Gully erosion: A comparison of contributing factors in two catchments in South Africa

Mararakanye, N.; Sumner, Paul

doi:10.1016/j.geomorph.2017.03.029

Cited by 51 publications

(26 citation statements)

References 42 publications

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“…It is widely used in studies to calculate gully erosion susceptibility; the method is recognised for its simplicity and robustness is recommended for large areas and where the spatial data is limited [43]. The basic principle of this method is the distribution of gullies in each factor class and is calculated with the help of the following equation:…”

Section: Methodsmentioning

confidence: 99%

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Is Overgrazing Really Influencing Soil Erosion?

Nicu

2018

Water

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Soil erosion is a serious problem spread over a variety of climatic areas around the world. The main purpose of this paper is to produce gully erosion susceptibility maps using different statistical models, such as frequency ratio (FR) and information value (IV), in a catchment from the northeastern part of Romania, covering a surface of 550 km 2 . In order to do so, a total number of 677 gullies were identified and randomly divided into training (80%) and validation (20%) datasets. In total, 10 conditioning factors were used to assess the gully susceptibility index (GSI); namely, elevation, precipitations, slope angle, curvature, lithology, drainage density, topographic wetness index, landforms, aspect, and distance from rivers. As a novelty, overgrazing was added as a conditioning factor. The final GSI maps were classified into four susceptibility classes: low, medium, high, and very high. In order to evaluate the two models prediction rate, the AUC (area under the curve) method was used. It has been observed that adding overgrazing as a contributing factor in calculating GSI does not considerably change the final output. Better predictability (0.87) and success rate (0.89) curves were obtained with the IV method, which proved to be more robust, unlike FR method, with 0.79 value for both predictability and success rate curves. When using sheepfolds, the value decreases by 0.01 in the case of the FR method, and by 0.02 in the case of the success rate curve for the IV method. However, this does not prove the fact that overgrazing is not influencing or accelerating soil erosion. A multi-temporal analysis of soil erosion is needed; this represents a future working hypothesis.

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Section: Methodsmentioning

confidence: 99%

“…Elevation represents a widely used conditioning factor in gully susceptibility analysis [25,43]. Within the study area, this parameter was obtained from the digital elevation model (5 × 5 m/pixel) and reclassified into eight classes using natural breaks (Jenks), as follows: 50.…”

Section: Gully Inventory Map and Conditioning Factorsmentioning

confidence: 99%

Is Overgrazing Really Influencing Soil Erosion?

Nicu

2018

Water

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“…Soil erosion is one of the most severe environmental problems worldwide [1,2]. Soils subjected to a series of degradation processes, such as compaction, nutrient loss and a loss in water storage capacity, result in soil erosion that leads to the loss of fertile arable land [3].…”

Section: Introductionmentioning

confidence: 99%

“…Over the past few decades, numerous studies have addressed the identification, mapping [9,21] and modeling [4,16,17,[22][23][24] of gully erosion. Several parts of eastern South Africa are affected by a range of water erosion processes [1]. The hinterland of Kwa-Zulu Natal (KZN) province is characterized by wide areas of sheet (rill-interrill) erosion and has been affected by multiple episodes of dendritic gully erosion [25].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Gully Erosion Susceptibility Using a Maximum Entropy Model in the Upper Mkhomazi River Basin in South Africa

Bernini

Bosino

Botha

et al. 2021

IJGI

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Soil erosion is one of the most challenging environmental issues in the world, causing unsustainable soil loss every year. In South Africa, several episodes of gully erosion have been documented and clearly linked to the presence of Quaternary colluvial deposits on the Drakensberg Mountain footslopes. The aim of this study was to identify and assess the triggering factors of gully erosion in the upper Mkhomazi River basin in KwaZulu-Natal, South Africa. We compiled a gully inventory map and applied remote sensing techniques as well as field surveys to validate the gully inventory. The gullies were subdivided into slope gullies and fluvial gullies. We derived susceptibility maps based on the spatial distribution of gully types to assess the most important driving factors. A stochastic modeling approach (MaxEnt) was applied, and the results showed two susceptibility maps within the spatial distribution of the gully erosion probability. To validate the MaxEnt model results, a subset of the existing inventory map was used. Additionally, by using areas with high susceptibilities, we were able to delineate previously unmapped colluvial deposits in the region. This predictive mapping tool can be applied to provide a theoretical basis for highlighting erosion-sensitive substrates to reduce the risk of expanding gully erosion.

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“…Gullies are considered one of the most useful indicators of desertification [8,9]. Gully processes have been investigated extensively, and various control practices to mitigate the problems have been conducted worldwide [10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Gully Erosion Control Practices in Northeast China: A Review

Liu

Zhang

et al. 2019

Sustainability

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Gully erosion is the destructive and dramatic form of land degradation in Northeast China. The region is the grain production and ecological security base of China where the fertile and productive Mollisols are distributed. Though the region was agriculturally developed relatively recently, it went through high intensity cultivation and fast succession processes within short-time scales. Coupled with irrational farming practice choice and land use, hillslope erosion and gully erosion are seriously threatening agricultural production and environmental stability in the region. The awareness of gully erosion by the local governments started in the 1970s, and conservation measures were thus implemented. In this paper, based on our survey, communications with local farmers and stakeholders as well as investigation for gully erosion for the past three years, we summarize the practical and efficient practices to manage gully erosion developed by researchers and farmers in Northeast China during the past 50 years. These practices include various drop structures, soil check dams, masonry check dams, gabion check dams, wicker check dams, continuous live wicker, a shrub plant enclosure, and an arbor plant enclosure. We specifically expound how a gully erosion practice is set up and identify the site conditions for which they are well-suited. The application of these practices depends on topography, gully size, and local economy. Bioengineering techniques in Northeast China, such as continuous live wicker, a shrub plant enclosure, and an arbor plant enclosure, are highly effective in controlling gully erosion. Problems and challenges are also presented.

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Gully erosion: A comparison of contributing factors in two catchments in South Africa

Cited by 51 publications

References 42 publications

Is Overgrazing Really Influencing Soil Erosion?

Is Overgrazing Really Influencing Soil Erosion?

Evaluation of Gully Erosion Susceptibility Using a Maximum Entropy Model in the Upper Mkhomazi River Basin in South Africa

Gully Erosion Control Practices in Northeast China: A Review

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