scholarly journals Estimation of Sediment Yield and Maximum Outflow Using the IntErO Model in the Sarada River Basin of Nepal

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 952 ◽  
Author(s):  
Devraj Chalise ◽  
Lalit Kumar ◽  
Velibor Spalevic ◽  
Goran Skataric

Soil erosion is a severe environmental problem worldwide as it washes away the fertile topsoil and reduces agricultural production. Nepal, being a hilly country, has significant erosion disputes as well. It is important to cognise the soil erosion processes occurring in a river basin to manage the erosion severity and plan for better soil conservation programs. This paper seeks to calculate the sediment yield and maximum outflow from the Sarada river basin located in the western hills of Nepal using the computer-graphic Intensity of Erosion and Outflow (IntErO) model. Asymmetry coefficient of 0.63 was calculated, which suggests a possibility of large floods to come in the river basin in the future whereas the maximum outflow from the river basin was 1918 m³ s−1. An erosion coefficient value of 0.40 was obtained, which indicates surface erosion of medium strength prevails in the river basin. Similarly, the gross soil loss rate of 10.74 Mg ha−1 year−1 was obtained with the IntErO modeling which compares well with the soil loss from the erosion plot measurements. The IntErO model was used for the very first time to calculate soil erosion rates in the Nepalese hills and has a very good opportunity to be applied in similar river basins.

Author(s):  
Marie Palíková ◽  
Aleš Kučera

Soil erosion is still an issue in forestry and in human water-resources activities connected with landscape management and the protection of surface waters. The methods recently assessing the water erosion include: monitoring of suspended sediments in water, monitoring of dynamics of soil pro­per­ties, assessing the inclination of soil towards soil erosion, monitoring of effectiveness of erosion control measures, erosion processes modeling etc. (Buzek, 1981; Buzek, 1983; Holý, 1994; Jařabáč, Belský, 2008).The river basin of the water tank Šance is very important as a source of potable water and this importance is advanced, when water tank is clogged up by suspended sediments.Erosion was assessed by two methods in ArcMap 9.3 working with original data: the first method is Universal equation calculating an average annual soil loss from surface (USLE) (Wischmeier, Smith, cit. in Janeček, 2002); the second method assesses the potential erosion (MPE), using specific soil properties as factors, evaluating the rate of the intensity of erosion (Kučera, Palíková; 2009).Each method uses different ways for the description of the erodibility: USLE describes a long-term average annual soil loss as a consequence of surface erosion. It gives exact values of sediments in t . ha−1 . year−1, but from the other point of view, this method is primarily created for an agricultural land. Compared with USLE, MPE solves potential erosion and gives relative values of the erosion tendency of an environment. PME could give a new point of view on the assessing of the erosion.The river basin Ostravice above water tank Šance was used to compare these two methods. As a control measure, dates of the assessment of the water sediments regime (Buzek, 2001) were used. This observation was pursued in waters of the gagin station ČHMÚ Ostrava in Staré Hamry in according Stehlík (1969). This 25-year process of measuring shows the value of 2.47 t . ha−1 . year−1 in water tank upper Ostravice (with surface 72.96 km2). USLE shows much lower values of suspended sediments (0.41 t . ha−1 . year−1 using a continuous longitude of slopes or 0.11 t . ha−1 . year−1, with regards to the interruption of slopes by the forest roads). This difference is caused by the construction of USLE, which doesn’t respect increased values of sediments after the crossing of fords by the forestry mechanization, rill erosion or inputs of sediments from watercourse and near ravines. Therefore, the high values of suspended sediments are mainly caused by forest management (Buzek, 2001).


2014 ◽  
Vol 18 (9) ◽  
pp. 3763-3775 ◽  
Author(s):  
K. Meusburger ◽  
G. Leitinger ◽  
L. Mabit ◽  
M. H. Mueller ◽  
A. Walter ◽  
...  

Abstract. Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959–2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha−1 yr−1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha−1 yr−1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2 = 0.64; p < 0.005) and to the snow deposition sediment yields (R2 = 0.39; p = 0.13). The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based on these results, we conclude that snow gliding appears to be a crucial and non-negligible process impacting soil erosion patterns and magnitude in subalpine areas with similar topographic and climatic conditions.


2012 ◽  
Vol 16 (2) ◽  
pp. 517-528 ◽  
Author(s):  
E. Ceaglio ◽  
K. Meusburger ◽  
M. Freppaz ◽  
E. Zanini ◽  
C. Alewell

Abstract. Mountain areas are widely affected by soil erosion, which is generally linked to runoff processes occurring in the growing season and snowmelt period. Also processes like snow gliding and full-depth snow avalanches may be important factors that can enhance soil erosion, however the role and importance of snow movements as agents of soil redistribution are not well understood yet. The aim of this study was to provide information on the relative importance of snow related processes in comparison to runoff processes. In the study area, which is an avalanche path characterized by intense snow movements, soil redistribution rates were quantified with two methods: (i) by field measurements of sediment yield in an avalanche deposition area during 2009 and 2010 winter seasons; (ii) by caesium-137 method, which supplies the cumulative net soil loss/gain since 1986, including all the soil erosion processes. The snow related soil accumulation estimated with data from the deposit area (27.5 Mg ha−1 event−1 and 161.0 Mg ha−1 event−1) was not only higher than the yearly sediment amounts, reported in literature, due to runoff processes, but it was even more intense than the yearly total deposition rate assessed with 137Cs (12.6 Mg ha−1 yr−1). The snow related soil erosion rates estimated from the sediment yield at the avalanche deposit area (3.7 Mg ha−1 and 20.8 Mg ha−1) were greater than the erosion rates reported in literature and related to runoff processes; they were comparable to the yearly total erosion rates assessed with the 137Cs method (13.4 Mg ha−1 yr−1 and 8.8 Mg ha−1 yr−1). The 137Cs method also showed that, where the ground avalanche does not release, the erosion and deposition of soil particles from the upper part of the basin was considerable and likely related to snow gliding. Even though the comparison of both the approaches is linked to high methodological uncertainties, mainly due to the different spatial and temporal scales considered, we still can deduce, from the similarity of the erosion rates, that soil redistribution in this catchment is driven by snow movement, with a greater impact in comparison to the runoff processes occurring in the snow-free season. Nonetheless, the study highlights that soil erosion processes due to the snow movements should be considered in the assessment of soil vulnerability in mountain areas, as they significantly determine the pattern of soil redistribution.


2020 ◽  
Vol 12 (22) ◽  
pp. 9740
Author(s):  
Benjamin Kipkemboi Kogo ◽  
Lalit Kumar ◽  
Richard Koech

This study examined the impact of land use/cover changes on soil erosion in western Kenya in the years 1995 and 2017. The study used the GIS-based Revised Universal Soil Loss Equation (RUSLE) modelling approach and remote sensing assessment. The results showed that the average soil loss through sheet, rill and inter-rill soil erosion processes was 0.3 t/ha/y and 0.5 t/ha/y, in the years 1995 and 2017, respectively. Of the total soil loss, farms contributed more than 50%, both in 1995 and 2017 followed by grass/shrub (7.9% in 1995 and 11.9% in 2017), forest (16% in 1995 and 11.4% in 2017), and the least in built-up areas. The highest soil erosion rates were observed in farms cleared from forests (0.84 tons/ha) followed by those converted from grass/shrub areas (0.52 tons/ha). The rate of soil erosion was observed to increase with slope due to high velocity and erosivity of the runoff. Areas with high erodibility in the region are found primarily in slopes of more than 30 degrees, especially in Mt. Elgon, Chereng’anyi hills and Elgeyo escarpments. This study forms the first multi-temporal assessment to explore the extent of soil erosion and seeks to provide a useful knowledge base to support decision-makers in developing strategies to mitigate soil erosion for sustainable crop production.


Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 551 ◽  
Author(s):  
Jesús Rodrigo-Comino ◽  
José María Senciales-González ◽  
Enric Terol ◽  
Gaspar Mora-Navarro ◽  
Yeboah Gyasi-Agyei ◽  
...  

To understand soil erosion processes, it is vital to know how the weather types and atmospheric situations, and their distribution throughout the year, affect the soil erosion rates. This will allow for the development of efficient land management practices to mitigate water-induced soil losses. Vineyards are one of the cultivated areas susceptible to high soil erosion rates. However, there is a lack of studies that link weather types and atmospheric conditions to soil erosion responses in viticultural areas. Thus, the main aim of this research is to assess the impacts of weather types and atmospheric conditions on soil erosion processes in a conventional vineyard with tillage in eastern Spain. To achieve this goal, rainfall events from 2006 to 2017 were monitored and the associated runoff and soil loss were collected from experimental plots. Our results showed that the highest volume of runoff and soil erosion is linked to rainfall associated with the eastern winds that accounted for 59.7% of runoff and 63.9% of soil loss, while cold drops in the atmospheric situation classifications emerged as the highest contributor of 40.9% in runoff and 44.1% in soil loss. This paper provides new insights into the development of soil erosion control measures that help to mitigate the negative impact of extreme rainfall and runoff considering atmospheric conditions.


2014 ◽  
Vol 14 (7) ◽  
pp. 1761-1771 ◽  
Author(s):  
S. Stanchi ◽  
M. Freppaz ◽  
E. Ceaglio ◽  
M. Maggioni ◽  
K. Meusburger ◽  
...  

Abstract. Soil erosion in Alpine areas is mainly related to extreme topographic and weather conditions. Although different methods of assessing soil erosion exist, the knowledge of erosive forces of the snow cover needs more investigation in order to allow soil erosion modeling in areas where the snow lays on the ground for several months. This study aims to assess whether the RUSLE (Revised Universal Soil Loss Equation) empirical prediction model, which gives an estimation of water erosion in t ha yr−1 obtained from a combination of five factors (rainfall erosivity, soil erodibility, topography, soil cover, protection practices) can be applied to mountain areas by introducing a winter factor (W), which should account for the soil erosion occurring in winter time by the snow cover. The W factor is calculated from the ratio of Ceasium-137 (137Cs) to RUSLE erosion rates. Ceasium-137 is another possible way of assessing soil erosion rates in the field. In contrast to RUSLE, it not only provides water-induced erosion but integrates all erosion agents involved. Thus, we hypothesize that in mountain areas the difference between the two approaches is related to the soil erosion by snow. In this study we compared 137Cs-based measurement of soil redistribution and soil loss estimated with RUSLE in a mountain slope affected by avalanches, in order to assess the relative importance of winter erosion processes such as snow gliding and full-depth avalanches. Three subareas were considered: DS, avalanche defense structures, RA, release area, and TA, track area, characterized by different prevalent winter processes. The RUSLE estimates and the 137Cs redistribution gave significantly different results. The resulting ranges of W evidenced relevant differences in the role of winter erosion in the considered subareas, and the application of an avalanche simulation model corroborated these findings. Thus, the higher rates obtained with the 137Cs method confirmed the relevant role of winter soil erosion. Despite the limited sample size (11 points), the inclusion of a W factor in RUSLE seems promising for the improvement of soil erosion estimates in Alpine environments affected by snow movements.


2011 ◽  
Vol 2 (2) ◽  
pp. 23-34
Author(s):  
Oon Y.W. ◽  
Chin N.J. ◽  
Law P.L.

 This research presents the results of a study on soil erosion rates and sediment yields of a proposed Level 4 Sanitary Landfill construction site located in Sibu, Sarawak. Assessments on potential soil erosion rates and sediment yields during pre-construction, construction and operation stages were carried out using the Revised Universal Soil Loss Equation (RUSLE) and Modified Universal Soil Loss Equation (MUSLE), respectively. It was found that soil erosion rates during construction and operation stages fell under "Moderately High" category, whereby highest sediment yield occurred during construction and operation stages. Comparative analysis on with and without Best Management Practices (BMPs) during construction stage demonstrated that BMPs could significantly reduce the rate of soil erosion, and thus sediment yields.


AGROFOR ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Abdulvahed KHALEDI DARVISHAN ◽  
Mohamad DERIKVANDI ◽  
Ramyar ALIRAMAEE ◽  
Mohsen KHORSAND ◽  
Velibor SPALEVIC ◽  
...  

Application of empirical models is inevitable because of the complexity of process,features, spatial and temporal variation of soil erosion and non-existence or lack ofassociated data. In the present study, maximum outflow and soil erosion intensitywere predicted for Khamsan representative watershed in West of Iran, using IntEromodel. The results of production of erosion material in the river basin (W year),coefficient of the deposit retention (Ru) and real soil losses (G year) were thencompared with the measured soil erosion, SDR and sediment yield data inKhamsan watershed. The intensity of the erosion process were medium in studiedwatershed. The predicted data were compared with the measured sediment yield ofstudied watershed and verified the acceptable results of the IntEro model inKhamsan representative watershed. The results showed that the peak flow is 27.50m3s-1 for a return period of 100 years. The value of Z coefficient of 0.876 indicatesthat the river basin belongs to the second destruction category out of five. Thecalculated net soil loss from the river basin was 12263.44 m3 per year, specific282.81 m3km-2 per year. The strength of the erosion process is strong, andaccording to the erosion type, it is surface erosion.


2018 ◽  
Vol 98 (1) ◽  
pp. 1-14
Author(s):  
Novica Lovric ◽  
Radislav Tosic

Soil erosion is one of the most significant forms of land degradation in the Bosnia and Herzegovina. The mapping of soil erosion in B&H, as in the study area, was realized 30 years ago (1979-1985). The past decades has been marked by the changes which retained visible tracks and caused numerous changes in the intensity of erosion processes. In this paper, the mapping of the recent state of erosion intensity was performed, and then an analysis of changes was made in relation to the state of 30 years ago. The erosion potential method (EPM) was used for mapping the soil erosion and calculation of gross annual erosion and sediment yield. Erosion Map of the Vrbas river basin was made in the scale of 1:25,000. This Erosion Map counts a total of 69 topographic sections and 4,524 erosion polygons (plots). According to the Erosion Map of the Vrbas river basin, 5,666.88 km2 of the study area is affected by erosion, while 621.71 km2 are accumulating sediments. Annual gross erosion in the Vrbas river basin is 1,223,989.60 m3/year, while sediment yield is 366,088.10 m3/year. These research results are important because this is the first soil erosion map for the Vrbas river basin with EPM methodology for the whole river basin on territory of Bosnia and Herzegovina. The results can be applied in the field of spatial and urban planning, water and soil management on the local and regional level.


2011 ◽  
Vol 8 (5) ◽  
pp. 8533-8563
Author(s):  
E. Ceaglio ◽  
K. Meusburger ◽  
M. Freppaz ◽  
E. Zanini ◽  
C. Alewell

Abstract. Mountain areas are widely affected by soil erosion, which is commonly linked to runoff processes. Also winter processes, like snow gliding and full-depth avalanches, may be important factors that can enhance soil erosion, however the role and importance of snow movements as agents of soil redistribution are not well understood yet. The aim of this study is to provide information on the relative importance of snow related soil erosion processes in comparison to runoff processes. In the study area, which is an avalanche path characterized by intense snow movements and soil erosion, soil redistribution rates were quantified with two methods: (i) by field measurements of sediment yield in an avalanche deposition area during 2009 and 2010 winter seasons; (ii) by Caesium-137 method, which supplies the cumulative net soil loss/gain since 1986, including winter and summer soil erosion processes. The soil erosion rates estimated from the sediment yield at the avalanche deposit area (3.2 and 20.8 Mg ha−1 event−1) is comparable to the yearly erosion rates (averaged since 1986) estimated with the Cs-137 method (8.8–13.4 Mg ha−1 yr−1). The soil accumulation rate estimated with data from the avalanche deposition area (28.2 and 160.7 Mg ha−1 event−1) is even more intense than the yearly deposition rates estimated with Cs-137 (8.9–12.6 Mg ha−1 yr−1). This might be due to the high relevance of the two investigated avalanche events and/or to the discrepancy between the long-term (since 1986) signal of the Cs-137 method compared to rates of 2009 and 2010. Even though the comparability is limited by the different time scale of the applied methods, both methods yielded similar magnitudes of soil redistribution rates indicating that soil erosion due to snow movements is the main driving force of soil redistribution in the area. Therefore winter processes have to be taken into account when assessing soil erosion as they significantly contribute to soil redistribution in mountainous areas.


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