GIS-based revised universal soil loss equation for estimating annual soil erosion: a case of lower Kulsi basin, India

Abstract

Assessment and estimation of soil loss is a fundamental aspect of land and water resource conservation and management practices as it provides necessary information in the course of watershed-level development of a region. The soil loss model of Wischmeier and Smith, popularly known as the Revised Universal Soil Loss Equation, was selected to estimate soil loss in the lower Kulsi river basin due to its simplicity, versatility, and flexibility nature method in the Geographic information system platform. Most original governmental datasets, mainly daily gauge rainfall from 2009 to 2018, satellite images for land use land cover, digital elevation model of Shuttle Radar Topographic Mission for topographic factor, and National Bureau of Soil Survey and Land-use Planning, India soil map were utilized to estimate the average annual soil erosion. The estimated average annual soil erosion ranges from 0.0 to 6.45 thousand t ha−1y−1, grouped into low, moderate, high, and very high risk of soil erosion. A basin area of 36.235 km2 (1.85%) basin area was identified as high to very high zones of soil erosion risk and needed immediate conservation measures to reduce the erosion risk.

Estimation of Soil Loss in the Nanoi River Basin using Geospatial Techniques

“…The quantity of soil erosion range varies on the various topographic zone in Nanoi basin. Relevant findings were observed in various river systems within India, including Godavari Middle Sub Basin (9) , Amravati watershed of Tamil Nadu (10) , Chambal River basin (11) , Sadiya region (12) , Panchnoi river basin (13) , lower Kulsi basin (14) and many more. The average annual soil loss rates varied across different regions and higher than Nanoi river basin, the Godavari Middle sub-Basin having 9.88 t/h/y, the Amravati watershed is 280.2 t/h/y, the Chambal River basin is13.44 t/h/y, the Sadiya region encountering 5.45 t/h/y, the Panchnoi river having 5.63 t/h/y and Kulsi river basin is 0 to 6.453 thousand t/h/y.…”

“…The C factor is the crop cover management factor which is derived from the NDVI map with the following formula (14)…”

“…Where α and β are the parameters that determine the shape of the NDVI-C curve. α value of 2 and β value of 1 were taken (14) . The highest mean C-factors, i.e., 1.3 are found in the downstream part of the river basin (Figure 5) namely the villages Ptharighat, Chengeliajhar, Dumunichowki, Khandajan, Kurua, etc.…”

Soil loss modelling in Himalayan region; A case of Tuirial Basin, Mizoram

“…The P value ranges between 0 and 1 (Fig. 12), where close or zero is good conservation management, and close to one is the area of poor conservation management (Vanlalchhuanga et al, 2021;Thakuriah, 2023). The settlement, road construction-affected areas, current cultivation, and fallow land were assigned lower P values, due to bare soil and the cultivation practise on the hill slope, which removed the cover with accelerated high run-off.…”

“…However, in the present study area, the average annual soil loss is estimated at 0-1519.52 t ha − 1 yr − 1 the upper Tuirial watershed, it is estimated at 0-34323.3 t ha − 1 yr − 1 (Barman et al, 2020); and in the northeastern part of India, at Mahadevpur block, the average soil loss is estimated at 0-16843.07 t ha − 1 yr − 1 (Vanlalchhuanga et al, 2022). the western Ghats of Kerala experiencing the same tropical climate, it has been estimated at 0-105.578 t ha − 1 yr − 1 (Thomas et al, 2018), 0 to 6453 t ha − 1 yr − 1 in the lower Kulsi basin of Northeast India (Thakuriah, 2023). Whereas in countries, like Sri Lanka, at the Sabaragamuwa basin, the average annual soil loss is estimated at 0.0-50 t ha − 1 yr − 1 (Senanayake et al, 2020), and in Malaysia, at the Pansoon sub-basin, it is estimated at 0-18473 t ha − 1 yr − 1 (Yusof et al, 2019).…”