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

Abstract

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.

Hydrosedimentological Dynamics in the Guarani Aquifer System, Ribeirão Preto, State of São Paulo, Brazil

“…This increases the vulnerability of GAS in the region where a large part of the local population is concentrated. The piezometric surface reveals drawdown induced by the large concentration of wells and high pumping rates, mainly in the central region of the city (Montenegro et al, 1988;São Paulo, 2008;Conceição et al, 2009). In addition, in the outcrop region of the SAG, the level of groundwater has the lowest depths ( Figure 7A), which coincides with the lowest altitudes.…”

“…With reference to expanding the use of the lowering cone (Conceição et al, 2009) it is suggested the tubular wells be constructed far away from the areas of highest exploitation, using alternate pumping methodologies to enhance the supply; another way is to regularize the water collection in the Rio Pardo subbasin, and set up environmental preservation areas and a vulnerability to pollution zone; one more method would be to improve agricultural management and control the types of fertilizers and pesticides applied and establish maximum permitted limits, in synchrony with intensive environmental education. Therefore, the hydrosedimentological dynamics in the specific area requires assessment to discover the water erosion hot spots, as revealed by the regions that exceed the established TPS limit ( Figure 8B).…”

“…Quantifying the susceptibility to soil loss or sediment production by water erosion helps to evaluate and quantify the sediments that can be carried by water in an area (Sakuno et al, 2020;Chalise et al, 2019;Tavares et al, 2019;Khaledi Darvishan et al, 2019;El Mouatassime et al, 2019;Spalevic et al, 2017). Therefore, crossing these data with the piezometric surface of a specific area can provide an overview of the interactions and the material exchange that occurs.…”

Introductory Chapter: Soil Erosion at a Glance

“…Among the obvious consequences are soil loss and changes in the land surface morphology; yet, the implications go much deeper. It is well documented that soil erosion leads to decline of soil fertility and to considerable loss of productive cultivated and arable land or even to desertification, with serious socioeconomic effects [3][4][5][6][7][8]. A degradation of physical properties of soil involves a decline in soil structure resulting to an increase in bulk density, decrease in total macroporosity, reduction in infiltration, and increase in surface runoff and, finally, in aggravation of soil erosion by water [9].…”

Modelling of Soil Erosion Processes and Runoff for Sustainable Watershed Management: Case Study Oued El Abid Watershed, Morocco

“…For the appropriate sustainable watershed management, land use and landscape planning, which will more effectively meet national or local needs and assists in assessing the consequences of the alternatives the important issue is to quantify the sediments and to estimate sediment yield at the river basin scale (Chalise et al, 2019;Spalevic, 2019;Curovic et al, 2019;Parsipour et al, 2019, Fikfak et al, 2017Popovic et al, 2018). Sediment sampling in the rivers need a lot of time and costly laboratorial works.…”