The impact of land use dynamics on the soil erosion in the Panchnoi River Basin, Northeast India

Abstract

Land use (LU) dynamics and its relation to the accelerated soil erosion phenomenon in two broad geomorphic divisions of the Panchnoi River basin of Northeast India have studied. The present study was based on the Revised Universal Soil Loss Equation (RUSLE). To measure the impact of the LU dynamics on soil erosion, the basin was divided into two broad geomorphic divisions, i.e., plain zone and hilly zone, and the rate of soil erosion has been estimated separately for both of the geomorphic divisions. It has been found that in the plain zone, LU dynamics significantly accelerated soil erosion-from 0.52 ton/ha/yr in 1990 to 0.94 ton/ha/yr in 2015. Similarly, the vegetation density decreased significantly in the mountainous and hilly zone as the mean Normalized Difference Vegetation Index (NDVI) value changed from 0.45 in 1990 to 0.35 in 2015, which accelerated soil erosion from 12.06 ton/ha/yr to 18.30 ton/ha/yr from 1990 to 2015. The study indicates that soil erosion may give rise to a severe environmental as well as economic problem in the Panchnoi river basin, which may trigger issues related to the soil fertility of the basin area.

Soil loss assessment in Sadiya Region, Assam, India using remote sensing and GIS

“…The RUSLE developed by United States Department of Natural resource conservation service (9) is the principal method used in this study. It is an empirical model used worldwide to estimate soil loss from per unit land on an annual basis (14) . Here, using RUSLE we made an assessment of soil loss from the Sadiya region in a GIS platform.…”

“…The overall schematic flow chart of the RUSLE method is illustrated in the Figure 2. The RUSLE can assess soil loss from a given unit of land on a pixel-by-pixel basis, which is effective while attempting to identify the spatial soil erosion pattern present in a region (14) . The derivative equation of RUSLE is suggested by (10,16)…”

“…However, it can be also applied at a time scale shorter than the year (18) although it has some constraint such as single year data does not include the severe cumulative effect (9) . Thus the R factor is calculated by the following equation suggested by (10) and (14) :…”

“…LS is the dimensionless factor of the RUSLE, its computation is the most complex aspects for relatively large areas (14) . The impact of slope length and steepness reflects on the degree of soil erosion (23) .…”

“…The RUSLE is an improved version of the Universal Soil Loss Equation (USLE) (10) , which includes more diverse enhance methodologies and databases (6) . Due to its reliability and accuracy, several researchers used RUSLE in GIS platform to estimate soil loss in their specific regions, especially in India such as (2,(11)(12)(13)(14) and many more. The findings of this research can help land managers and decision-makers to tackle the damages arise due to soil loss by providing adequate information on soil loss zones and the rates of soil loss.…”