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Estimation of Soil Loss and Sediment Yield Using Universal Soil Loss Equation in Jiadhal Basin of Dhemaji District, Assam
Published in Surendra Kumar Chandniha, Anil Kumar Lohani, Gopal Krishan, Ajay Krishna Prabhakar, Advances in Hydrology and Climate Change, 2023
Soil erosion is defined as the process of removal of soil by wind or water of which water is considered to the primary factor. The process of erosion caused by rain water essentially involves dislodgement, movement/transpor-tation and finally settlement/deposition of the transported soil particles as the velocity (kinetic energy) of the water carrying the particles diminishes. Taken together, water and wind are considered responsible to cause degradation of nearly 84% of the land on a global scale. All basins do not erode at the same rate. Even within the same basin, a certain part may erode faster than the other. This means, which part of a basin will erode more than the other parts will depend on a plethora of factors, viz., basin configuration, orientation, the soil erodibility, and the rainfall intensity. Additionally, the rate of erosion largely depends on the land use, land cover, and the land management practices adopted by people within the basin.
Global Climate Change Impacts on Watershed Hydrology
Published in Moonisa Aslam Dervash, Akhlaq Amin Wani, Climate Change Alleviation for Sustainable Progression, 2022
Vishnu Prasad, Abrar Yousuf, Parminder Singh Sandhu
Soil erosion is the removal of surface material by wind or water. It is an irreversible phenomenon that causes land degradation and surface water quality deterioration, etc. Soil erosion is integrally related to land degradation and excessive soil loss resulting from lack of land management has major implications for crop productivity, food security, etc. (Montgomery, 2007). Soil erosion is more common in areas not covered by trees, such as the tilled mountains and hill slopes. Through the rain, the entire top layer of soil is washed away with it, causing erosion. The eroded soil moves down with the excess water and continues to add more and more sediments to it. The effect of climate change is expected to be on soil erosion. Climate changes in temperature and rainfall patterns can influence the production of plant biomass, the rate of soil infiltration, moisture content of the soil, land use/land cover and crop management, thereby impacting both runoff and soil erosion. In the last few decades, close relations have been observed between climate change and soil erosion.
Combating Strategies
Published in Ajai, Rimjhim Bhatnagar, Desertification and Land Degradation, 2022
One of the most common methods for soil and water conservation, adopted all across the world, is to increase the vegetative cover on both, partially vegetated land as well as barren land. In fact, forestry and plantation activities are considered to be the most basic methods followed in combating desertification and land degradation and have been in vogue since ancient times. Increasing vegetation cover leads to a reduction in soil erosion caused by both wind and water, improves soil nutrient status through the increase in soil organic carbon, reduces surface run-off and improves groundwater recharge. All kinds of plant cover (woody, herbaceous or grasses) protect soil against erosion by decreasing the run-off water and by increasing water infiltration into the soil matrix (Puigdefabregas 2005, Zuazo and Pleguezuelo 2008). As plant reduces the velocity of run-off water, the sediment run-off gets reduced, especially on the steep slopes of undulating and hilly terrains. The mechanisms through which vegetation cover reduces the soil erosion and conserve water are the following: (i) plants fix the soil with their roots, thus, protect soil from erosion, (ii) reduce the energy of raindrops with their canopy, (iii) vegetation acts as a physical barrier reducing the velocity of water and sediment flow at the soil surface and (iv) trees/plants also acts as a barrier for wind and reduce wind speed, thereby reducing wind erosion in the arid and semi-arid areas that are prone to wind erosion.
Soil erosion estimation and risk assessment at watershed level: a case study of Neshe Dam Watershed in Blue Nile River basin, Ethiopia
Published in International Journal of River Basin Management, 2023
Israel Tessema, Belay Simane, Kenatu Angassa
Soil erosion can be either natural/geological erosion or accelerated erosion. Natural erosion has been slowly occurring since the early period of the earth, while accelerated erosion is faster and relatively a recent phenomenon happening because of humans’ unwise use of resources. Anthropogenic factors, such as deforestation, overgrazing, incorrect methods of tillage and unscientific agricultural practices, exacerbated the accelerated soil erosion (Lal, 2003; Nyssen et al., 2004; Zhou & Wu, 2008). Soil erosion generates strong environmental impacts and major economic losses from decreased agricultural production to the off-site effects on infrastructure, design-life of constructed reservoirs and dams and the quality of surface water resources by sedimentation processes (Amsalu et al., 2007; Bewket & Teferi, 2009; Haregeweyn et al., 2017).
Modeling sediment yield of Rib watershed, Northwest Ethiopia
Published in ISH Journal of Hydraulic Engineering, 2022
Lewoye Tsegaye Ayalew, Rishikesh Bharti
Researches results indicated that 40% of Ethiopia was once forested but currently the forest cover is less than 4% (Hurni et al. 2010). The large-scale deforestation has resulted in land degradation and soil erosion especially in the Highland of Ethiopia, which constitutes half of the area of the country. Erosion is a natural process that can be hastened by inappropriate land use and land management practices. The high soil erosion in the Highlands of Ethiopia is because of erosive rains, steep slopes and human impact due to improper land management, overgrazing, deforestation, and excessive agricultural production (Ayele et al. 2016). Severe soil erosion in the rugged and mountainous Highland parts of Ethiopia has brought low soil fertility and sedimentation of waterbodies, especially the reservoirs. Loss of soil productivity, degradation of water quality, and less capacity to prevent disasters are among problems caused by soil erosion and sediment deposition. In addition to reducing the water storage capacity, sediment transported to waterbodies can be a source of contamination, which also affects the aquatic life (Hurni 1989). In the intensive agricultural land use areas, nutrients and pesticides are strongly adsorbed onto soil particles and move to waterbodies that result in water pollution (Steegen et al. 2001).
Local perception of watershed degradation in the upper Gibe basin, southwest Ethiopia: implications to sustainable watershed management strategies
Published in International Journal of River Basin Management, 2022
Fekadu Mengistu, Engdawork Assefa
Farmers have also identified the major causes of soil erosion, such as cultivation of steeper slopes through clearing vegetation, runoff, overgrazing and poor farming practices. They have also associated factors, such as limited use of organic input, uninterrupted cropping, and no/limited conservation measures to the soil quality decline. The majority of the respondents (over 75%) also confirmed that they observed a decreasing trend in watershed deterioration following the intervention of watershed management measures indicating that their perception is important to consider while designing appropriate watershed management practices. Various socio-economic, institutional and physical factors affect farmers’ perception on watershed degradation. Farm land size, frequency of extension contact, training services on watershed management intervention practices, access to credit services, group membership and topographic positions affect positively and significantly farmers’ perceptions of watershed degradation. Hence, decision-makers and planners need to consider location and/or socio-economic context-specific efforts to understand all factors that influence farmers’ perception of watershed degradation and towards its restoration activities to up-scaling planning and implementing sustainable watershed management practices in a given landscape.