Runoff and sediment losses from rough and smooth soil surfaces in a laboratory experiment
Agricultural practice ; Indiana ; Perception ; Rainfall simulation ; Roughness ; Runoff ; Slope gradient ; Soil erosion ; United States of America ; Water erosion
The aim of this study was to measure the effects of initial surface roughness on runoff and erosion under controlled laboratory conditions. Initially, rough and smooth surfaces were exposed to 5 simulated rainfall applications at 5% and 20% slopes
. The results indicate that commonly held perceptions of the impact of soil surface roughness on runoff and erosion may not be entirely correct in all cases.
Scale relationships in hillslope runoff and erosion
Arizona ; Erosion ; Experimentation ; Grain size distribution ; Runoff ; Sediment budget ; Semi-arid area ; United States of America ; Watershed
Eight runoff plots, located within a small catchment within the Walnut Gulch Experimental Watershed, southern Arizona, were consructed to test the argument that sediment yield decreases as plot length increases. Runoff and sediment loss from
these plots were obtained for 10 natural storm events. Analysis of both runoff and sediment yield from the plots indicates that the relationship of sediment yield to plot length derives both from the limited travel distance of individual entrained particles
and from a decline in runoff coefficient as plot length increases.
Aggregate stability as an indicator of soil susceptibility to runoff and erosion; validation at several levels
The AA. aim to extend the validity of relationships between soil aggregation and erosion through comparisons of topsoil aggregate stability and field-assessed susceptibility to runoff and erosion. Susceptibility to runoff and erosion was determined
at 3 levels : first through measurements of runoff and soil loss from microplots (1 m2) under simulated rainfall in a southern French Regosol; second through 3-year measurements of runoff and soil loss on runoff plots (100-800 m2) in Benin, Cameroon
Incorporating soil surface crusting processes in an expert-based runoff model : sealing and transfer by runoff and erosion related to agricultural management
Agropedology ; Duricrust ; Field experiment ; France ; Haute-Normandie ; Infiltration ; Loess ; Model ; Precipitation ; Runoff ; Soil erosion ; Water erosion
The aim of this study was to contribute to the elaboration of an expert-based runoff prediction model able to simulate the influence of soil conservation practices in the context of loess soils susceptible to crusting. Experiments have been
is to describe the elaboration of the model called Sealing and Transfer by Runoff and Erosion related to Agricultural Management (STREAM)
Evaluating the MEFIDIS model for runoff and soil erosion prediction during rainfall events
Arizona ; Belgium ; Comparative study ; Model ; Precipitation ; Runoff ; Semi-arid area ; Soil erosion ; Temperate zone ; United States of America ; Water erosion
MEFIDIS (short for Physically Based Distributed Erosion Model) was developed to simulate the consequences of climate and land-use changes for surface runoff and erosion patterns during extreme rainfall events. The model relies on physically based
runoff and soil detachment equations, dividing the simulation area into spatial homogeneous units and using a dynamic approach for runoff and suspended sediment distribution. It was evaluated with measured runoff and net erosion data for 16 events
Spatial and temporal variation of runoff of Red River Basin in Yunnan
China ; Climatic change ; Climatic data ; Evaporation ; Geographical information system ; Mountain ; Precipitation ; Runoff ; Spatial variation ; Stream ; Temperature ; Valley ; Watershed ; Yunnan
This paper studies the variation of runoff of Red River Basin and discusses the influence of corridor-barrier functions of valleys and mountains on variation of runoff by using GIS and statistic methods based on the monthly precipitation
, temperature and evaporation data from 1960 to 2000 at 32 meteorological stations in Red River Basin, and the annual runoff data of Yuanjiang River, Lixian River and Panlong River from 1956 to 2000. These 3 river basins are contrasted. Results and discussion.
The trend on runoff variations in the Lhasa River Basin
China ; Climatic trend ; Multiple regression ; Precipitation ; Runoff ; Seasonal variation ; Temperature ; Tibet ; Watershed
Taking the Lhasa River Basin above Lhasa hydrological station in Tibetan Plateau as a study area, the characteristics of the annual and monthly mean runoff during 1956-2003 were analyzed, based on the hydro-data of the 2 hydrological stations (Lhasa
and Tanggya) and the meteorological data of the 3 meteorological stations (Damxung, Lhasa and Tanggya). The trends and the change points of runoff and climate from 1956 to 2003 were detected using the nonparametric Mann-Kendall test and Pettitt-Mann-Whitney
change-point statistics. The correlations between runoff and climate change were analyzed using multiple linear regression. Discussion of the results.
The effect of tillage-induced roughness on runoff and erosion patterns
A model, the Tillage-Controlled Runoff Pattern model (TCRP model) was developed to create a runoff pattern with flow in the direction of the plough-lines for all tilled fields within a catchment. The model needs a digital elevation model (DEM
), a landuse map and the major tillage orientation per tilled field as input. Runoff patterns created with the model could be used in any raster-based erosion model. The effect of the runoff pattern on simulated erosion patterns is shown for one field using
Runoff-induced sediment yield over dune slopes in the Negev Desert. 1 : quantity and variability
Data for arid dune slopes are scarce, owing to the widespread perception that the high infiltrability of sand will reduce runoff. However, runoff is generated on sandy dunes in the Hallamish dune field, western Negev Desert, due to the presence
of a thin microbiotic crust. The runoff in turn produces erosion. The goals of this study are to study the relationship between runoff and sediment yield; to study the variability of sediment production from the crest to the base of dune slopes; to compare
Hortonian runoff was measured in the laboratory from uniform slopes of lengths of 1.5, 3.0, and 6.0 m for steady, high-intensity rainstorms with durations of 1.0 to 7.5 min. A clear reduction in runoff per unit slope length was found as slope
lengths were increased. The runoff data were used to validate a simple process-based model that combines the Philip-two-term infiltration equation with the kinematic wave overland flow principle. The predicted and experimental results agreed well
The impact of vegetation changes on evaporation and runoff
Research context and methodology are considered for the determination of the impact of vegetation changes on evaporation and runoff. Most of the important advances in understanding of the problem since 1948, have resulted from combining
Volume and routing of late-glacial runoff from the southern Laurentide Ice Sheet
The major objective of this research was to quantify the outflow of meltwater and precipitation-generated runoff from the region that lay on and adjacent to the southern margin of the Laurentide Ice Sheet, during a major period of glacial melting
An examination of the efficiency of a simple runoff plot sample splitter
The study investigated the effect of flow rate, sediment concentration and sediment grain size on the efficiency of a simple runoff plot sample splitter. Results of the study showed that surface tension affects sampler efficiency at low flow rates
Runoff has been used as a variable representing climatic conditions. Relationships between runoff and sediment yield are shown in diagrams for different climatic groups. There is no universal statistically significant global correlation between
runoff and sediment yield which is valid for all climates. The global pattern in net erosion is shown in a separate map.
Drainage density as an index of the ratio of base flow to total runoff
The aim of this paper is not the estimation of applicability of drainage density for prediction of base flow volume, but only the estimation of the mean ratio of base flow to total runoff in its spatial differentiation.
The role of perimeter shape in estimating annual runoff from small Sierra Nevada basins
Perimeter shape of drainage basins is evaluated as a control of annual runoff depth from small Sierra Nevada basins underlain by granitic rocks. In contrast to three perimeter shape ratios, none of which contributes a statistical explanation
of annual runoff depth, three terms of a Fourier expansion of the basin perimeter substantially improve the estimating model.