Hillslope hydrology and stability ning lu colorado school of mines jonathan godt united states geological survey, colorado about the book landslides are caused by a failure of the mechanical balance within hillslopes. The chapter closes with thoughts on new dimensions and directions of hillslope hydrology and research avenues to follow for the future. Feb 03, 1983 hillslope materials and processes book. The aim of this chapter is to provide an overview on todays conceptual models of processes at the hillslope scale and to examine the factors driving these mechanisms. This second edition has the same general purpose as the first edition. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Stay connected usda in facebook nrcs in twitter nrcs in youtube nrcs in mail usda in flicker. Hillslope runoff processes and models sciencedirect. Runoff mechanisms in this lecture, we take a broad view of hillslope any parts of a. Hillslope physics physical properties of regolith a. Slope processes and landforms hillslopehydrology why hillslope hydrology.
Class notes 8 mass wasting and hillslope processes i. On the basis of the different threshold theories, we derive expressions for the relationships between drainage density and environmental factors such as rainfall, relief, and mean erosion rate. Throughout the text emphasis is placed on the problems of data collection in the field and on the reliability of interpretations. This is the first part of my lecture at praia a mare summer school in 20. An acceleration larger than this value initiates sliding. Both the fundamentals of erosion and slope stability are discussed in this chapter with respect to processes, causes and impacts. These experiments have documented hillslope failures and knickpoints as common erosional processes within laboratory drainage basins hasbargen, 2003. This book is intended for students who approach the stud. Hillslope processes, drainage density, and landscape. The longterm response of hills and valleys to changes in climate depends on a variety of physical factors.
The text attempts to integrate the relevant subject matter from these disciplines from the point of view of an earth scientist. Hillslope materials and processes michael john selby, a. Aug 01, 2016 presented by, this video looks at engineering materials, which are divided into four key areas. View class notes 8 from es 322 at western oregon university. Lecture notes surface processes and landscape evolution earth. Presented by, this video looks at engineering materials, which are divided into four key areas. This book integrates the approaches of geologists, geomorphologists and engineers to the study of hillslopes. The role of soil processes in determining mechanisms of slope. Geomorphic processes geomorphology shaping the earths crust duration. During most of the 20th century three models of hillslope evolution were widely diffused. Understand the contribution of groundwater to storm runoff. All part of the land surface are linked in the flow of water, solutes and sediment through the drainage basin system. Channel processes are more important in higherorder streams. This book presents a cuttingedge quantitative approach to understanding hydromechanical processes across variably saturated hillslope environments and to the study and prediction of.
Then you can start reading kindle books on your smartphone, tablet, or computer no kindle device required. Pdf hillslope materials and processes download online. The impact of natural hillslope processes is important and is currently strongly influenced by human activity due to land use change and vegetation removal, and is becoming even greater due to climate change. Hillslope processes occur on a complex template, composed of a wide array of topographies, climates, geologies, and ecosystems chapter 2, physiography of british columbia. Erosion and sedimentation in a semiarid environment channel and hillslope processes in a semiarid area, new mexico by luna b. A variety of processes exist by which materials can be moved through the hillslope system. The role of subsurface flow in hillslope and stream bank erosion. We show a table with the employed notation at the end of the paper. Apr 06, 2014 this is the first part of my lecture at praia a mare summer school in 20. Hillslope materials and processes 2nd edition by m. A rill is a shallow channel in some soil, created by the erosion of flowing water.
Hillslope materials and processes transportation research board. Nearsurface deposits and hillslope evolution of the adriatic piedmont. Hillslope soils and organic matter dynamics within a native american agroecosystem on the colorado plateau j. Hillslope soils and organic matter dynamics within a native. The dominant geomorphic processes are hillslope erosion and deposition. Soil erodibility and processes of water erosion on hillslope. Hillslope runoff processes at any point on a hillslope surface, or within the soil, water is moving under potential gradients due to both gravity and water pressure or tension. Ridge and valley spacing are set by the balance of sediment moving down hillslopes or being washed out. Richards equation and hillslope hydrology part 1 youtube. Bedrock landsliding is a dominant geomorphic process in a number of highrelief landscapes, yet is neglected in landscape evolution models. Myrich abstract ephemeral washes having drainage areas from a few acres to 5 square miles are shown by actual measurement to be ac cumulating sediment on the streambed. Hence, basic interactions between stream incision and failures can be studied in a controlled environment, and they provide a suitable setting to test the idea that knickpoints impose a spatial. Until the 1950s models of hillslope form evolution were central in geomorphology. Experimental evidence for hillslope control of landscape.
Hillslope soils and organic matter dynamics within a. The role of soil processes in determining mechanisms of. The focus will be on compiling recent findings on the dominant controls of hillslope runoff processes to meet the need of identifying underlying principles. This balance is governed by two coupled physical processes.
Get your kindle here, or download a free kindle reading app. In soilmantled parts of the world, the geomorphic and hydrologic processes involved in hillslope sediment transport are strongly influenced by soil properties. Since publication of the first edition, not only has knowledge advanced but an interdisciplinary approach to much of the research has become. Bedrock landsliding is an important process in the evolution of diverse landscapes 15. Model simulations using available field data were compared to field observations of rainfallpore pressure responses and were found to be in reasonable agreement. Frequent small slides produce irregular hillslopes, on which steep toes and head scarps persist until being cleared.
The mechanical balance within hillslopes is governed by two coupled physical processes. Under the natural condition, water, sediments, and rocks move down slope. Hillslope hydrology and stability landslides occur when hillslopes become mechanically unstable, because of meteorological and geologic processes, and pose a serious threat to human environments in their proximity. For practical purposes, water may be treated as incompressible, and continuity of mass or volume must be maintained, taking into account inputs and outputs, including. Worked examples of all mathematical analyses are provided. Hydropedological classification of south african hillslopes. In many areas, the dominant source of sediment is the stream bank itself. This book presents a cuttingedge quantitative approach to understanding hydromechanical processes across variably saturated hillslope environments and to the study and prediction of rainfallinduced landslides. Backfill deposits are made up of caothic and heterometric material. These processes are generically known as mass movement or mass wasting. The impact of natural hillslope processes is important and is currently strongly influenced by human activity due to land use change and vegetation removal. View notes 6hillslopes from ess 102 at morehead state university. Hillslope hydrology and stability oregon state university. Q3 q for main channel hydrology of 1st order streams are controlled by hillslope processes.
Following this thought erosion by the sea and lateral stream. Brown 1995, in a twodimensional model, incorporated both infiltration partitioning and overland flow into the hillslope flow model. Geomorphologists seek to understand why landscapes look the way they do, to understand. It generally formed by weathering of underline material and moves downslope due to gravitational processes. This book is intended for students who approach the study of hillslopes, and the rocks and soils on which they develop, from such traditional disciplines as. For more gentle slopes, gully erosion, which is a form of hillslope failure, can be a signifi cant source of stream sediment. These different hillslope processes alter both the visual appearance of the landscape and the predicted relationship between slope and contributing area.
Canadian journal of soil science canadian science publishing. Impacts of rainfall intensity and slope gradient on rill erosion processes at loessial hillslope. A physical model of sliding in beans is presented, in which incremental lowering of one wall simulates baselevel fall and generates slides. Click and collect from your local waterstones or get free uk delivery on orders over. Nearsurface deposits and hillslope evolution of the. Most models of landscape evolution, however, assume that diffusive processes shape hillslopes 4, 6 or that slopes are instantaneously lowered above some threshold. Rills can generally be easily removed by tilling the soil. Enter your mobile number or email address below and well send you a link to download the free kindle app. This book is intended for students who approach the study of hillslopes, and the rocks and soils on which they develop, from such traditional disciplines as geomorphology, geology, engineering, and soil science. May 12, 2011 the focus will be on compiling recent findings on the dominant controls of hillslope runoff processes to meet the need of identifying underlying principles. Selby 1985 water causes geomorphologicalchange by weathering, eroding and transporting earth materials. The modern understanding is that the evolution of slopes is much more complex than the classical models of. Likewise, models of bedrock landslides have ignored longterm hillslope evolution by discrete events 811. This separation of the less known surface and subsurface runoff yield processes and the better known and wellstudied soil waterplantatmosphere processes has already been defined as first order hillslope controlled and second order near surface controlled water uhlenbrook et al.
The modern understanding is that the evolution of slopes is much more complex than the classical models of decline, replacement and retreat imply. Slope is often nonuniform along the hillslope, with variations describing. The combined data set consisting of all soil failures shows that scar depth or deposit thickness does not vary with landslide area, whereas the median depths of soil landslide scars increase by less than one order of magnitude with increasing landslide area fig. The operation of mass movement processes relies upon the development of instability in the hillslope system. The present topography and soil thickness reflect a sensitive balance between weathering, erosion, and deposition. White abstract retention in alluviumderived soils of headwater ephemzuni farmers of western new mexico demonstrate knowledge eral streams. The stabilizing strength of hillslope materials depends on effective stress, which is diminished by rainfall. Hillslope processes hillslopes essentially cover the whole landscape. New dimensions of hillslope hydrology springerlink. In newmarks method one estimates the permanent displacement by doubleintegrating the parts of an earthquake accelerationtime history that exceed the critical acceleration jibson 1993. Approximately seventy per cent of the text is new, with many new figures and plates, which has enabled professor selby to provide a more comprehensive introduction than in the first edition to the nature of chemical bonding, the properties of mineral particles and fabrics of weak rock, rheology of rock and soil, hillslope hydrology, hillslope.
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