SMODERP — A Simulation Model of Overland Flow and Erosion Processes

Soil Erosion ◽  
2000 ◽  
pp. 135-161 ◽  
Author(s):  
T. Dostál ◽  
J. Váška ◽  
K. Vrána
Keyword(s):  
Simulation Model ◽  
Overland Flow ◽  
Erosion Processes

Soil erosion and runoff in improved pastures of the Clwydian Range, North Wales

1998 ◽  
Vol 130 (4) ◽  
pp. 473-488 ◽  
Author(s):  
P. A. JAMES ◽  
R. W. ALEXANDER
Keyword(s):  
Particle Size ◽  
Soil Erosion ◽  
Overland Flow ◽  
Ground Cover ◽  
Erosion Processes ◽  
North Wales

Studies of soil erosion in upland and marginal upland Britain are reviewed. Processes affecting soil erosion and runoff are described in marginal upland improved pastures of differing age in the Clwydian Hills, including one which was cultivated twice during the study period. A Gerlach-type trough was designed for trapping sediment and filtered runoff from bounded plots and for operating under grazing. Erosion and runoff amounts are interpreted in the light of ground cover, rainfall amounts and intensity, the action of grazing stock and other animals, and other influences. The chief erosion processes are the action of animals and surface wash by unconcentrated overland flow; no rilling occurred. The significance of particle size of eroded sediment is discussed.

Soil erosion processes. I. The relative importance of rainfall detachment and dunoff entrainment

Soil Research ◽  
1991 ◽  
Vol 29 (5) ◽  
pp. 671 ◽  
Author(s):  
APB Proffitt ◽  
CW Rose
Keyword(s):  
Soil Erosion ◽  
Overland Flow ◽  
Water Flux ◽  
Equilibrium Concentration ◽  
Sediment Concentration ◽  
Soil Types ◽  
Relative Importance ◽  
Runoff Water ◽  
Erosion Processes ◽  
Volumetric Flux

Experiments carried out in a simulated-rainfall tilting-flume facility are reported in which sediment concentrations (c) in runoff water resulting from overland flow only, or from a combination of rainfall and overland flow, were measured under controlled conditions using a series of slopes (0.1, 05, 1, 3 and 5%). The mixture of rainfall (of rate 100 mm h-1) and runon of water at the top of the flume were arranged to provide a constant volumetric flux (1.0x10-3 m3 m-l s-1) at exit from the 5.8 m long flume. Two contrasting soil types were studied: a cracking clay (black earth or vertisol), and a slightly dispersive sandy clay loam (solonchak or aridisol). Two major processes which can contribute to soil erosion under rainfall are rainfall detachment and runoff entrainment. For both soil types, c was generally highest for the steepest slope and decreased with slope. For constant rainfall and/or runoff conditions, c generally decreased with time until an equilibrium concentration was reached. At this equilibrium, the relative importance of rainfall detachment and entrainment in terms of soil loss was dependent on soil type and streampower which incorporates effects of slope and water flux. For streampowers <0.1 W m-2 for the black earth, and <0.3 W m-2 for the solonchak, the greatest contribution to c was by rainfall detachment, whilst at greater streampowers entrainment was the dominant contributor to c. At any streampower, the contribution by rainfall detachment was greater for the weakly structured solonchak than for the well aggregated black earth. At lower strearnpowers, the interaction between erosion processes was found to give higher c than the sum of both sediment concentrations resulting from the separately occurring processes. At streampowers greater than approximately 0.5 W m-2, rainfall reduced eroded sediment concentration by suppressing rill development. The findings in this study suggest that both runoff entrainment and rainfall detachment can contribute to sediment concentration from 'interrill' areas.

scholarly journals Aplicação da Micromorfologia de Solos ao Estudo de Sedimentos Alúvio-Coluviais em Cabeceiras de Vale

2006 ◽  
Vol 33 (2) ◽  
pp. 3 ◽  
Author(s):  
GLAUCIA MARIA DOS SANTOS SILVA FERREIRA ◽  
MARCELO ACCIOLY TEIXEIRA DE OLIVEIRA
Keyword(s):  
Overland Flow ◽  
Gully Erosion ◽  
Aerial Photographs ◽  
Sedimentary Structures ◽  
Erosion Processes ◽  
Hillslope Evolution ◽  
Common Process ◽  
Geomorphological Units ◽  
The Relationship ◽  
Micromorphological Analysis

 Previous work on the role played by valley head areas in humid regions brought to light geomorphological units of the drainage net in which erosion and sedimentation would tend to be recurrent in time and space. Valley heads studied in Brazil had already proved to be very sensible to gully erosion processes, which, besides its importance to land degradation, also is a common process of hillslope evolution on humid regions. Gully erosion carries out from slopes important amounts of sediments, which may either, accumulate as proximal colluvium and alluvium or be conveyed through the drainage net. When colluvium and alluvium accumulate in proximal areas sedimentary structures may be preserved allowing the study of evolutionary processes. This paper is an attempt to apply micromorphological analysis to the study of the sedimentary structures preserved in gullied hillslopes of some southern Brazilian areas. The deposits are dated either in accordance to the supposed age of the gully incision, as estimated by aerial photographs, or by the record, in the field, of the depositional event. As a result, the age of the study deposits ranges from about 200 to 30 years, including fresh sediments just deposited one day before sampling. The paper stresses the relationship between macroscopic structures and micromorphological parametrical description, emphasizing interpretation of sedimentary structures as the result of variable overland flow rates on the gullied hillslopes.

scholarly journals Effects of rainfall, overland flow and their interactions on peatland interrill erosion processes

2018 ◽  
Vol 43 (7) ◽  
pp. 1451-1464 ◽  
Author(s):  
Changjia Li ◽  
Joseph Holden ◽  
Richard Grayson
Keyword(s):  
Overland Flow ◽  
Erosion Processes ◽  
Interrill Erosion

scholarly journals Investigation of Soil Erosion from Bare Steep Slopes of the Humid Tropic Philippines

2005 ◽  
Vol 9 (5) ◽  
pp. 1-30 ◽  
Author(s):  
A. L. Presbitero ◽  
C. W. Rose ◽  
B. Yu ◽  
C. A. A. Ciesiolka ◽  
K. J. Coughlan ◽  
...  
Keyword(s):  
Soil Loss ◽  
Overland Flow ◽  
Soil Surface ◽  
Infiltration Rate ◽  
Bare Soil ◽  
The Philippines ◽  
Roughness Coefficient ◽  
Storm Events ◽  
State College ◽  
Erosion Processes

Abstract At the Visayas State College of Agriculture (ViSCA) on the island of Leyte in the Philippines, hydrologic and soil-loss measurements were recorded for 32 erosion events over 3 yr on three 12-m-long bare soil plots with slopes of approximately 50%, 60%, and 70%. Measurements included rainfall and runoff rates at 1-min intervals, total soil lost per event from the plot, rill details when observed after an erosion event, and soil settling-velocity characteristics. Storm events are characterized by high rainfall rates but quite low rates of runoff, because of the consistently high infiltration rate of the stable clay soil (an Oxic Dystropept). Both observation and modeling indicated that overland flow is commonly so shallow that much of the soil surface is likely to be unsubmerged. For the 70% slope plot, half the events recorded mean sediment concentrations from 100 to 570 kg m−3. A somewhat constant hydrologic lag between rainfall and runoff is used to estimate a Manning’s roughness coefficient n of about 0.1 m−1/3 s, a value used to estimate velocity of overland flow. Possible effects of shallow flows and high sediment concentrations on existing erosion theory are investigated theoretically but are found to have only minor effects for the ViSCA dataset. A soil erodibility parameter β was evaluated for the data whenever rilling was recorded following an erosion event. The values of β indicate that, except for events with higher stream powers, other erosion processes in addition to overland flow could have contributed to soil loss from erosion plots in a significant number of events.

scholarly journals Soil Erosion and Controls in the Slope-Gully System of the Loess Plateau of China: A Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Bingbing Zhu ◽  
Zhengchao Zhou ◽  
Zhanbin Li
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Overland Flow ◽  
Vegetation Pattern ◽  
Sediment Source ◽  
The Loess Plateau ◽  
Erosion Process ◽  
Slope Length ◽  
Base Level ◽  
Erosion Processes

The Loess Plateau has long been suffering from serious soil erosion of which erosion from the slope-gully system is now dominant. The slope-gully system is characterized with distinctive erosion distribution zones consisting of inner and inter gully areas wherein erosion patterns spatially vary, acting as both sediment source and the dominant sediment and water transport mechanism. In this paper, a substantial body of research is reviewed concentrating on the soil erosion processes and control practices in the slope-gully system. The inner gully area is identified as the main sediment source while runoff and sediment from the inter-gully upland is found to significantly affect down slope erosion processes. Correspondingly, the protective vegetation pattern and coverage should be strategically designed for different erosion zones with an emphasis on the critical vegetation cover and pattern to reduce sediment yield of the whole slope-gully system. Check-dam could change the base level of erosion and reduce the slope length of the gully side, which will further decrease the possibility and magnitude of gravity erosion. We concluded that understanding the erosion processes and implementing erosion practices for the slope-gully system are of importance and require more research efforts that emphasize: 1) the influence of upland runoff on erosion processes at downslope; 2) the relationship between hydraulic characteristics of overland flow and erosion process at a slope-gully system scale; 3) physical mechanisms of different vegetation patterns on the slope-gully erosion process.

The role of the geometry and frequency of rectangular rills in the relationship between sediment concentration and stream power

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1359 ◽  
Author(s):  
B. Fentie ◽  
C. W. Rose ◽  
K. J. Coughlan ◽  
C. A. A. Ciesiolka
Keyword(s):  
Soil Erosion ◽  
Overland Flow ◽  
Sediment Concentration ◽  
Stream Power ◽  
Flume Experiments ◽  
Erosion Processes ◽  
Physically Based ◽  
The Relationship ◽  
Raindrop Impact

We examined, both experimentally and theoretically, whether rilling results in higher soil erosion than would have occurred without rilling. The possibility of rilling occurs when overland flow-driven erosion processes are dominant over erosion due to raindrop impact, and that is the situation assumed in this paper. Stream power (or a quantity related to stream power such as shear stress) is commonly used to describe the driving variable in flow-driven erosion. Five flume experiments were designed to investigate the relationship between stream power and sediment concentration and how this relationship is affected by the ratio of width to depth of flow (r), and the frequency or number of rills per metre width (N) of rectangular rills. This paper presents the results of these experiments and uses a physically based soil erosion theory to show that the results of the 5 flume experiments are in accord with this theory. This theory is used to investigate the effect of all possible rectangular rill geometries and frequencies on the maximum possible sediment concentration, i.e. the sediment concentration at the transport limit, by developing general relationships for the influence of r and N on sediment concentration. It is shown that increased stream power, which can be due to rilling, does not necessarily result in higher sediment concentration.

SIPSON – Simulation of Interaction between Pipe flow and Surface Overland flow in Networks

2005 ◽  
Vol 52 (5) ◽  
pp. 275-283 ◽  
Author(s):  
S. Djordjević ◽  
D. Prodanović ◽  
Č. Maksimović ◽  
M. Ivetić ◽  
D. Savić
Keyword(s):  
Simulation Model ◽  
Pipe Flow ◽  
Overland Flow ◽  
Field Measurements ◽  
Internal Boundary ◽  
Sewer System ◽  
Buried Structures ◽  
Runoff Hydrographs ◽  
The Mathematical Model ◽  
Looped Network

The new simulation model, named SIPSON, based on the Preissmann finite difference method and the conjugate gradient method, is presented in the paper. This model simulates conditions when the hydraulic capacity of a sewer system is exceeded, pipe flow is pressurized, the water flows out from the piped system to the streets, and the inlets cannot capture all the runoff. In the mathematical model, buried structures and pipelines, together with surface channels, make a horizontally and vertically looped network involving a complex interaction of flows. In this paper, special internal boundary conditions related to equivalent inlets are discussed. Procedures are described for the simulation of manhole cover loss, basement flooding, the representation of street geometry, and the distribution of runoff hydrographs between surface and underground networks. All these procedures are built into the simulation model. Relevant issues are illustrated on a set of examples, focusing on specific parameters and comparison with field measurements of flooding of the Motilal ki Chal catchment (Indore, India). Satisfactory agreement of observed and simulated hydrographs and maximum surface flooding levels is obtained. It is concluded that the presented approach is an improvement compared to the standard “virtual reservoir” approach commonly applied in most of the models.

Estimation of erosion model erodibility parameters from media properties

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 265 ◽  
Author(s):  
G. J. Sheridan ◽  
H. B. So ◽  
R. J. Loch ◽  
C. M. Walker
Keyword(s):  
Overland Flow ◽  
Prediction Models ◽  
Field Capacity ◽  
Stepwise Multiple Regression ◽  
Organic Carbon Content ◽  
Regression Equations ◽  
Sediment Delivery ◽  
Data Set ◽  
Erosion Rates ◽  
Erosion Processes

The aim of this research was to enable erodibility values for hillslope-scale erosion prediction models to be determined from easily measured media properties. Simulated rainfall and overland flow experiments were carried out on 34 soils and overburdens from 15 Queensland open-cut coal mines at The University of Queensland Erosion Processes Laboratory. Properties of the 34 media determined included aggregate stability, Atterberg limits, bulk density, cation exchange capacity, dispersion ratios, electrical conductivity, exchangeable sodium percentage, organic carbon content, pH, texture, and water content at field capacity and wilting point. Correlation and stepwise multiple regression procedures were used to determine those media properties that could best be used to predict rill and interill erodibility. Correlations between media properties and sediment delivery at each of 5, 10, 15, 20, and 30% slope revealed that different media properties were correlated with erosion rates at different slopes. A media property could show a strong correlation with erodibility at 30% slope, and a low correlation at 5% slope. Splitting the data set into soils only, and overburdens only, showed that properties that were positively correlated with erosion rates for one group could be negatively correlated for the other group. Therefore, in this study, erodibility could not be explicitly linked to one set of media properties for all medium types and erosive conditions. It was concluded that a single regression equation could not be used to predict erodibility under all conditions. Instead, 4 equations were developed to predict rill and interill erodibility, for soils and overburdens separately. The need for separate regression equations was attributed to the presence of different erosive sub-processes for specific combinations of medium type and slope gradient.

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