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.

Land use change in all river basins leads to changes in hydrologic response, soil erosion, and sediment dynamics characteristics. Those changes are often viewed as the main cause of accelerated erosion rates. We studied the impact of land use changes on soil erosion processes in one of the watersheds in Montenegro: the Miocki Potok, using this watershed as a pilot river basin for this area. We simulated responses of soil erosion processes by using a process-oriented soil erosion Intensity of Erosion and Outflow (IntErO) model, with different settings of land use for the years 1970, 1980, 1990, 2000, 2010, and 2020. The model provides fast, effective, and affordable insight into the effects of land use change on soil erosion processes. Testing of the applied procedures was important for the further establishment of watershed management methodologies at the national level, for the other 300 river basins of Montenegro. For the current state of land use, calculated peak discharge for the Miocki Potok was 364 m3 s−1 (2020)–372 m3 s−1 (1970) for the incidence of 100 years, and there is a possibility for large flood waves to appear in the studied basin. Real soil losses, Gyear, were calculated at 13680 m3 year−1 (2020) and specific 333 m3 km−2 year−1 (2020). A Z coefficient value of 0.439 (2020) indicated that the river basin belongs to destruction category III. The strength of the erosion process was medium, and according to the erosion type, it was mixed erosion. According to our analysis, the land use changes in the last 50 years influenced a decrease in the soil erosion intensity for 14% in the Miocki Potok River Basin. Further studies should be focused on the detailed analysis of the land use changes trends with the other river basins at the national level, closely following responses of soil erosion to the changed land use structure, and effects of plant-and-soil interaction on soil erosion and sediment dynamics.

No abstract

This paper presents an Ecological-Economic (Eco-Eco) modelling using the Intensity of Erosion and Outflow (IntErO) model for calculation of sediment yield and runoff assessing the impacts of different land covers on soil erosion intensity. Calculations have been made for the Velicka River basin, which is one of 57 sub-basins of the Lim River in the Northeast Montenegro. Several different land use scenarios were then simulated in the model in order to find the optimal scenario of land use for intensive seed potato production. The results of Ecological (Eco-) analysis shown that the real soil loss under current conditions is 18148 m³yr -1 . If seed potato production is introduced, the model calculated a soil loss of 20834 m³yr -1 as sediment yield. In order to balance the damage caused by the introduction of seed potato production we considered also the ecological measure of afforestation to reduce soil loss caused by seed potato production. The model calculated that afforestation would result in a decrease of sediment yield to 17886 m³yr -1 . The results of Economic (-Eco) analysis revealed that the investment of €3,385 per ha for the establishment of the seed potato production will provide the income for the farmers of €15,000 per hectare annually. In parallel, we proposed the investment for the protection of the area (258 ha) with afforestation that amounts to €330,608 (€1,281 per ha), for the period of two years, with no other costs in the next decade. The research results demonstrate that the application of the Eco-Eco modelling, by using the IntErO model for studying the effect of soil erosion and possible land use for intensive seed potato production in the Velicka River Basin provides cost effective solutions for the benefit of the local population.

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.