seasonal frost forms is soil freeze-thaw (FT) cycling and associated ground-ice growth and melt. In cold regions soil FT processes usually cause more bank recession annually than other processes. The magnitude of FT effects is variable, depending on soil type, water content, and freezing rate. The banks along the Connecticut River at Norwich, Vermont are unstable and receding in certain locations. A 40-m-long segment of unstable east-facing bank was selected for intensive monitoring along with nearby north- and south-facing bank locations. This technical note documents our field observations, measurements, and analysis encompassing three years of monitoring. Our data acquisition equipment, focusing on FT processes, was installed in November through December 2002, and data collection continued through July 2005. The primary purposes of the field program were to evaluate: 1) the depth and duration of soil FT, and the effect of orientation and soil moisture on these parameters, 2) the effects of FT on soil strength and erosional processes, 3) the timing and depth of any slope failures of the east-facing bank, and 4) the hypothesis of soil FT as a primary contributor to slope failure. Results indicate that bank orientation and soil moisture can have dramatic effects on the depth, extent, and duration of soil freezing. FT of the monitored banks generally affected the soil to a depth of 0.75 m below the surface. The shallow nature of the bank erosion at this site is consistent with FT weakening of near surface soils. Subsequent rainfall and runoff are then able to readily move these sediments down slope causing progressive bank recession.
Download or read book Principles of Soil Conservation and Management written by Humberto Blanco-Canqui and published by Springer Science & Business Media. This book was released on 2008-09-16 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Principles of Soil Management and Conservation” comprehensively reviews the state-of-knowledge on soil erosion and management. It discusses in detail soil conservation topics in relation to soil productivity, environment quality, and agronomic production. It addresses the implications of soil erosion with emphasis on global hotspots and synthesizes available from developed and developing countries. It also critically reviews information on no-till management, organic farming, crop residue management for industrial uses, conservation buffers (e.g., grass buffers, agroforestry systems), and the problem of hypoxia in the Gulf of Mexico and in other regions. This book uniquely addresses the global issues including carbon sequestration, net emissions of CO2, and erosion as a sink or source of C under different scenarios of soil management. It also deliberates the implications of the projected global warming on soil erosion and vice versa. The concern about global food security in relation to soil erosion and strategies for confronting the remaining problems in soil management and conservation are specifically addressed. This volume is suitable for both undergraduate and graduate students interested in understanding the principles of soil conservation and management. The book is also useful for practitioners, extension agents, soil conservationists, and policymakers as an important reference material.
Download or read book The Influence of Natural simulated Freeze thaw Cycles on Aggregate Stability in Sandy and Clayey Soils in Norway written by Anne Schols and published by . This book was released on 2016 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lockhart and Wiseman s Crop Husbandry Including Grassland written by Steve Finch and published by Elsevier. This book was released on 2002-06-05 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1966, Lockhart and Wiseman's Crop Husbandry Including Grassland has established itself as the standard crop husbandry text for students and practitioners alike. Radically revised and expanded, and with a new team of authors, the eighth edition confirms and extends its reputation.Part one looks at the basic conditions for crop growth with chapters on plant structure and growth, soil analysis and management, and the use of fertilisers and manures. There is also a new chapter on the influence of climate and weather. Part two surveys general aspects of crop husbandry. As well as a discussion of cropping techniques, there are new chapters on the important new areas of integrated crop management and organic crop husbandry, as well as discussion of seed selection and production. Part three then looks at how these general techniques are applied to particular crops, with chapters on cereals, root crops, fresh harvested crops, forage crops and combinable break crops. Part four considers the use of grassland with chapters on classification, sowing and management, grazing and conservation for winter feed.Lockhart and Wiseman's Crop Husbandry Including Grassland remains the standard text for general agriculture, land management and agri-business courses, and is a valuable practical reference for the farming industry. - The eighth edition has been widely expanded and remains the standard text for general agriculture, land management and agri-business courses - Includes new chapters on cropping techniques, integrated crop management and quality assurance, seed production and selection and the influence of climate - Discusses basic conditions for crop growth, how techniques are applied to particular crops, the influence of weather and the use of grassland
Download or read book Handbook for Stabilization of Pavement Subgrades and Base Courses with Lime written by Dallas N. Little and published by . This book was released on 1995 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agricultural Soil Mechanics written by A. J. Koolen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compared with forces occurring in soil mechanics problems in civil engineering, the forces that are applied to soil in farming operations generally have a short duration, less than a few seconds, a small loaded area, no more than a few square decimeters, and small intensities, 10 bar being a high value. On the other hand, soil properties vary widely between those of a weak mud and a stone-like dry soil. Tillage and related applications of force to soil are practiced worldwide in farming. Tillage operations are performed on one hectare of land for every three human beings. This means that for the food production for each individual daily, something like one cubic meter of soil is stirred, or about 20 times his body weight. Theoretical knowledge of this most common human activity, which largely determines the surface shape of the fertile part of the earth, is still very limited. In this book the authors have tried to give an outline of the present state of the art. One of the starting points was a course in soil dynamics taught by the authors at the Agricultural University at Wageningen, The Netherlands. We hope to reach interested readers who have no more theoretical knowledge than high school level, as well as readers who want to go beyond the level of a third year university student. For the chapter on wheels and tires we received substantial support from F. G. J. Tijink of the Tillage Laboratory at Wageningen.
Download or read book Geotechnical Applications written by Anirudhan I.V. and published by Springer. This book was released on 2018-06-12 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select proceedings of the annual conference of the Indian Geotechnical Society. The conference brings together research and case histories on various aspects of geotechnical engineering and geoenvironmental engineering. The book presents papers on geotechnical applications and case histories, covering topics such as (i) shallow and deep foundations; (ii) stability of earth and earth retaining structures; (iii) rock engineering, tunneling, and underground constructions; (iv) forensic investigations and case histories; (v) reliability in geotechnical engineering; and (vi) special topics such as offshore geotechnics, remote sensing and GIS, geotechnical education, codes, and standards. The contents of this book will be of interest to researchers and practicing engineers alike.
Download or read book Lime Stabilization written by and published by Transportation Research Board National Research. This book was released on 1987 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many years, various forms of lime, including products with varying degrees of purity, have been utilized successfully as soil stablizing agents. The state of the art in lime treatment based on a comprehensive analysis of current practice and technical literature is presented in this report. References are included for more information.
