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

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.

Download Full-text

Fire regimes and soil erosion in north Australian hilly savannas

International Journal of Wildland Fire ◽

10.1071/wf05112 ◽

2006 ◽

Vol 15 (4) ◽

pp. 551 ◽

Cited By ~ 13

Author(s):

Jeremy Russell-Smith ◽

Cameron Yates ◽

Brian Lynch

Keyword(s):

Soil Erosion ◽

Soil Loss ◽

Fire Regimes ◽

Dry Season ◽

Rainfall Erosivity ◽

Storm Events ◽

Wet Season ◽

Continental Scale ◽

Erosion Processes ◽

Intense Storm

Soil erosion is recognised as a major landscape management issue in northern Australia, given highly erodible soils, and high rainfall erosivity associated with low soil surface cover and intense storm events at the commencement of the wet season. Although recent continental-scale erosion modelling addresses such conditions, it does not take account of contemporary fire regimes dominated by annual, late dry season wildfires, especially in extensive higher slope (≥5%) regions of monsoonal Australia. The present paper reports a simple erosion pin assessment at two sites, contrasting soil loss and movement on unburnt and late dry season-burnt hillslopes over one wet season. Although very significant erosion was observed on both unburnt and burnt treatments, overall there was roughly three times the net soil loss and two times more soil movement on late dry season-burnt plots. The landscape scale of late dry season fire regimes, and implications for increased impacts of soil erosion on soil organic matter, nutrients, and ecosystem health are discussed. Collectively, assembled data suggest that more attention needs to be given to understanding and managing the impacts of contemporary fire regimes on hillslope soil erosion processes in the seasonal Australian tropics.

Download Full-text

A Study of the Dynamics of Soil Erosion Using Rusle2 Modelling and Geospatial Tool in Edda-Afikpo Mesas, South Eastern Nigeria

Pakistan Journal of Geology ◽

10.2478/pjg-2020-0007 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Joseph I. Amah ◽

Okechukwu P. Aghamelu ◽

Olufemi V. Omonona ◽

Ikechukwu M. Onwe

Keyword(s):

Soil Erosion ◽

Soil Loss ◽

Slope Failure ◽

Liquid Limit ◽

Storm Events ◽

Remotely Sensed Data ◽

Erosion Processes ◽

Hill Slope ◽

Intense Storm ◽

Very High

AbstractThe Revised Universal Soil Loss Equation (RUSLE) was used to study the soil erosion processes in Edda-Afikpo mesas, Lower Cross River watersheds,Nigeria. The mesas occupy an area estimated at 60km2 on a surface relief of about 284m. DEM data, satellite images and basemap of the area were used. Remotely sensed data were ground-truthed through extensive field works. The results show that the process is facilitated by the Trifecta of hill slope hydrology, geology and land use practices. Steep hill Slope of values 78 % at the major hot spots, very fragile, dry and non-plastic sandy soils all aid sediment detachment. Analysis of the index properties which include Liquid Limit(LL) of 25-30, moisture content(w%) of 5.9-7.4, permeability of 1.541x10-3 – 1.636x10-3 cm/s and shear strength of 36-42 KN/m2 predispose the sediments to detachment and erosion. Based on the analysis, the amount of soil loss in the project area is about 1373.79 ton per year. Soil erosivity factor is high at the mesas(5023.83 MJ mm ha−1 h−1 yr−1 - 5069.51 MJ mm ha−1 h−1 yr−1) The sandy layer attain thickness of 50m-60m in places and with high pore pressure development, slope failure are triggered during intense storm events. In terms of vulnerability level in erosion risk, high to very high constitute 4.1% of the watershed which translate to 5.05km2 of the 59km2. The various processes occur simultaneously and are exacerbated by human factors through seasonal bush burning and development along drainage lines. The study reveals that 18.8% of the available land for development is at high to very high risk of erosion. The soil loss model has been validated and the hotspots from the map coincide with the gully sites. The results of this research can therefore be used for conservation and adaptation purposes.

Download Full-text

Straw mulch impact on soil properties and initial soil erosion processes in the maize field

10.5194/egusphere-egu21-2538 ◽

2021 ◽

Author(s):

Ivan Dugan ◽

Leon Josip Telak ◽

Iva Hrelja ◽

Ivica Kisić ◽

Igor Bogunović

Keyword(s):

Soil Erosion ◽

Soil Water ◽

Soil Loss ◽

Bare Soil ◽

Water Erosion ◽

Straw Mulch ◽

Erosion Processes ◽

Maize Field ◽

Sediment Loss ◽

Initial Soil

Straw mulch impact on soil properties and initial soil erosion processes in the maize fieldIvan Dugan*, Leon Josip Telak, Iva Hrelja, Ivica Kisic, Igor BogunovicUniversity of Zagreb, Faculty of Agriculture, Department of General Agronomy, Zagreb, Croatia(*correspondence to Ivan Dugan: [email protected])Soil erosion by water is the most important cause of land degradation. Previous studies reveal high soil loss in conventionally managed croplands, with recorded soil losses high as 30 t ha-1 under wide row cover crop like maize (Kisic et al., 2017; Bogunovic et al., 2018). Therefore, it is necessary to test environmentally-friendly soil conservation practices to mitigate soil erosion. This research aims to define the impacts of mulch and bare soil on soil water erosion in the maize (Zea mays&#160;L.) field in Blagorodovac, Croatia (45&#176;33&#8217;N; 17&#176;01&#8217;E; 132 m a.s.l.). For this research, two treatments on conventionally tilled silty clay loam Stagnosols were established, one was straw mulch (2 t ha-1), while other was bare soil. For purpose of research, ten rainfall simulations and ten sampling points were conducted per each treatment. Simulations were carried out with a rainfall simulator, simulating a rainfall at an intensity of 58 mm h-1, for 30 min, over 0.785 m2 plots, to determine runoff and sediment loss. Soil core samples and undisturbed samples were taken in the close vicinity of each plot. The results showed that straw mulch mitigated water runoff (by 192%), sediment loss (by 288%), and sediment concentration (by 560%) in addition to bare treatment. The bare treatment showed a 55% lower infiltration rate. Ponding time was higher (p < 0.05) on mulched plots (102 sec), compared to bare (35 sec), despite the fact that bulk density, water-stable aggregates, water holding capacity, and mean weight diameter did not show any difference (p > 0.05) between treatments. The study results indicate that straw mulch mitigates soil water erosion, because it immediately reduces runoff, and enhances infiltration. On the other side, soil water erosion on bare soil under simulated rainstorms could be high as 5.07 t ha-1, when extrapolated, reached as high as 5.07 t ha-1 in this study. The conventional tillage, without residue cover, was proven as unsustainable agro-technical practice in the study area.Key words: straw mulch, rainfall simulation, soil water erosionAcknowledgmentThis work was supported by Croatian Science Foundation through the project "Soil erosion and degradation in Croatia" (UIP-2017-05-7834) (SEDCRO).LiteratureBogunovic, I., Pereira, P., Kisic, I., Sajko, K., Sraka, M. (2018). Tillage management impacts on soil compaction, erosion and crop yield in Stagnosols (Croatia). Catena, 160, 376-384.Kisic, I., Bogunovic, I., Birk&#225;s, M., Jurisic, A., Spalevic, V. (2017). The role of tillage and crops on a soil loss of an arable Stagnic Luvisol. Archives of Agronomy and Soil Science, 63(3), 403-413.

Download Full-text

Estimating Human Impacts on Soil Erosion Considering Different Hillslope Inclinations and Land Uses in the Coastal Region of Syria

Water ◽

10.3390/w12102786 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2786 ◽

Cited By ~ 2

Author(s):

Safwan Mohammed ◽

Hazem G. Abdo ◽

Szilard Szabo ◽

Quoc Bao Pham ◽

Imre J. Holb ◽

...

Keyword(s):

Land Use ◽

Soil Erosion ◽

Land Cover ◽

Soil Loss ◽

Agricultural Land ◽

Human Impacts ◽

Coastal Region ◽

Water Erosion ◽

Land Uses ◽

Erosion Processes

Soils in the coastal region of Syria (CRoS) are one of the most fragile components of natural ecosystems. However, they are adversely affected by water erosion processes after extreme land cover modifications such as wildfires or intensive agricultural activities. The main goal of this research was to clarify the dynamic interaction between erosion processes and different ecosystem components (inclination, land cover/land use, and rainy storms) along with the vulnerable territory of the CRoS. Experiments were carried out in five different locations using a total of 15 erosion plots. Soil loss and runoff were quantified in each experimental plot, considering different inclinations and land uses (agricultural land (AG), burnt forest (BF), forest/control plot (F)). Observed runoff and soil loss varied greatly according to both inclination and land cover after 750 mm of rainfall (26 events). In the cultivated areas, the average soil water erosion ranged between 0.14 ± 0.07 and 0.74 ± 0.33 kg/m2; in the BF plots, mean soil erosion ranged between 0.03 ± 0.01 and 0.24 ± 0.10 kg/m2. The lowest amount of erosion was recorded in the F plots where the erosion ranged between 0.1 ± 0.001 and 0.07 ± 0.03 kg/m2. Interestingly, the General Linear Model revealed that all factors (i.e., inclination, rainfall and land use) had a significant (p < 0.001) effect on the soil loss. We concluded that human activities greatly influenced soil erosion rates, being higher in the AG lands, followed by BF and F. Therefore, the current study could be very useful to policymakers and planners for proposing immediate conservation or restoration plans in a less studied area which has been shown to be vulnerable to soil erosion processes.

Download Full-text

Soil loss due to crop harvesting: significance and determining factors

Progress in Physical Geography Earth and Environment ◽

10.1191/0309133304pp421oa ◽

2004 ◽

Vol 28 (4) ◽

pp. 467-501 ◽

Cited By ~ 45

Author(s):

G. Ruysschaert ◽

J. Poesen ◽

G. Verstraeten ◽

G. Govers

Keyword(s):

Earth Sciences ◽

Soil Erosion ◽

Sugar Beet ◽

Soil Loss ◽

Solanum Tuberosum L ◽

Literature Study ◽

Rock Fragments ◽

Erosion Processes ◽

Denudation Rates ◽

Harvest Technique

Water, wind and tillage erosion are well-studied soil erosion processes. However, there is another process of soil erosion that is rarely considered in the field of earth sciences but one that should not be neglected when calculating soil denudation rates and sediment budgets, i.e., soil loss due to crop harvesting (SLCH). Loose soil and soil adhering to the crop and rock fragments are harvested and exported from the field along with crops such as sugar beet (Beta vulgaris L.), potato (Solanum tuberosum L.) and chicory (Cichorium intybus L.). In this paper several assessments of SLCH found in the literature are listed, revealing that soil loss due to crop harvesting may range from a few Mg up to a few tens of Mg per hectare per harvest. As most literature discussing this soil loss does not originate from the field of earth sciences, and terms used to describe this phenomenon are not standardized, a terminology is proposed to describe soil losses due to crop harvesting compatible with terms used in the field of soil erosion. Furthermore, the parameters determining SLCH are reviewed based on a detailed literature study that focuses mainly on sugar beet. These parameters may be grouped into four factors, i.e. soil, crop, agronomic practices and harvest technique. Variations in soil moisture and soil texture cause the largest variations in SLCH, although other factors, such as harvest technique, also play an important role. Given the importance of SLCH in terms of on-site and off-site effects, more research is needed to quantify SLCH under different environmental conditions.

Download Full-text

Soil loss by water erosion in areas under maize and jack beans intercropped and monocultures

Ciência e Agrotecnologia ◽

10.1590/s1413-70542014000200004 ◽

2014 ◽

Vol 38 (2) ◽

pp. 129-139 ◽

Cited By ~ 2

Author(s):

Pedro Luiz Terra Lima ◽

Marx Leandro Naves Silva ◽

Nilton Curi ◽

John Quinton

Keyword(s):

Soil Erosion ◽

Soil Loss ◽

Soil Management ◽

Bare Soil ◽

Water Erosion ◽

Management Systems ◽

Water Runoff ◽

Jack Bean ◽

Favorable Conditions ◽

Soil Losses

Adequate soil management can create favorable conditions to reduce erosion and water runoff, consequently increase water soil recharge. Among management systems intercropping is highly used, especially for medium and small farmers. It is a system where two or more crops with different architectures and vegetative cycles are explored simultaneously at the same location. This research investigated the effects of maize intercropped with jack bean on soil losses due to water erosion, estimate C factor of Universal Soil Losses Equation (USLE) and how it can be affected by soil coverage. The results obtained also contribute to database generation, important to model and estimate soil erosion. Total soil loss by erosion caused by natural rain, at Lavras, Minas Gerais, Brazil, were: 4.20, 1.86, 1.38 and 1.14 Mg ha-1, respectively, for bare soil, maize, jack bean and the intercropping of both species, during evaluated period. Values of C factor of USLE were: 0.039, 0.054 and 0.077 Mg ha Mg-1 ha-1 for maize, jack bean and intercropping between both crops, respectively. Maize presented lower vegetation cover index, followed by jack beans and consortium of the studied species. Intercropping between species showed greater potential on soil erosion control, since its cultivation resulted in lower soil losses than single crops cultivation, and this aspect is really important for small and medium farmers in the studied region.

Download Full-text

Modelisation Du Risque D’érosion Hydrique Par L’équation Universelle Des Pertes En Terre Dans Le Rif Occidental: Cas Du Bassin Versant De Moulay Bouchta (Maroc)

European Scientific Journal ESJ ◽

10.19044/esj.2018.v14n3p524 ◽

2018 ◽

Vol 14 (3) ◽

pp. 524 ◽

Cited By ~ 2

Author(s):

Anis Zouagui ◽

Mohamed Sabir ◽

Mustapha Naimi ◽

Mohamed Chikhaoui ◽

Moncef Benmansour

Keyword(s):

Soil Erosion ◽

Soil Loss ◽

Erosion Rate ◽

Agricultural Land ◽

Land Development ◽

Principal Component ◽

Slope Length ◽

Increased Risk ◽

Effect Of Support ◽

Soil Losses

Soil erosion causes many environmental and socio-economic problems: loss of biodiversity, decrease in the productivity of agricultural land, siltation of dams and increased risk of flooding. It is therefore essential to establish a detailed evaluation of this process before any spatial planning. To evaluate the effects of soil erosion spatially and quantitatively in order to face this phenomenon, and propose the best conservation and land development strategies, the Universal Soil Loss Equation (USLE) coupled with a geographic information system (GIS) is applied. This model is a multiplication of the five erosion factors: the erosivity of the rain, the erodibility of the soil, the inclination and the slope length, the vegetation cover and the anti-erosion practices. The study area is the Moulay Bouchta watershed (7 889 ha), which is located in the western part of the Rif Mountains, is characterized by a complex and contrasting landscape. The resulting soil loss map shows an average erosion rate of 39.5 (t/ha/yr), 87% of the basin has an erosion rate above the tolerance threshold for soil loss (7 (t/ha/yr)). Soil losses per subbasin range from 16.2 to 81.4 (t/ha/yr). The amount of eroded soil is estimated at 311,591 (t/yr), corresponding to a specific degradation of 12.1 (t/ha/yr). In the absence of any erosion control, 25% of the soil losses would reach the new dam located a little upstream of the basin outlet, reducing its water mobilization capacity to 59,625 (m3/yr). The application of Principal Component Analysis (PCA) to soil erosion factors shows a significant influence of topographic factor (LS) on soil erosion process, followed by the effect of support practices (P), then by soil erodibility (K).

Download Full-text

Erodible fraction content change in long term wind erosion duration

Acta Horticulturae et Regiotecturae ◽

10.2478/ahr-2021-0024 ◽

2021 ◽

Vol 24 (1) ◽

pp. 56-62

Author(s):

Lenka Lackóová ◽

Jana Kozlovsky Dufková

Keyword(s):

Grain Size ◽

Soil Erosion ◽

Wind Erosion ◽

Soil Survey ◽

Biologically Active ◽

Soil Conditions ◽

Agricultural Lands ◽

Erosion Processes ◽

Prevailing Wind Direction ◽

Erodible Fraction

Abstract Soil erosion by wind is the primary land degradation process which affects natural environments and agricultural lands. In agricultural lands, soil erosion by wind mainly results from removing of the finest and most biologically active part of the soil richest in organic matter and nutrients. Repeated exposure to wind erosion can have permanent effects on agricultural soil degradation. Knowing spatial and temporal changes in soil conditions and soil erodibility is essential to understand wind erosion processes. There are many methodologies to predict the susceptibility of landscape to erosion. The more complex is the scheme combining multiple factors, the more accurate the estimate is. There are very few studies on mapping the changes in soil grain size and erodible fraction due to wind erosion. Existing studies only deal with eroded soil units (where particles are removed – deflation) and not the eroded units (areas) to which the eroded particles are wound – accumulated. Prevailing wind direction should also be taken into account when mapping changes in erodible fractions of wind-eroded soils and the nature of the soil (whether soil particles accumulate or deflate). In this study the “historical“ grain size distribution of the soil in three cadastral areas using data from complex soil survey (1968) and year 2018/2019 was analysed. Erodible fraction change was also calculated and compared for both time periods.

Download Full-text

Modeling Runoff-Formation and Soil Erosion after Pumice Excavation at Forested Andosol-Sites in SW-Germany Using WEPP

Soil Systems ◽

10.3390/soilsystems3030048 ◽

2019 ◽

Vol 3 (3) ◽

pp. 48 ◽

Cited By ~ 2

Author(s):

Julian J. Zemke ◽

Joshua Pöhler ◽

Stephan Stegmann

Keyword(s):

Soil Erosion ◽

Land Management ◽

Soil Loss ◽

Annual Runoff ◽

Runoff Generation ◽

Runoff Formation ◽

Clear Cut ◽

Clear Cutting ◽

Erosion Processes ◽

Erosion Prediction

This study investigates the effects of pumice excavation on runoff formation and soil erosion processes in a forested catchment in SW-Germany. The underlying questions are, if (a) backfilled soils have different properties concerning runoff generation and erodibility and if (b) clear-cutting prior to excavation triggers runoff and erosion. Four adjacent sub-areas were observed, which represented different pre- and post-excavation-stages. The basis of the investigation was a comprehensive field sampling that delivered the data for physical erosion modeling using the Water Erosion Prediction Project (WEPP). Modeling took place for standardized conditions (uniform slope geometry and/or uniform land management) and for actual slope geometry and land management. The results show that backfilled soils exhibited 53% increase of annual runoff and 70% increase of annual soil loss under standardized conditions. Storm runoff was increased by 6%, while storm soil loss was reduced by 9%. Land management changes also triggered shifts in annual runoff and soil erosion: Clear-cut (+1.796% runoff, +4.205% soil loss) and bare (+5.958% runoff, +21.055% soil loss) surfaces showed the most distinct changes when compared to undisturbed forest. While reforestation largely diminished post-excavation runoff and soil erosion, the standardized results statistically prove that soil erodibility and runoff generation remain increased after backfilling.

Download Full-text

Modeling of water erosion by the erosion potential method in a pilot subbasin in southern Minas Gerais

Semina Ciências Agrárias ◽

10.5433/1679-0359.2019v40n2p555 ◽

2019 ◽

Vol 40 (2) ◽

pp. 555 ◽

Cited By ~ 2

Author(s):

André Silva Tavares ◽

Velibor Spalevic ◽

Junior Cesar Avanzi ◽

Denismar Alves Nogueira ◽

Marx Leandro Naves Silva ◽

...

Keyword(s):

Soil Loss ◽

Water Erosion ◽

Minas Gerais ◽

Universal Soil Loss Equation ◽

Southeastern Brazil ◽

Erosion Processes ◽

Total Soil ◽

The Mean ◽

Soil Losses ◽

Soil Loss Equation

Soil losses due to water erosion threaten the sustainability of agriculture and the food security of current and future generations. This study estimated potential soil losses and sediment production under different types of land uses in a subbasin in the Municipality of Alfenas, southern Minas Gerais, southeastern Brazil. The objective of this research was to evaluate the application of the Potential Erosion Method by the Intensity of Erosion and Drainage program and correlate the findings with the results obtained by the Revised Universal Soil Loss Equation as well as geoprocessing techniques and statistical analyses. In the Potential Erosion Method, the coefficient indicating the mean erosion intensity was 0.37, which corresponded to erosion category IV and indicated weak laminar erosion processes, and the total soil loss was 649.31 Mg year-1 and the mean was 1.46 Mg ha-1 year-1. These results were consistent in magnitude with those obtained in the Revised Universal Soil Loss Equation, which estimated a mean soil loss of 1.52 Mg ha-1 year-1 and a total soil loss of 668.26 Mg year-1. The Potential Erosion Method suggests that 1.5% of the area presents potential soil losses above the soil loss tolerance limit, which ranged from 5.19 to 5.90 Mg ha-1 year-1, while the Revised Universal Soil Loss Equation indicated that 7.3% of the area has potential soil losses above the limit. The maximum sediment discharge was 60 Mg year-1, meaning that 9.3% of the total soil loss reached the depositional areas of the river plains or watercourses. The Potential Erosion Method was efficient in the evaluation of water erosion in tropical soils, and the results were consistent with models widely employed in the estimation of soil losses. Thus, the model can support the evaluation of soil losses in Brazil and is a robust tool for evaluating the sustainability of agricultural activities.

Download Full-text