scholarly journals Experimental Study of Freeze-Thaw/Water Compound Erosion and Hydraulic Conditions as Affected by Thawed Depth on Loessal Slope

2020 ◽  
Vol 8 ◽  
Author(s):  
Wei Wang ◽  
Zhanbin Li ◽  
Rui Yang ◽  
Tian Wang ◽  
Peng Li
Keyword(s):  
Soil Loss ◽  
Loss Rate ◽  
Rainfall Intensity ◽  
Freeze Thaw ◽  
Erosion Processes ◽  
Hydraulic Conditions ◽  
The Mean ◽  
The Relationship ◽  
Thaw Water ◽  
Soil Loss Rate

Freeze-thaw cycles have significant influences on slope erosion processes. In this study, simulated rainfall laboratory experiments were implemented to investigate erosion processes and the relationship between the soil loss rate and hydraulics conditions under different thawed depths and rainfall intensities. The results indicated that linear regression could be used to describe the relationship between the soil loss rate and runoff time. Soil loss rate, as measured by the curve slope k (represented the increase rate in the soil loss rate), generally increased with runoff time over different thawed depths across all rainfall intensities. The k values generally increased with rainfall intensity from 0.6 to 1.2 mm/min, with the exception of the 4 cm thawed slope, for which the k values initially increased before decreasing with rainfall intensity from 0.6 to 1.2 mm/min. The mean soil loss rate and range also increased with thawed depth under the same rainfall intensity. Finally, the interaction of rainfall intensity and thawed depth had the greatest effect on soil loss rate, while stream erosion power was the hydraulic parameter that exhibited the best soil loss rate prediction performance. The results presented herein improve the understanding of the response of freeze-thaw/water compound erosion to hydraulic conditions.

MUSLE Evaluation of Soil Loss on a Construction Site by Using Gauging Weirs

2012 ◽  
Vol 446-449 ◽  
pp. 2718-2721 ◽  
Author(s):  
Siti Isma Hani Ismail ◽  
Hooi Min Yee
Keyword(s):  
Soil Loss ◽  
Loss Rate ◽  
Rainfall Intensity ◽  
Empirical Modeling ◽  
Storm Event ◽  
Construction Site ◽  
Construction Sites ◽  
Impervious Cover ◽  
Storm Rainfall ◽  
Soil Loss Rate

During urbanization, large areas of soil are exposed to the risk of soil erosion due to extensive earthworks and construction activities. Runoff from construction sites is known by far the largest source of sediment clogging our waterways. Erosion occurred from the study area due to removal of vegetation, high rainfall intensity, alteration of existing topography, and the covering of previously vegetated surfaces with impervious cover such as roads, driveways and buildings. The main objective of this study is to evaluate the soil loss due to storm rainfall and runoff on a construction site located at Sungai Ara, Penang State of Malaysia. A purpose-built hydraulic structure namely Sharp Crested Rectangular Weir was constructed and installed on site for more reliable estimates of flow during storms. The soil loss was then evaluated by using an empirical modeling known as the Modified Universal Soil Loss Equation (MUSLE). Results showed that large amount of sediment has being eroded from the study area during these activities. The highest soil loss rate was estimated was 64 ton/ha during a storm event.

Estimating soil loss from changes in soil cesium-137

1993 ◽  
Vol 73 (4) ◽  
pp. 629-632 ◽  
Author(s):  
R. Gary Kachanoski
Keyword(s):  
Key Words ◽  
Power Function ◽  
Soil Loss ◽  
Erosion Rate ◽  
Loss Rate ◽  
Cesium 137 ◽  
Complicated Model ◽  
Simple Power Function ◽  
The Relationship ◽  
Soil Loss Rate

A simple power-function equation was developed to relate changes in soil 137Cs with time to an average annual soil-loss rate. The equation accounts for tillage dilution of the concentration of 137Cs in the surface plow layer and for enrichment in the eroding soil. The predictions from the relationship were similar to values for a more complicated model and to measured values given in previous studies. Key words: Erosion rate, prediction, cesium-137

scholarly journals Identifying erosive periods by using RUSLE factors in mountain fields of the Central Spanish Pyrenees

2008 ◽  
Vol 12 (2) ◽  
pp. 523-535 ◽  
Author(s):  
M. López-Vicente ◽  
A. Navas ◽  
J. Machín
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Loss ◽  
Rainfall Intensity ◽  
Soil Moisture Content ◽  
Rainfall Erosivity ◽  
Soil Erodibility ◽  
Maximum Rainfall ◽  
Freeze Thaw ◽  
Soil Losses

Abstract. The Mediterranean environment is characterized by strong temporal variations in rainfall volume and intensity, soil moisture and vegetation cover along the year. These factors play a key role on soil erosion. The aim of this work is to identify different erosive periods in function of the temporal changes in rainfall and runoff characteristics (erosivity, maximum intensity and number of erosive events), soil properties (soil erodibility in relation to freeze-thaw processes and soil moisture content) and current tillage practices in a set of agricultural fields in a mountainous area of the Central Pyrenees in NE Spain. To this purpose the rainfall and runoff erosivity (R), the soil erodibility (K) and the cover-management (C) factors of the empirical RUSLE soil loss model were used. The R, K and C factors were calculated at monthly scale. The first erosive period extends from July to October and presents the highest values of erosivity (87.8 MJ mm ha−1 h−1), maximum rainfall intensity (22.3 mm h−1) and monthly soil erosion (0.25 Mg ha−1 month−1) with the minimum values of duration of erosive storms, freeze-thaw cycles, soil moisture content and soil erodibility (0.007 Mg h MJ−1 mm−1). This period includes the harvesting and the plowing tillage practices. The second erosive period has a duration of two months, from May to June, and presents the lowest total and monthly soil losses (0.10 Mg ha−1 month−1) that correspond to the maximum protection of the soil by the crop-cover ($C$ factor = 0.05) due to the maximum stage of the growing season and intermediate values of rainfall and runoff erosivity, maximum rainfall intensity and soil erodibility. The third erosive period extends from November to April and has the minimum values of rainfall erosivity (17.5 MJ mm ha−1 h−1) and maximum rainfall intensity (6.0 mm h−1) with the highest number of freeze-thaw cycles, soil moisture content and soil erodibility (0.021 Mg h MJ−1 mm−1) that explain the high value of monthly soil loss (0.24 Mg ha−1 month−1). The interactions between the rainfall erosivity, soil erodibility, and cover-management factors explain the similar predicted soil losses for the first and the third erosive periods in spite of the strong temporal differences in the values of the three RUSLE factors. The estimated value of annual soil loss with the RUSLE model (3.34 Mg ha−1 yr−1) was lower than the measured value with 137Cs (5.38 Mg ha−1 yr−1) due to the low values of precipitation recorded during the studied period. To optimize agricultural practices and to promote sustainable strategies for the preservation of fragile Mediterranean agrosystems it is necessary to delay plowing till October, especially in dryland agriculture regions. Thus, the protective role of the crop residues will extend until September when the greatest rainfall occurs together with the highest runoff erosivity and soil losses.

scholarly journals Agricultural Expansion in the Brazilian Cerrado: Increased Soil and Nutrient Losses and Decreased Agricultural Productivity

Land ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 12 ◽  
Author(s):  
Luciene Gomes ◽  
Silvio Simões ◽  
Eloi Dalla Nora ◽  
Eráclito de Sousa-Neto ◽  
Maria Forti ◽  
...  
Keyword(s):  
Soil Loss ◽  
Loss Rate ◽  
Productivity Loss ◽  
Agricultural Productivity ◽  
Sustainable Use ◽  
Nutrient Loss ◽  
Geographical Information ◽  
Agricultural Expansion ◽  
Brazilian Cerrado ◽  
Soil Loss Rate

While food and nutrition security are issues that national and international organizations are tackling, one of the central problems often overlooked is the essential role of soils in providing nutritious food. Soils are the base for food production and food security. However, the majority of soils are in fair and poor conditions, with the most significant threats being erosion and loss of nutrients. In this study, we estimate the potential of soil loss, agricultural productivity loss, and nutrient loss for Brazil’s most important agricultural region, the Brazilian Cerrado, for the years 2000 and 2012. For this, we applied the Revised Universal Soil Loss Equation (RUSLE) model integrated with a geographical information system (GIS) to estimate annual soil loss rate and agricultural productivity loss, and used total nitrogen and total phosphorus in soil to estimate the annual nutrient loss rate caused by soil loss. All model factors and data were obtained from the literature. The results show that agricultural expansion in the Brazilian Cerrado is increasing the area of severe erosion, occasioning agricultural productivity decrease and soil nutrient depletion. The annual soil loss rate increased from 10.4 (2000) to 12.0 Mg ha−1 yr−1 (2012). Agricultural productivity loss occurred in more than 3 million hectares of crops and silviculture in 2000 and in more than 5.5 million hectares in 2012. Severely eroded areas lost between 13.1 and 25.9 times more nutrients than areas with low and moderate soil loss rates. These findings show that government policy should be directed to ensure the sustainable use of soils, mainly in agriculturally consolidated regions of the Brazilian Cerrado.

Application of Erosion 2D Model for Erosion Studies in Makurdi Metropolis of Benue State, Nigeria

2011 ◽  
Vol 367 ◽  
pp. 815-825 ◽  
Author(s):  
M.O. Isikwue ◽  
T.G. Amile
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Loss Rate ◽  
Physically Based Model ◽  
Cover Cropping ◽  
Physically Based ◽  
The City ◽  
Land Grading ◽  
2D Model ◽  
Soil Loss Rate

The equations of Erosion 2D Model (a physically based model) were transformed into a computer programme called EROSOFT and used to predict the rate of soil loss in Makurdi metropolis. The model has detachment, transport and deposition components. Four sites were chosen within the metropolis for this study. Soil samples were collected from the sites for laboratory analysis. Rainfall and runoff fluids were collected from the sites to determine their densities. Levelling instrument was used to detremine the channels slopes. The model predicted an average annual soil loss rate of 310kg m-2s-1 for the metropolis. The sensitivity analysis of the model indicates that straight slopes are more prone to soil erosion. The result of the model deviates slightly from established facts that, sandy soils are more erodible and hence prone to be easily detached. Nevertheless, the model shows that soil erosion is influenced by slope geometry and rainfall intensity. The study attributes the major causes of soil erosion in the city to urban runoff concentration and removal of vegetation, and therefore suggests the use of land grading, land forming and cover cropping as well as conservation structures like road side drains for the control of erosion in the metropolis.

scholarly journals A study on soil loss rate assessment of vegetation mat measures

2016 ◽  
Vol 10 ◽  
pp. 21-31 ◽  
Author(s):  
Eun Jin Han ◽  
Yong Sung Park ◽  
Young Do Kim ◽  
Jae Hyeon Park
Keyword(s):  
Soil Loss ◽  
Loss Rate ◽  
Soil Loss Rate

GIS estimation of annual average soil loss rate from Hangar River watershed using RUSLE

2019 ◽  
Vol 11 (2) ◽  
pp. 529-539 ◽  
Author(s):  
Mahmud Mustefa ◽  
Fekadu Fufa ◽  
Wakjira Takala
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Loss Rate ◽  
Study Finding ◽  
Mitigation Measures ◽  
Rainfall Erosivity ◽  
Vegetative Cover ◽  
Annual Average ◽  
Slope Length ◽  
Soil Loss Rate

Abstract Currently, soil erosion is the major environmental problem in the Blue Nile, Hangar watershed in particular. This study aimed to estimate the spatially distributed mean annual soil erosion and map the most vulnerable areas in Hangar watershed using the revised universal soil loss equation. In this model, rainfall erosivity (R-factor), soil erodibility (K-factor), slope steepness and slope length (LS-factor), vegetative cover (C-factor), and conservation practice (P-factor) were considered as the influencing factors. Maps of these factors were generated and integrated in ArcGIS and then the annual average soil erosion rate was determined. The result of the analysis showed that the amount of soil loss from the study area ranges from 1 to 500 tha−1 yr−1 with an average annual soil loss rate of 32 tha−1 yr−1. Considering contour ploughing with terracing as a fully developed watershed management, the resulting soil loss rate was reduced from 32 to 19.2 tha−1 yr−1. Hence, applying contour ploughing with terracing effectively reduces the vulnerability of the watershed by 40%. Based on the spatial vulnerability of the watershed, most critical soil erosion areas were situated in the steepest part of the watershed. The result of the study finding is helpful for stakeholders to take appropriate mitigation measures.

Quantitative Evaluation of the Relationship Between Slope Gradient and Infiltration Capacity Based on a Rainfall Experiment Using Pit Sand

2020 ◽  
Vol 15 (6) ◽  
pp. 745-753
Author(s):  
Toru Danjo ◽  
◽  
Tomohiro Ishizawa
Keyword(s):  
Surface Layer ◽  
Slope Stability ◽  
Soil Loss ◽  
Rainfall Intensity ◽  
Horizontal Distance ◽  
Slope Gradient ◽  
Slope Surface ◽  
Infiltration Capacity ◽  
Tank Model ◽  
The Relationship

The infiltration of rainfall into a slope surface may affect slope stability; thus, it is important to understand the amount of rainfall infiltration (hereafter referred to as the “infiltration capacity”) for a slope surface layer when evaluating slope stability. This research focuses on slope gradient, a factor affecting the infiltration capacity, and performs two types of water-spraying experiments using pit sand under the same conditions but with different slope gradients. In the first experiment, the surface flow rate and soil loss were measured using an earth-tank model with a horizontal distance of 0.5 m, depth of 0.1 m, and width of 0.2 m to form slope gradients of 2°, 20°, and 40° to clarify the effect of slope gradient on the infiltration capacity. In the second experiment, a water-spraying experiment that closely simulated natural rainfall was performed at a large-scale rainfall facility owned by the National Research Institute for Earth Science and Disaster Resilience (NIED), Japan. This experiment used an earth-tank model with a horizontal distance of 1.21 m, depth of 0.5 m, and width of 0.5 m to form slope gradients of 2°, 10°, 20°, 30°, and 40° with the aim of proposing a quantitative evaluation method for the relationship between the slope gradient and infiltration capacity. The results showed that the soil loss and infiltration capacity increased as the slope gradient increased in the case of the pit sand used in the experiments. This was confirmed to be due to the fact that an increased gradient allowed grains with diameters of <50 μm in the slope surface layer to flow out easily, thereby increasing the infiltration capacity. In addition, the relationship between the rainfall intensity and infiltration capacity revealed that the infiltration capacity varied depending on the rainfall intensity and slope gradient, which is unlike the relationship for constant values such as the permeability coefficient. Moreover, the research findings indicated a strong, positive linear relationship (R2 = 0.98) between the slope gradient and fitting factor Ic. Therefore, the relationship between rainfall intensity and the infiltration capacity could be expressed using the fitting factor Ic. This suggests the possibility of quantitatively evaluating the relationships between rainfall intensity, the infiltration slope gradient, and the infiltration capacity.

scholarly journals Assessment of Soil Loss Rates in Asreh Watershed (North Jordan Badia) Using RUSLE and GIS

2021 ◽  
Vol 12 (1) ◽  
pp. 10-16
Author(s):  
Saad M. AlAyyash ◽  
Keyword(s):  
Soil Loss ◽  
Loss Rate ◽  
Rainwater Harvesting ◽  
Annual Rainfall ◽  
Physical Factors ◽  
Rainfall Erosivity ◽  
Water Harvesting ◽  
Rainfall Runoff ◽  
Semi Arid ◽  
Soil Loss Rate

In arid lands, rainwater harvesting can play an important role in making more water available since most of the rainfall runoff evaporates. If rainwater can be collected, it will form a useful resource. Jordan is classified as one of the poorest countries regarding water resources with an arid and semi-arid climate. For these limited and vital sources of water, good estimation of rainfall runoff quantity and quality can enhance the sustainability of water harvesting projects. The hydrologic estimations of runoff quantities and qualities are essential, and several techniques to achieve that exist. Revised Universal Soil Loss Equation (RUSLE) is one of the widely used techniques to assess the soil erosion due to runoff, by assessing other physical factors that affect the soil loss. RUSLE combined five parameters to identify the soil loss rate: rainfall erosivity, topographic, soil erodibility, vegetation cover and management, and land management. Based on RUSLE results, areas are classified as a highly soil loss rate if the annual rates exceeded 20 tons per hectare. The Asreh watershed is a 196 km2 area that is mostly wasted land and receives an annual rainfall between 50 and 300 mm per year. The RUSLE equation inputs parameters for the study area are found and the equation is applied for the watershed. Results of RUSLE application on the Asreh watershed showed that the average annual soil loss rate is about 7.8 tons per hectare, about 73% of the area are classified as low soil loss rate with less than 10 tons per hectare per year, and only 13% of the area is classified as a high soil loss rate of more than 20 tons per hectare per year.

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