scholarly journals Assessment of Erosion Characteristics in Purple and Yellow Soils Using Simulated Rainfall Experiments

2021 ◽  
Vol 19 (1) ◽  
pp. 357
Author(s):  
Banglin Luo ◽  
Zhen Han ◽  
Jing Yang ◽  
Qing Wang
Keyword(s):  
Soil Erosion ◽  
Fine Particles ◽  
Sediment Concentration ◽  
Three Gorges Reservoir Area ◽  
Purple Soil ◽  
Slope Gradient ◽  
Rainfall Events ◽  
Erosion Processes ◽  
Steady Rate ◽  
Slope Factor

Soil erosion of sloped lands is one of the important sources of substantive sediments in watersheds. In order to investigate erosion characteristics of sloped lands during rainfall events in the Three Gorges Reservoir Area, erosion processes of purple and yellow soils under different slope gradients and rainfall intensities were studied by using a rainfall simulator. The results showed that the sediment concentration in runoff was closely correlated with rainfall intensity. The sediment concentration in runoff gradually rose to a peak with time, and then gradually declined and approach a steady rate during simulation rainfall events. The particle size distribution of surface soils before the rainfall was different from that after the rainfall. Soil erosion mainly resulted in the loss of fine particles of surface soil through runoff, and the fine particles of soil were enriched in sediments. Soil erosion rates were gradually increased with the slope gradient when the slope gradient was less than 10°, and significantly increased when the slope gradient was more than 10°. The slope factor of yellow soil could be fitted well to that calculated by the formula of Universal Soil Loss Equation (USLE). The trend of the slope factor of purple soil was similar to that of the slope factor that was derived from USLE. Therefore, the effect of slope gradients on soil erosion need to be further researched when USLE was applied to predict erosion in purple soil area.

scholarly journals Impact of Wheat Residue on Soil Erosion Processes

2018 ◽  
Vol 46 (2) ◽  
pp. 553-562 ◽  
Author(s):  
Ataollah KAVIAN ◽  
Leila GHOLAMI ◽  
Maziar MOHAMMADI ◽  
Velibor SPALEVIC ◽  
Moghadeseh FALAH SORAKI
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
Soil Conservation ◽  
Rainfall Intensity ◽  
Sandy Loam ◽  
Sediment Concentration ◽  
Runoff Coefficient ◽  
Northern Iran ◽  
Erosion Processes ◽  
Loam Soil

Soil erosion is one of the key challenges in soil and water conservation. Vegetation that covers soil and organic and inorganic mulch is very useful for the control of erosion processes. This study examined treatment with wheat residual (as agriculture mulch) on infiltration, time to runoff, runoff coefficient, sediment concentration and soil erosion processes. The study has been conducted for sandy-loam soil taken from summer rangeland (Northern Iran) with simulated rainfall intensities of 50 and 100 mm h-1. The experiment was conducted in slopes of 30% in three replications with two amounts of wheat residual of 50 and 90 %. The results showed that conservation percent of soil erosion for wheat residual 50 and 90% was 61.68 and 73.25%, respectively (in rainfall intensity of 50 mm h-1). Also, the conservation percent of soil erosion for wheat residual of 50 and 90% cover was 70.68 and 90.55, respectively (in rainfall intensity of 100 mm h-1). It was concluded that the conservation treatments could reduce runoff coefficient, sediment concentration and soil erosion and increase the time to runoff and infiltration coefficient. This effect was significant on time for infiltration, sediment concentration and soil erosion variables (R2=0.99), time to runoff and runoff coefficient variables (R2=0.95). The interaction effects of rainfall intensity and soil conservation was significant for sediment concentration and soil erosion variables (R2=0.99).

scholarly journals Hydraulic characteristics and sediment generation on slope erosion in the Three Gorges Reservoir Area, China

2016 ◽  
Vol 64 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Feng Qian ◽  
Dongbin Cheng ◽  
Wenfeng Ding ◽  
Jiesheng Huang ◽  
Jingjun Liu
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Rainfall Intensity ◽  
Purple Soil ◽  
Three Gorges ◽  
Slope Gradient ◽  
Stream Power ◽  
Yield Rate ◽  
The Three Gorges ◽  
Subsurface Runoff

Abstract Hydrological processes play important roles in soil erosion processes of the hillslopes. This study was conducted to investigate the hydrological processes and the associated erosional responses on the purple soil slope. Based on a comprehensive survey of the Wangjiaqiao watershed in the Three Gorges Reservoir, four typical slope gradients (5°, 10°, 15°and 20°) were applied to five rainfall intensities (0.6, 1.1, 1.61, 2.12 and 2.54 mm·min-1). The results showed that both surface and subsurface runoff varied greatly depending on the rainfall intensity and slope gradient. Surface runoff volume was 48.1 to 280.1 times of that for subsurface runoff. The critical slope gradient was about 10°. The sediment yield rate increased with increases in both rainfall intensity and slope gradient, while the effect of rainfall intensity on the sediment yield rate was greater than slope gradient. There was a good linear relationship between sediment yield rate and Reynolds numbers, flow velocity and stream power, while Froude numbers, Darcy-Weisbach and Manning friction coefficients were not good hydraulic indicators of the sediment yield rate of purple soil erosion. Among the three good indicators (Re, v and w), stream power was the best predictor of sediment yield rate (R2 = 0.884). Finally, based on the power regression relationship between sediment yield rate, runoff rate, slope gradient and rainfall intensity, an erosion model was proposed to predict the purple soil erosion (R2 = 0.897). The results can help us to understand the relationship between flow hydraulics and sediment generation of slope erosion and offer useful data for the building of erosion model in purple soil.

Modelling of impacts of erosion processes on agricultural landscapes due to intensive rainfall events

2020 ◽  
Author(s):  
Silvia Kohnová ◽  
Zuzana Németová
Keyword(s):  
Soil Erosion ◽  
Soil Degradation ◽  
Agricultural Land ◽  
Assessment Methods ◽  
Rainfall Events ◽  
Degradation Processes ◽  
Erosion Processes ◽  
Erosion Models ◽  
Physically Based ◽  
Physically Based Models

<p>At present, the occurrence of extreme precipitation events is becoming more and more frequent and therefore it is important to quantify their impact on the landscape and soil degradation processes. Until now a wide range of soil erosion models have been developed and many significant studies performed to evaluate soil erosion processes at local and regional level, but there are still many modeling principles that suffer from a range of problems. The general problem in soil erosion modelling lies in the validation and verification of the methodologies used. The validation of erosion models is a very complicated and complex process due to lack of suitable sites, financial demands and due to the high temporal and spatial variability. The paper points to validate the physically and event-based Erosion-3D model predominantly developed to calculate the amounts of soil loss, surface runoff, and depositions resulting from natural and design rainfall events. In the study two different erosion assessment methods were chosen in order to compare diverse evaluation approaches. Both water erosion assessment methods used have certain advantages and disadvantages, but nowadays the use of physically-based models, which are a younger generation of models, are regarded to be a more innovative and effective technique for the evaluation of complex runoff-erosion processes, deposition and transport processes. The significant contribution of physically-based models is seen in their more precise representation of the erosion and deposition processes, a more proper calculation of the erosion, deposition and sediment yields and the application of more complicated characteristics, including fluctuating soil conditions and surface properties in comparison with empirical models. The validation of the models was performed based on the continuous rainfall events for the period selected (2015, 2016 and 2017). The extreme rainfall events occurring during the period were chosen and their serious impact on the agricultural land was modeled. The modelled sediment data were compared with the measured sediment deposition data obtained by a bathymetry survey of the Svacenicky Creek polder. The polder is situated in the middle of the Myjava hill lands in the western part of Slovakia and the bathymetry measurement were conducted using a hydrographical survey using the EcoMapper Autonomous Underwater Vehicle (AUV) device. The results of the study include a comparison between the modelled and measured data and an assessment of the impact of the intensive rainfall events on the investigated territory.</p><p>Key words: intensive rainfall events, agricultural land, soil degradation processes, hydrological extremes, physically-based model</p>

Soil erosion processes. I. The relative importance of rainfall detachment and dunoff entrainment

Soil Research ◽  
1991 ◽  
Vol 29 (5) ◽  
pp. 671 ◽  
Author(s):  
APB Proffitt ◽  
CW Rose
Keyword(s):  
Soil Erosion ◽  
Overland Flow ◽  
Water Flux ◽  
Equilibrium Concentration ◽  
Sediment Concentration ◽  
Soil Types ◽  
Relative Importance ◽  
Runoff Water ◽  
Erosion Processes ◽  
Volumetric Flux

Experiments carried out in a simulated-rainfall tilting-flume facility are reported in which sediment concentrations (c) in runoff water resulting from overland flow only, or from a combination of rainfall and overland flow, were measured under controlled conditions using a series of slopes (0.1, 05, 1, 3 and 5%). The mixture of rainfall (of rate 100 mm h-1) and runon of water at the top of the flume were arranged to provide a constant volumetric flux (1.0x10-3 m3 m-l s-1) at exit from the 5.8 m long flume. Two contrasting soil types were studied: a cracking clay (black earth or vertisol), and a slightly dispersive sandy clay loam (solonchak or aridisol). Two major processes which can contribute to soil erosion under rainfall are rainfall detachment and runoff entrainment. For both soil types, c was generally highest for the steepest slope and decreased with slope. For constant rainfall and/or runoff conditions, c generally decreased with time until an equilibrium concentration was reached. At this equilibrium, the relative importance of rainfall detachment and entrainment in terms of soil loss was dependent on soil type and streampower which incorporates effects of slope and water flux. For streampowers <0.1 W m-2 for the black earth, and <0.3 W m-2 for the solonchak, the greatest contribution to c was by rainfall detachment, whilst at greater streampowers entrainment was the dominant contributor to c. At any streampower, the contribution by rainfall detachment was greater for the weakly structured solonchak than for the well aggregated black earth. At lower strearnpowers, the interaction between erosion processes was found to give higher c than the sum of both sediment concentrations resulting from the separately occurring processes. At streampowers greater than approximately 0.5 W m-2, rainfall reduced eroded sediment concentration by suppressing rill development. The findings in this study suggest that both runoff entrainment and rainfall detachment can contribute to sediment concentration from 'interrill' areas.

scholarly journals Effects of vegetation cover and slope on soil erosion in the Eastern Chinese Loess Plateau under different rainfall regimes

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11226
Author(s):  
Congjian Sun ◽  
Huixin Hou ◽  
Wei Chen
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Water Conservation ◽  
Vegetation Cover ◽  
Interactive Effects ◽  
Chinese Loess Plateau ◽  
Slope Gradient ◽  
Chinese Loess ◽  
Sediment Yields ◽  
Erosion Processes

Soil erosion is a critical environmental problem of the Chinese Loess Plateau (CLP). The effects of vegetation cover on soil erosion reduction under different rainfall types are not well understood especially in the eastern Chinese Loess Plateau (ECLP). In this study, we monitored runoff and sediment yield at the Fengjiagou water and soil conservation station with five types of vegetation cover (arbor trees (ARC), shrubs (SHC), arable (ABC), natural vegetation (NVC), and artificial grass (APC)) and three slope gradients (10°, 15°, and 20°) in the ECLP. Based on long-term monitoring data, five rainfall types were classified by the maximum 30 min rainfall intensity (I30). We also quantitatively revealed the interactive effects of different types precipitation, vegetation cover and slope gradients on regional soil erosion. The results showed that (1) The RII (13 times) and RIII (eight times) type are the most threatening erosive rainfall in this region. (2) The ARC and SHC type were most beneficial for soil and water conservation in the ECLP; The APC and ABC are not conductive to the prevention of regional soil erosion. (3) Runoff and sediment yields increased with the slope gradient. The farmland is vulnerable to soil erosion when the slope gradient exceeds 10°. The results of this study can improve the understanding of regional soil erosion processes on the ECLP and provide useful information for managing regional water and land resources.

The role of the geometry and frequency of rectangular rills in the relationship between sediment concentration and stream power

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1359 ◽  
Author(s):  
B. Fentie ◽  
C. W. Rose ◽  
K. J. Coughlan ◽  
C. A. A. Ciesiolka
Keyword(s):  
Soil Erosion ◽  
Overland Flow ◽  
Sediment Concentration ◽  
Stream Power ◽  
Flume Experiments ◽  
Erosion Processes ◽  
Physically Based ◽  
The Relationship ◽  
Raindrop Impact

We examined, both experimentally and theoretically, whether rilling results in higher soil erosion than would have occurred without rilling. The possibility of rilling occurs when overland flow-driven erosion processes are dominant over erosion due to raindrop impact, and that is the situation assumed in this paper. Stream power (or a quantity related to stream power such as shear stress) is commonly used to describe the driving variable in flow-driven erosion. Five flume experiments were designed to investigate the relationship between stream power and sediment concentration and how this relationship is affected by the ratio of width to depth of flow (r), and the frequency or number of rills per metre width (N) of rectangular rills. This paper presents the results of these experiments and uses a physically based soil erosion theory to show that the results of the 5 flume experiments are in accord with this theory. This theory is used to investigate the effect of all possible rectangular rill geometries and frequencies on the maximum possible sediment concentration, i.e. the sediment concentration at the transport limit, by developing general relationships for the influence of r and N on sediment concentration. It is shown that increased stream power, which can be due to rilling, does not necessarily result in higher sediment concentration.

scholarly journals A Process-Based, Fully Distributed Soil Erosion and Sediment Transport Model for WRF-Hydro

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1840
Author(s):  
Dongxiao Yin ◽  
Z. George Xue ◽  
David J. Gochis ◽  
Wei Yu ◽  
Mirce Morales ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Soil Erosion ◽  
Transport Model ◽  
Model Performance ◽  
Sediment Concentration ◽  
Rain Gauge ◽  
Channel Processes ◽  
Concentration Data ◽  
Rainfall Events ◽  
Sediment Transport Model

A soil erosion and sediment transport model (WRF-Hydro-Sed) is introduced to WRF-Hydro. As a process-based, fully distributed soil erosion model, WRF-Hydro-Sed accounts for both overland and channel processes. Model performance is evaluated using observed rain gauge, streamflow, and sediment concentration data during rainfall events in the Goodwin Creek Experimental Watershed in Mississippi, USA. Both streamflow and sediment yield can be calibrated and validated successfully at a watershed scale during rainfall events. Further discussion reveals the model’s uncertainty and the applicability of calibrated hydro- and sediment parameters to different events. While an intensive calibration over multiple events can improve the model’s performance to a certain degree compared with single event-based calibration, it might not be an optimal strategy to carry out considering the tremendous computational resources needed.

scholarly journals Analyzing Regional Geographic Challenges: The Resilience of Chinese Vineyards to Land Degradation Using a Societal and Biophysical Approach

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 227
Author(s):  
Yang Yu ◽  
Jesús Rodrigo-Comino
Keyword(s):  
Soil Erosion ◽  
Land Degradation ◽  
Environmental Concern ◽  
Point Of View ◽  
Irreversible Damage ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Lack Of Information ◽  
Scientific Hypothesis ◽  
Vineyard Soil

Land degradation, especially soil erosion, is a societal issue that affects vineyards worldwide, but there are no current investigations that inform specifically about soil erosion rates in Chinese vineyards. In this review, we analyze this problem and the need to avoid irreversible damage to soil and their use from a regional point of view. Information about soil erosion in vineyards has often failed to reach farmers, and we can affirm that to this time, soil erosion in Chinese vineyards has been more of a scientific hypothesis than an agronomic or environmental concern. Two hypotheses can be presented to justify this review: (i) there are no official and scientific investigations on vineyard soil erosion in China as the main topic, and it may be understood that stakeholders do not care about this or (ii) there is a significant lack of information and motivation among farmers, policymakers and wineries concerning the consequences of soil erosion. Therefore, this review proposes a plan to study vineyard soil erosion processes for the first time in China and develop a structured scientific proposal considering different techniques and strategies. To achieve these goals, we present a plan considering previous research on other viticultural regions. We hypothesize that the results of a project from a regional geographic point of view would provide the necessary scientific support to facilitate deriving guidelines for sustainable vineyard development in China. We concluded that after completing this review, we cannot affirm why vine plantations have not received the same attention as other crops or land uses.

scholarly journals Soil Erosion Estimates in Arid Region: A Case Study of the Koutine Catchment, Southeastern Tunisia

2021 ◽  
Vol 11 (15) ◽  
pp. 6763
Author(s):  
Mongi Ben Zaied ◽  
Seifeddine Jomaa ◽  
Mohamed Ouessar
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Scientific Evidence ◽  
Field Measurements ◽  
Spatiotemporal Variability ◽  
Soil Conditions ◽  
Storm Events ◽  
Erosion Processes ◽  
Study Results ◽  
Soil Losses

Soil erosion remains one of the principal environmental problems in arid regions. This study aims to assess and quantify the variability of soil erosion in the Koutine catchment using the RUSLE (Revised Universal Soil Loss Equation) model. The Koutine catchment is located in an arid area in southeastern Tunisia and is characterized by an annual mean precipitation of less than 200 mm. The model was used to examine the influence of topography, extreme rainstorm intensity and soil texture on soil loss. The data used for model validation were obtained from field measurements by monitoring deposited sediment in settlement basins of 25 cisterns (a traditional water harvesting and storage technique) over 4 years, from 2015 to 2018. Results showed that slope is the most controlling factor of soil loss. The average annual soil loss in monitoring sites varies between 0.01 and 12.5 t/ha/y. The storm events inducing the largest soil losses occurred in the upstream part of the Koutine catchment with a maximum value of 7.3 t/ha per event. Soil erosion is highly affected by initial and preceding soil conditions. The RUSLE model reasonably reproduced (R2 = 0.81) the spatiotemporal variability of measured soil losses in the study catchment during the observation period. This study revealed the importance of using the cisterns in the data-scarce dry areas as a substitute for the classic soil erosion monitoring fields. Besides, combining modeling of outputs and field measurements could improve our physical understanding of soil erosion processes and their controlling factors in an arid catchment. The study results are beneficial for decision-makers to evaluate the existing soil conservation and water management plans, which can be further adjusted using appropriate soil erosion mitigation options based on scientific evidence.

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