Channel width-flow discharge relationships for rills and gullies
Belgium ; Discharge ; Europe ; Gully erosion ; Italy ; Land use ; Rillwash ; Runoff ; Slope ; Soil erosion ; Spain ; Water erosion
In order to investigate the width-discharge relationships for rills and gullies, a new method is proposed based on field measurements of widths of concentrated-flow erosion channels both upstream and downstream of channel junctions. A total of 322
rill and gully channel junctions with various soils and land use types were investigated in Belgium, Italy and Spain. The obtained data confirmed the existence of the power relationship for rills and gullies, with the exponent varying from 0.43
Effect of slope on the growth and migration of headcuts in rills
Gully erosion ; Mississippi ; Rainfall simulation ; Rillwash ; Sediment budget ; Slope gradient ; Soil erosion ; United States of America ; Watershed
Experiments were conducted to examine soil erosion by headcut development and upstream migration in rills typical of upland areas. Soil material, simulated rain, overland flow discharge, and initial headcut height were held constant in each
Interrill and rill erodibility in the northern Andean Highlands
Andes ; Erodibility ; High mountain ; Mathematical model ; Mountain ; Peru ; Rainfall simulation ; Rillwash ; Soil erosion ; Water erosion
The main aim of this study is to determine the interrill and rill erodibility values for a northern Andean highland watershed in Peru and to compare field measurements with existing models that describe erodibility : equations used by the Water
Flume experimental evaluation of the effect of rill flow path tortuosity on rill roughness based on the Manning–Strickler equation
Channel geometry ; Experimentation ; Mathematical model ; Model ; Rillwash ; Runoff ; Water erosion
The aim of this study is to evaluate the effect of rill morphology on roughness and hence to assess the Manning–Strickler roughness coefficient (kSt) by rill morphological data. A laboratory experiment was set up to analyse rill hydraulics
and roughness of I.) Free Developed Rill (FDR) flows and II.) Straight Constrained Rill (SCR) flows in the flume. It is highlighted that rill roughness was highly variable and relates to rill morphology. The AA. conclude that flow path tortuosity can be used
Agropedology ; Cultivated land ; Europe ; Gully erosion ; Land use ; Northwestern Europe ; Rillwash ; Soil conservation ; Soil erosion ; Soil properties ; Watershed
This study analyses the between-catchment variability of rill volumes produced by concentrated flow erosion during winter in the northern part of the Paris Basin. The working hypotheses were that 1) runoff concentrates along channels determined
by topography or by agricultural practices; 2) rill length is a major component of rill volume variability on a catchment scale; 3) rill cross-sectional areas are controlled by the size of upslope runoff-contributing areas connected to the corresponding channels
. Catchment erosion rates were estimated by adding together the predicted rill volumes for each segment within the catchment.
Two-dimensional modelling of the within-field variation in rill and gully geometry and location related to topography
Agricultural practice ; Belgium ; Cultivated land ; Erosion rate ; Gully erosion ; Loess ; Model ; Rillwash ; Slope ; Slope gradient ; Soil erosion
This paper relates the within-field variation in rill erosion rate to topographic attributes and derives a predictive equation between rill erosion rate and topography in a two-dimensional context. The AA. also investigate whether it is possible
to delineate the areas prone to rill and ephemeral gully formation based on a topographic threshold condition, and investigate the extent to which the predictions can be improved by introducing the direction of cultivation into the model. To limit the effects
Observations on steep slopes in Rwanda reveal that human interventions on surficial drainage can introduce gullying on places where runoff normally leads to diffuse or ephemeral rill erosion.
The article is an overview of Bulla's theory of climatic geomorphology, focusing on the system of climatic geomorphologic zones. Climatic conditions of rill, gully and river erosion were analysed within the framework of this system. - (AM)
Rill systems on mudrock and sandstone in Alberta badlands were studied to examine progressive changes in material properties as smectic-rich mudrocks and sandstones undergo weathering, and the impact of seasonal changes in precipitation patterns
. Three plots with well developed rill systems on each unit were examined in May 2001 and 2003. In controlled laboratory conditions, depending on moisture input, different crust types developed on materials after 10 wetting-drying cycles.
The role of vegetation in the retardation of rill erosion
China ; Deforestation ; Erosion rate ; Gully erosion ; Land use ; Plant cover ; Rillwash ; Sediment budget ; Slope ; Soil erosion ; Southern China ; Vegetation
Large rills with catchment areas pose serious soil erosion problems to South China, after deforestation has exposed the deeply weathered granitic slopes to the impacts of tropical rainstorms. The purpose of this study is to determine
the effectiveness of vegetation in controlling the erosion of large rills in South China.
Water table control on rill initiation and implications for erosional response
Canada ; Cold area ; Erodibility ; Gully erosion ; Rillwash ; Slope ; Slope gradient ; Soil erosion ; Soil moisture ; Toronto ; Water erosion
On sloping sandy agricultural soil sites near Toronto, Canada, summer storms adequate to generate runoff occur frequently, but rill development occurs mainly in spring when snowmelt or rainfall-induced runoff occurs above frozen subsoil
. This suggests that on low and moderate slopes on these soils rill initiation is controlled primarily by hydraulic impedance close to the surface, rather than critical hydraulic conditions in runoff. Laboratory flume experiments were carried out on 10 m slopes
). It is concluded that calcium replaces sodium in the crust during leaching, leaving a calcic crust, and a sub-crust that is sodic and prone to subsequent pipe enlargement. Rill morphology in these materials also suggests that rills develop from these pipes when
The measurement and modelling of rill erosion at angle of repose slopes in mine spoil
Australia ; Digital elevation model ; Gully erosion ; Mine ; Model ; New South Wales ; Rehabilitation ; Rillwash ; Simulation ; Slope ; Soil erosion
This study examines the ability of a terrestrial laser scanner to quantify rills that have developed on fresh and homogeneous mine spoil on an angle of repose slope. It also examines the ability of the SIBERIA erosion model to simulate the rill's
spatial and temporal behaviour. Results show that while the overall hillslope morphology was captured by the laser scanner, with the morphology of the rills being broadly captured, the characteristics of the rills were not well defined. These results
demonstrate that an even greater density of points is needed to capture sufficient rill morphology. Nevertheless, SIBERIA simulations of the hillslope demonstrated that the model was able to capture rill behaviour in both space and time when correct model