Evaluation of Net-free Erosion Control Blankets
0
Citation
5
Reference
10
Related Paper
Abstract:
Erosion control blankets (ECBs) protect soil from being detached and transported by raindrops and subsequential overland runoff while assisting in vegetation growth. ECBs have several characteristics, for example, thickness, mass per unit area, tensile strength, elongation, water absorption, etc. However, the impact of these characteristics on the performance in mitigating erosion has yet to be well understood. To better understand the interactions of ECB properties with the detachment and transport of sediment, field tests were conducted at the Erosion Control Research and Training Center at the University of Illinois Urbana-Champaign. Various ECBs, including net-free ECBs and bionet ECBs, were tested on a 3H:1V hillslope under a 30-minute simulated rainfall event (2 in./hr). The soil used on the testing plot was silty clay loam. To investigate ECB effectiveness, total runoff volume, runoff start/end time, peak runoff rate, and sediment yield were monitored during each test. The results showed that water absorption played a big role in enhancing the performance of ECBs. The materials absorbed a large amount of water at the beginning and then acted as a wet film to cover the hillslope, reducing soil erosion by the overland flow when the soil was saturated. This wet film continued to reduce soil detachment, although it probably did not help with runoff reduction after saturation. Among the blankets tested, Profile F4 Netless was the most degradable and lightest one. North American Green DS75 had the most cost efficiency with $0.4 /sq. yd. There was no big difference in the installation method.Keywords:
Erosion Control
WEPP
WEPP
Water erosion
Cite
Citations (0)
Erosion Control
Cite
Citations (0)
ABSTRACT A fundamentally-based, soil erosion and sediment transport model which is incorporated with a distributed-system hydrologic model (ANSWERS) was developed. It is a single-event model and considers typical upland erosion and sedimentation processes of splash erosion, flow erosion, sediment transport, and deposition. Channel erosion is also included. Erosion rates are related to hydrologic and hydraulic variables; soil characteristics; and surface and geographic condi-tions. The model was tested with data from two small agricultural watersheds of less than 10 ha in area. The model simulated sediment discharges which were com-parable to observed data.
WEPP
Sedimentation
Deposition
Cite
Citations (32)
In different scale, the influence of the main factors on runoff,sediment yield and the composition of the main factors is not the same. According to the spatial scale,almost all of the soil erosion models can be classified as field-scale models,catchment-scale models and region-scale models.Each type of erosion models has its distinctive characteristics.As to the field scale,the analysis of the clear vertical zones and the interaction between them is very important.In addition to the analysis of soil erosion on hill slopes,effects of runoff and sediment from hill slope on erosion and sediment at the followed gully zone and the erosion caused by gravitation are complex and pivotal in the catchment scale. In this scale, the sediment delivery has a significant importance to the erosion modeling. Establishing region scale erosion model,the relationship and the interaction of the subordinate drainages together with the style of the runoff yield and runoff concentration should be taken into account.Commenting on the fitness and the existing problems of the popular erosion models home and abroad in these three scales,studying the experience of model building in the Yangdaogou watershed,a conceptual erosion model,as a intergradation model to the larger scale erosion model,is to be bring forward.
WEPP
Cite
Citations (0)
In the Water Erosion Prediction Project (WEPP) model, erosion and deposition are calculated based on apredefined value of sediment transport capacity (Tc), estimated from flow hydraulics, slope and sedimentproperties. Under this model concept, net erosion or deposition is estimated by the difference between sedimentload (qs) and Tc, i.e., erosion when qs < Tc and deposition when qs > Tc. Separate erosion and depositionequations are derived and an accurate assessment of erosion or deposition depends on how the Tc is estimated.Unfortunately, Tc is rarely measured experimentally, making it more a hypothetical concept rather than ameasurable quantity. Recent laboratory results from experiments conducted on a multiple-box system, underseepage and drainage conditions that changed soil erodibility for the same soil, challenged the Tc concept.Experimental observations suggest that erosion and deposition processes are occurring simultaneously anddifferent surface, flow and rainfall conditions may trigger the dominance of one process over the other.Therefore, we propose an alternative, single sediment mass balance equation, which contains both erosion anddeposition terms, to model sediment transport. As a first approximation, the erosion process is still modeled bya first-order rate process similar to the current WEPP erosion model, and the deposition process is estimated tobe proportional to qs. Separate rate constants are used for erosion and deposition processes. An analyticsolution for the proposed erosion equation is derived and the solution is examined for conditions similar to thelaboratory multiple box experiments. The analytic solution reproduced experimental data trends, in otherwords, it was able to simulate sediment mass balance scenarios ranging from deposition- to detachment- andtransport-dominated regimes. This proposed modification may lead to a better understanding of erosionprocesses, and consequently, an improved erosion prediction model.
WEPP
Deposition
Hydraulics
Cite
Citations (0)
This paper applies the WEPP model to simulate soil erosion and spatial variation in Sichuan hilly basin.The study was carried out on six cultivated slope lands and fifteen bare slope lands.As to single storm,the average relative error of six cultivated slope lands is 25.5%.The relative errors less than 30% account for 88.9% of all the errors of those six cultivated slope lands.The average error of fifteen bare slope lands is 20.3%,the relative errors less than 30% account for 86% of all the errors of those fifteen bare slope lands.The relative errors of annual soil erosion in 2004 and 2005 are 14.94% and 14.37%,respectively,which is less than those of single storms.So the WEPP model is more suitable to simulate soil erosion in long time scale.The WEPP model is also able to simulate the spatial variation of soil erosion.By means of sloping erosion curve,the erosion area can be divided into three parts: erosion developing part,erosion accelerating part and main erosion part.The length of erosion accelerating part has negative relation with rainfall and rainfall intensity,while the length of accelerating part and the erosion has positive relation with the length of slope.
WEPP
Cite
Citations (3)
Erosion following wildfire can be as much as 1000 times the erosion from an undisturbedforest. In August, 2005, the largest fire in the lower 48 states occurred in the Umatilla NationalForest in Southeast Washington. Researchers from the Rocky Mountain Research Station assistedthe forest in evaluating soil erosion risks using three different applications of the WEPP model.GeoWEPP was used to determine the onsite distribution of soil erosion. WEPP Windows WatershedVersion was used to estimate peak runoff rates of each of the 33 small watersheds analyzed, andthe ERMiT interface to WEPP was used to estimate the risk of erosion on selected hillslopes, and thebenefits of mulching those slopes. About 38 percent of the burned areas was analyzed within thethree days available for analysis. This paper summarizes the analytical methods, and the findings ofthe prediction runs.
WEPP
Water erosion
Cite
Citations (8)
This paper highlights past efforts in developing erosion process concepts that lead to the development of the current process-based erosion prediction model, i.e., WEPP. Recent progress includes the development of a multiple-box system that can simulate hillslope hydrologic conditions. Laboratory procedures enable the quantification of near-surface hydrologic effects, i.e.,artesian seepage vs. drainage, on the soil erosion process and sediment regime, flow hydraulics, and sediment transport and deposition processes. These recent findings improve soil erosion science and provide new erosion control strategies that may have additional environmental benefits relative to the traditional erosion control practices. The paper also discusses the potential impacts of the erosion process on erosion model development and future research directions of soil erosion process research and model development.
WEPP
Sediment control
Erosion Control
Deposition
Hydraulics
Cite
Citations (0)
This study was conducted to analyze field inspection results of erosion control facilities within national forests and to suggest maintenance and management plan of erosion control facilities. The objects amounted to a total of 1,628 locations, comprising 308 erosion control dams and 1,320 erosion control areas (1,269.05 ha). The field inspections were conducted during March-June each year. The erosion control dams inspected were constructed during 1991-2005, with 96.4% of them, or 297 dams, constructed in or after 2000. The erosion control areas were constructed during 1986-2005, with 68.6% of them, or 903 areas, constructed in or after 2000. As for erosion control dams, there were 205 concrete erosion control dams and 68 concrete with boulder pitching erosion control dams, respectively, with 296 out of a total of 308 erosion control dams in a good condition. As for erosion control areas, there were many erosion control structures using stone masonry works and gabions, with 1,245 out of a total of 1,320 (94.3%) erosion control areas in a good condition. Overall, erosion control facilities within national forests were in a good condition, amply fulfilling their functions. As for erosion control facilities in a bad condition, they must be made to accomplish the goals of erosion control works through supplementation and repairs without fail. In addition, for the systematic maintenance and management of existing erosion control facilities and erosion control facilities constructed in the future as part of erosion control works, the construction of an erosion control facility management system is urgently needed.
Erosion Control
Cite
Citations (1)
Erosion rates of recently graded nongravel forest roads were measured under rainfall simulation on five different soils. The erosion rates observed on 24 forest road erosion plots were compared with values predicted by the Water Erosion Prediction Project (WEPP) Model, Version 93.1. Hydraulic conductivity and soil erodibility values were predicted from methods developed for rangeland and cropland soils. It was found that on four of the five soils, runoff values were closely predicted and that the predicted erosion was not significantly different from the observed erosion when using rangeland methods for predicting soil erodibility. It was also found that interrill erosion rates were underpredicted using rangeland methods for predicting soil erodibility, but slightly overpredicted when using cropland interrill erodibility prediction methods. Rill erosion rates for road wheel ruts were closely predicted from rangeland rill erodibility algorithms.
WEPP
Rill
Forest road
Water erosion
Cite
Citations (25)