Soil Erosion Protection on Hilly Regions Using Plant Roots: An Experimental Insight
01 Jan 2020-pp 321-335
TL;DR: In this article, an attempt was made to investigate the effect of rainfall in causing gully soil erosion in this landslide-prone area, while considering factors such as varying soil density, slope angle and rainfall intensity.
Abstract: Soil erosion is a major challenge, especially in hilly areas and countries. This study presents the results of erosion control in Nilgiris area, one of the hilly regions in India located at Western Ghats of Tamilnadu. This area experiences gully erosion that causes slope instability. In this study, an attempt was made to investigate the effect of rainfall in causing gully soil erosion in this landslide-prone area, while considering factors such as varying soil density, slope angle and rainfall intensity. The study also investigated the remediation of gully erosion using vetiver, a soil bioengineering approach. A soil simulator filled with the landslide-prone soil with and without the plant roots was used at different slopes. The rate of soil erosion was studied. Soil samples were collected from the simulator and tested for its engineering properties. Results obtained showed that the slope angle has an effect on soil erosion and erosion varies inversely with density. Pore water pressure generation during rainfall creates instability among the topsoil surface, which becomes susceptible to soil erosion. HydroCAD was used in modelling the runoff over the soil surface. Soil erosion was found to occur with an increase in velocity of rainwater, which erodes the top fertile soil and triggers sheet erosion. Generally, the vetiver root was found to be efficient for the minimization of gully erosion in the Nilgiris district.
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TL;DR: In this article, a soil erosion inventory map was prepared using 150 rill and gully erosion prone sites, out of which 70% sample points were randomly chosen for modelling and remaining 30% sites were used for model validation.
Abstract: Soil erosion is one of the major environmental hazards causing severe land degradation in the sub-tropical monsoon dominated Mayurakshi river basin (MRB) of Eastern India. Hence, this study aims to delineate the areas with severe soil erosion probability (SEP) using logistic regression (LR), decision tree (DT), and Random forest (RF). A soil erosion inventory map was prepared using 150 rill and gully erosion prone sites, out of which 70% sample points were randomly chosen for modelling and remaining 30% sites were used for model validation. Alongside, 12 conditioning factors including elevation, curvature, aspect, runoff, TWI, slope, geology, stream frequency, rainfall erosivity, NDVI, LS-factor, and LULC were selected as spatial data base for model building. Multicollinearity among conditioning factors were performed using tolerance (TOL) and variance inflation factor (VIF). The analysis concludes that the possibility of soil erosion is very high in the undulating western parts of Mayurakshi river basin as compared to other sectors. The validation results obtained from ROC curve and kappa statistics is showing that DT and RF reached a higher prediction accuracy than LR model.
32 citations
TL;DR: In this paper, an attempt is made to study the strength variation in a landslide-affected soil by stabilizing the soil with plant roots obtained from readily available plants in the study area.
6 citations
TL;DR: In this article, bioengineering practices were implemented to recover areas affected by gully erosion in a micro-watershed located in the Mixteca, an important region in the Mexican state of Oaxaca.
Abstract: Bioengineering is a technical option which uses selected biological elements to retain soil and rehabilitate areas with gullies. With this aim, bioengineering practices were implemented to recover areas affected by gully erosion in a micro-watershed located in the Mixteca, an important region in the Mexican state of Oaxaca. The restoration plan was to rehabilitate an old stone check dam located in the lower part of the watershed and the establishment of live barriers with Erytrina americana Miller, upstream in the main gullies contributing to the drainage system. To assess the morphometry of the micro-watershed, a digital elevation model was generated by a drone. To assess the efficiency of rehabilitation practices, the volume of sediments retained by the structures was quantified by topographic surveys. Results show that the live barriers combined with the check dam retained as sediments weight 1,304.99 Mg. As the micro-watershed area is 37.06 hectares, without bioengineering structures, the specific degradation would have reached 35.27 Mg ha−1y−1. Thus, sediments retention obtained with the bioengineering system has proven to be efficient in decreasing waterflow speed and initiating the rehabilitation of gullied lands.
1 citations
12 Jan 2023
TL;DR: In this article , the authors calculate the depth of the slip surface on the slope (Lovedale area, The Nilgiris) in the event of a future landslide using Multichannel Analysis of Surface Waves (MASW).
Abstract: Abstract Landslides are one of the prevailing threats to life that causes huge loss to the environment. Around 3.7 million km 2 of the area is exposed to landslides globally and 820,000 km 2 is at high risk for landslides in India. The major triggering factors of landslide in India are rainfall and earthquake. The Nilgiris district which is located in the south-western part of India is more prone to rainfall induced landslides. This study intends to calculate the depth of the slip surface on the slope (Lovedale area, The Nilgiris) in the event of a future landslide using Multichannel Analysis of Surface Waves (MASW). During November 2009 rainfall, a shallow landslide occurred at the toe of this particular slope. Hence, there are more probability for re-occurrence of landslide in the event of rainfall. The shear wave velocity (V s ) obtained from MASW was useful in understanding the variation of the sub-strata and predicting the depth of potential failure surface. The elastic moduli of the soil calculated using empirical relations and software, were compared and one reliable method was considered. The MASW results can be further used for analysing the stability of the slope, reactivation of landslides and landslide early warning system.
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TL;DR: In this article, the authors highlight the need for monitoring, experimental and modelling studies of gully erosion as a basis for predicting the effects of environmental change (climatic and land use changes) on gully degradation rates.
Abstract: Assessing the impacts of climatic and, in particular, land use changes on rates of soil erosion by water is the objective of many national and international research projects. However, over the last decades, most research dealing with soil erosion by water has concentrated on sheet (interrill) and rill erosion processes operating at the (runoff) plot scale. Relatively few studies have been conducted on gully erosion operating at larger spatial scales. Recent studies indicate that (1) gully erosion represents an important sediment source in a range of environments and (2) gullies are effective links for transferring runoff and sediment from uplands to valley bottoms and permanent channels where they aggravate off site effects of water erosion. In other words, once gullies develop, they increase the connectivity in the landscape. Many cases of damage (sediment and chemical) to watercourses and properties by runoff from agricultural land relate to (ephemeral) gullying. Consequently, there is a need for monitoring, experimental and modelling studies of gully erosion as a basis for predicting the effects of environmental change (climatic and land use changes) on gully erosion rates. In this respect, various research questions can be identified. The most important ones are: (1) What is the contribution of gully erosion to overall soil loss and sediment production at various temporal and spatial scales and under different climatic and land use conditions? (2) What are appropriate measuring techniques for monitoring and experimental studies of the initiation and development of various gully types at various temporal and spatial scales? (3) Can we identify critical thresholds for the initiation, development and infilling of gullies in different environments in terms of flow hydraulics, rain, topography, soils and land use? (4) How does gully erosion interact with hydrological processes as well as with other soil degradation processes? (5) What are appropriate models of gully erosion, capable of predicting (a) erosion rates at various temporal and spatial scales and (b) the impact of gully development on hydrology, sediment yield and landscape evolution? (6) What are efficient gully prevention and gully control measures? What can be learned from failures and successes of gully erosion control programmes? These questions need to be answered first if we want to improve our insights into the impacts of environmental change on gully erosion. This paper highlights some of these issues by reviewing recent examples taken from various environments.
1,446 citations
TL;DR: Li et al. as mentioned in this paper reviewed recent studies on impacts, factors and control of gully erosion and update the review on dgully erosion, environmental change: importance and research needs.
Abstract: Gully erosion attracts increasing attention from scientists as reflected by two recent international meetings [Poesen and Valentin (Eds.), Catena 50 (2–4), 87–564; Li et al., 2004. Gully Erosion Under Global Change. Sichuan Science Technology Press, Chengu, China, 354 pp.]. This growing interest is associated with the increasing concern over off-site impacts caused by soil erosion at larger spatial scales than the cultivated plots. The objective of this paper is to review recent studies on impacts, factors and control of gully erosion and update the review on dgully erosion and environmental change: importance and research needsT [Poesen et al., 2003. Catena 50 (2–4), 91–134.]. For the farmers, the development of gullies leads to a loss of crop yields and available land as well as an increase of workload (i.e. labour necessary to cultivate the land). Gullies can also change the mosaic patterns between fallow and cultivated fields, enhancing hillslope erosion in a feedback loop. In addition, gullies tend to enhance drainage and accelerate aridification processes in the semi-arid zones. Fingerprinting the origin of sediments within catchments to determine the relative contributions of potential sediment sources has become essential to identify sources of potential pollution and to develop management strategies to combat soil erosion. In this respect, tracers such as carbon, nitrogen, the nuclear bomb-derived radionuclide 137 Cs, magnetics and the strontium isotopic ratio are increasingly used to fingerprint sediment. Recent studies conducted in Australia, China, Ethiopia and USA showed that the major part of the sediment in reservoirs might have come from gully erosion. Gullies not only occur in marly badlands and mountainous or hilly regions but also more globally in soils subjected to soil crusting such as loess (European belt, Chinese Loess Plateau, North America) and sandy soils (Sahelian zone, north-east Thailand) or in soils prone to piping and tunnelling such as dispersive soils. Most of the time, the gullying processes are triggered by
944 citations
Abstract: A root-soil model developed previously has been extended to predict the amount of increase in soil shear resistance (root reinforcement) produced by stretching, slipping, and breaking roots of various sizes. We measured Young's moduli, tensile strengths, and diameters of pine and barley root
348 citations
TL;DR: The methodological framework identified the potential risk for soil erosion in large-scale zones, and with a more sophisticated model and input data of higher spatial and temporal resolution, results could be specified locally within these risk zones.
281 citations
01 Jan 1996
TL;DR: Sediment production by gully erosion and by interrill and rill erosion in three study areas, representing contrasting agricultural environ- ments (i.e. central Belgium, southeast Portugal and southeast Spain), is assessed through soil erosion mapping and analysis of aerial photos.
Abstract: Sediment production by gully erosion and by interrill and rill erosion in three study areas, representing contrasting agricultural environ ments (i.e. central Belgium, southeast Portugal and southeast Spain), is assessed through soil erosion mapping and analysis of aerial photos. The data indicate that mean annual soil losses due to ephemeral gullying are far from negligible in the studied environments: i.e. 3.6 m3 ha4 year1 in central Belgium, 3.2 m3 ha"1 year"1 in southeast Portugal and 9.7 m3 ha"1 year"1 in southeast Spain. Mean sediment production by ephemeral gully erosion represents 44% of total sediment produced in intensively cultivated small catchments with loess-derived soils, but 80% or more in Mediterranean areas with stony soils. These figures are not constant for the studied environments but vary over time with rainfall intensity and land-use. The limited data available indicate that sediment production due to bank gully erosion is about one order of magnitude smaller than sediment produced by ephemeral gully erosion in central Belgium. The results obtained indicate that more attention should be given to the rate of ephemeral gully erosion when assessing and modelling the impact of environmental change on sediment production.
247 citations