Erosion and Sediment Control At Road-Stream Crossings

1983 ◽  
Vol 59 (2) ◽  
pp. 62-66 ◽  
Author(s):  
R. L. Rothwell
Keyword(s):  
Suspended Sediment ◽  
Overland Flow ◽  
Bare Soil ◽  
High Variability ◽  
Final Conclusion ◽  
Sediment Control ◽  
Sediment Production ◽  
Control Erosion

The effectiveness of a "brush mulch" to control erosion and sediment at road-stream crossings was evaluated by measurement and comparison of upstream and downstream suspended sediment. The brush mulch consisted of logging debris, such as branches, tree tops and logs 2-15 cm in diameter, laid on the ground to intercept and to slow overland flow and to trap sediment. Two treatments were defined and tested. Treatment no. 1 was a brush mulch and grass-fertilizer mixture applied by hydroseeding to three bare soil road-stream crossings. Treatment no. 2 was a grass-fertilizer mixture applied by hydroseeding to another three road-stream crossings.Total seasonal and storm sediment production for mulched and unmulched crossings averaged 31 and 37, and 566 and 2297 kg/day/ha, respectively. Tests showed significant differences between treatments for both seasonal and storm sediment production. The levels of significance were low because of high variability in sediment production among treatments and road crossings. Frequent onsite inspections during storm and nonstorm conditions, however, identified sources of variability and supported a final conclusion that the brush mulch was effective for erosion and sediment control at road-stream crossings.

scholarly journals Modelling impacts of spatially variable erosion drivers on suspended sediment dynamics

2020 ◽  
Vol 8 (3) ◽  
pp. 619-635 ◽  
Author(s):  
Giulia Battista ◽  
Peter Molnar ◽  
Paolo Burlando
Keyword(s):  
Spatial Variability ◽  
Suspended Sediment ◽  
Overland Flow ◽  
Sediment Dynamics ◽  
Suspended Sediment Transport ◽  
Delivery Ratio ◽  
Sediment Production ◽  
Variable Surface ◽  
Spatially Distributed ◽  
The Impact

Abstract. Suspended sediment load in rivers is highly uncertain because sediment production and transport at catchment scale are strongly variable in space and time, and they are affected by catchment hydrology, topography, and land cover. Among the main sources of this variability are the spatially distributed nature of overland flow as an erosion driver and of surface erodibility given by soil type and vegetation cover distribution. Temporal variability mainly results from the time sequence of rainfall intensity during storms and snowmelt leading to soil saturation and overland flow. We present a new spatially distributed soil erosion and suspended sediment transport module integrated into the computationally efficient physically based hydrological model TOPKAPI-ETH, with which we investigate the effects of the two erosion drivers – precipitation and surface erodibility – on catchment sediment fluxes in a typical pre-Alpine mesoscale catchment. By conducting a series of numerical experiments, we quantify the impact of spatial variability in the two key erosion drivers on erosion–deposition patterns, sediment delivery ratio, and catchment sediment yields. Main findings are that the spatial variability in erosion drivers affects sediment yield by (i) increasing sediment production due to a spatially variable precipitation, while decreasing it due to a spatially variable surface erodibility, (ii) favouring the clustering of sediment source areas in space by surface runoff generation, and (iii) decreasing their connectivity to the river network by magnifying sediment buffers. The results highlight the importance of resolving spatial gradients controlling hydrology and sediment processes when modelling sediment dynamics at the mesoscale, in order to capture the key effects of sediment sources, buffers, and hillslope hydrological pathways in determining the sediment signal.

The effect of rainfall intensity on soil erosion and particulate phosphorus transfer from arable soils

1999 ◽  
Vol 39 (12) ◽  
pp. 41-45 ◽  
Author(s):  
A. I. Fraser ◽  
T. R. Harrod ◽  
P. M. Haygarth
Keyword(s):  
Soil Erosion ◽  
Suspended Sediment ◽  
Rainfall Intensity ◽  
Overland Flow ◽  
Agricultural Soils ◽  
Arable Land ◽  
Significant Proportion ◽  
Particulate Phosphorus ◽  
Arable Soils ◽  
Flow Monitoring

Soil erosion, in the form of transported suspended sediment in overland flow, is often associated with high rates of particulate phosphorus (PP) (total P>0.45 μm) transfer from land to watercourses. Particulate P may provide a long-term source of P for aquatic biota. Twenty-two sites for winter overland flow monitoring were selected in south-west England within fields ranging from 0.2–3.8 ha on conventionally-managed arable land. Fields were situated on highly porous, light textured soils, lacking impermeable horizons and often overlying major aquifers. Long arable use and modern cultivation methods result in these soils capping under rain impact. Overland flow was observed when rainfall intensity approached the modest rate of 0.8 mm hr−1 on land at or near to field capacity. Low intensity rainfall (<2 mm hr−1) produced mean suspended sediment losses of 14 kg ha−1 hr−1, with associated PP transfer rates of 16 g ha−1 hr−1. In high intensity rainfall (>9 mm hr−1) mean PP losses of 319 g ha−1 hr−1 leaving the field were observed. As might be expected, there was a good relationship between PP and suspended sediment transfer in overland flow leaving the sites. The capacity of light soils to cap when in arable use, combined with heavy or prolonged rainfall, resulted in substantial discharges, soil erosion and associated PP transfer. Storms with heavy rain, typically of only a few hours duration, were characterised by considerable losses of PP. Such events, with return periods of once or twice a winter, may account for a significant proportion of total annual P transfer from agricultural soils under arable crops. However, contributions from less intense rain with much longer duration (around 100 hours per winter in many arable districts of the UK) are also demonstrated here.

scholarly journals Comparison of sediment rating curves and sediment yield in subbasins of the Itacaiúnas River Watershed, Eastern Amazon

RBRH ◽  
2021 ◽  
Vol 26 ◽  
Author(s):  
Marcio Sousa da Silva ◽  
Rosane Lopes Cavalcante ◽  
Pedro Walfir Martins e Souza Filho ◽  
Renato Oliveira da Silva Júnior ◽  
Paulo Rógenes Pontes ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Sediment Yield ◽  
High Water ◽  
Water Levels ◽  
Tropical Rivers ◽  
River Watershed ◽  
Sediment Production ◽  
Power Equation ◽  
Suspended Sediment Concentrations ◽  
Rating Curves

ABSTRACT Understanding the hydrosedimentological dynamics of tropical rivers is a challenge in the Amazon due to its remote and difficult-to-access areas. This study was based on data collected from 16 hydrosedimentological control sections in the 6 subbasins that make up the Itacaiúnas River Watershed (IRW), with 4 annual campaigns (high water levels, rising water levels, falling water levels, low water levels) between 2015 and 2019, with the aim of constructing and comparing sediment rating curves and sediment yield. The data at the mouth of the IRW revealed that the rainy season is responsible for 93% of liquid discharges (Q) with an average of 1460.88 m3/s and for 98% of suspended sediment discharges (SSQ) with an average of 5864.15 tons/day. Suspended sediment concentrations (SSCs) are low to moderate (50 to 150 mg/l). The curves encompassing all the data showed R2 values (0.92 to 0.99) greater than the curves with only the values of the rainy or dry season, indicating a good fit of the power equation to the SSQ and Q data for all sections studied. Higher values of coefficients a and b show areas of greater sediment production and deforestation, as well as areas with new sources of sediment and preserved forest.

scholarly journals Modelling Runoff and Sediment Loads in a Developing Coastal Watershed of the US-Mexico Border

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1024 ◽  
Author(s):  
Napoleon Gudino-Elizondo ◽  
Trent W. Biggs ◽  
Ronald L. Bingner ◽  
Eddy J. Langendoen ◽  
Thomas Kretzschmar ◽  
...  
Keyword(s):  
Sediment Load ◽  
Field Measurements ◽  
Control Measures ◽  
Storm Event ◽  
Sediment Control ◽  
Coastal Watershed ◽  
Sediment Production ◽  
Sediment Loads ◽  
Northwestern Mexico ◽  
Mean Square Errors

Urbanization can increase sheet, rill, gully, and channel erosion. We quantified the sediment budget of the Los Laureles Canyon watershed (LLCW), which is a mixed rural-urbanizing catchment in Northwestern Mexico, using the AnnAGNPS model and field measurements of channel geometry. The model was calibrated with five years of observed runoff and sediment loads and used to evaluate sediment reduction under a mitigation scenario involving paving roads in hotspots of erosion. Calibrated runoff and sediment load had a mean-percent-bias of 28.4 and − 8.1, and root-mean-square errors of 85% and 41% of the mean, respectively. Suspended sediment concentration (SSC) collected at different locations during one storm-event correlated with modeled SSC at those locations, which suggests that the model represented spatial variation in sediment production. Simulated gully erosion represents 16%–37% of hillslope sediment production, and 50% of the hillslope sediment load is produced by only 23% of the watershed area. The model identifies priority locations for sediment control measures, and can be used to identify tradeoffs between sediment control and runoff production. Paving roads in priority areas would reduce total sediment yield by 30%, but may increase peak discharge moderately (1.6%–21%) at the outlet.

Diffused and localized sediment production processes in a distributed transport model

2020 ◽  
Author(s):  
Giulia Battista ◽  
Peter Molnar ◽  
Fritz Schlunegger ◽  
Paolo Burlando
Keyword(s):  
Surface Roughness ◽  
High Resolution ◽  
Overland Flow ◽  
Sediment Load ◽  
Transport Model ◽  
Sediment Sources ◽  
Local Surface ◽  
Sediment Production ◽  
Production Processes ◽  
Spatially Distributed

<p>The identification of preferential sediment production areas within a river basin is essential to improve predictions of sediment load and its sources, and to identify sources of potential water pollution. The role of these localized sediment sources is especially relevant in the sediment budget of alpine basins, where erosion in highly non-uniform and mass movements play a major role in the mobilization of sediments. While sediment tracers are useful to assess the origin of river-borne sediments, currently very few spatially distributed sediment transport models include the sediment production from a variety of sources and track sediment from source to outlet.</p><p>In this work, we present a new approach to include the production of sediment from localized sources, in addition to diffusive overland flow erosion, in a spatially distributed sediment production and transport model. This extension of the hydrological model Topkapi-ETH simulates the mobilization of sediments by (i) overland flow erosion, (ii) sediment pickup from landsliding areas by overland flow and (iii) river discharge, and (iv) sediment pickup from deeply incised valleys by channel flow. Landslides and incised valleys were identified from geological/geomorphological maps and a high resolution DEM of the study basin. To model the contribution of landslides, we introduce a parameter λ for gully competence, which describes the effectiveness of overland flow in mobilizing the sediments. Overall, λ affects the contributions of the different sediment production processes to the modelled sediment load at the basin outlet. To estimate a value of λ for the case study, we propose the local surface roughness to quantify the gully development onto the landslide surfaces. Additionally, we use available <sup>10</sup>Be measurements across the basin to assign a concentration to each sediment production process and select the end member value of λ that best reproduces the observed <sup>10</sup>Be concentrations at the outlet.</p><p>Our simulations indicate that including the production of sediments from localized sources with processes (ii) to (iv) is essential to capture the highest observed concentrations with the model. Moreover, the same observed suspended sediment concentrations at the outlet may be obtained with different combinations of sediment production processes in function of the gully competence. Finally, the local surface roughness analysis and the use of <sup>10</sup>Be concentration as a sediment tracer suggest that channel processes are dominant over hillslope sediment production in the study basin.</p><p>In conclusion, our work shows that combinations of physically-based sediment transport modelling with geomorphological mapping of localized sediment sources, high-resolution topographic information and point measurements of cosmogenic radionuclide concentrations allow to infer the dominant sediment production processes in river basins.</p>

Hillslope runoff and erosion on duplex soils in grazing lands in semi-arid central Queensland. II. Simple models for suspended and bedload sediment

Soil Research ◽  
2011 ◽  
Vol 49 (2) ◽  
pp. 118 ◽  
Author(s):  
D. M. Silburn
Keyword(s):  
Suspended Sediment ◽  
Sediment Concentration ◽  
Bare Soil ◽  
Measured Parameter ◽  
Cover Factor ◽  
Bedload Sediment ◽  
Grazing Lands ◽  
Parameter Values ◽  
Soil Losses ◽  
Simple Models

The use of simple models of soil erosion which represent the main effects of management in grazing lands in northern Australia is limited by a lack of measured parameter values. In particular, parameters are needed for erosion models (sediment concentration v. cover equations) used in daily soil-water balance models. For this research, we specifically avoided equations that use rainfall and runoff rates (e.g. peak flow), as current daily models are limited in their ability to estimate these rates. The resulting models will therefore give poor estimates of soil losses for individual events, but should give good estimates of long-term average erosion and management influences. Runoff and erosion data were available for 7 years on 12 hillslope plots with cover of 10–80%, with and without grazing, with and without tree canopy cover, on a variety of soils according to various soil classification systems. Soils were grouped into those derived from sandstone (SS), mudstone (MS), and eroded mudstone (MSe). These data were used to determine two parameters, i.e. (i) efficiency of entrainment for bare soil and (ii) a cover factor, for simple models of bedload and suspended sediment concentrations. Methods used to fit parameters affected the results; optimising to obtain the minimum sum of squares of errors in soil losses gave better results than fitting an exponential equation to sediment concentration–cover data. The use of a linear slope factor in the sediment concentration models was confirmed with data from plots with slopes 4–8%. Parameters for the bedload sediment concentration model were the same for SS, MS, and MSe soils. Parameters for the suspended sediment concentration model were the same for SS and MS soils, but the MSe soil had a greater efficiency of entrainment for bare soil (about double). The sediment concentration–cover relationships and fitted cover factors were different for suspended and bedload sediment. Thus, the resulting modelled proportion of sediment as suspended load changed with cover, from ~0.3 for bare soil to 0.9 at 80% cover, mimicking the measured data. The cover factor was lower than published values for cultivated soils, indicating less reduction in sediment concentration with greater cover. A compilation of parameter values for the sediment concentration model from published and unpublished sources in grazing and cropping lands is provided.

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.

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