Estimation of annual soil erosion dynamics (2005 - 2015) in Pakistan
using Revised Universal Soil Loss Equation (RUSLE)
Abstract
Abrupt changes in climatic factors, exploitation of natural resources,
and land degradation contribute to soil erosion. This study provides the
first comprehensive analysis of annual soil erosion dynamics in Pakistan
for 2005 and 2015 using publically available climatic, topographic, soil
type, and land cover geospatial datasets at 1 km spatial resolution. A
well-accepted and widely applied Revised Universal Soil Loss Equation
(RUSLE) was implemented for the annual soil erosion estimations and
mapping by incorporating six factors; rainfall erosivity (R), soil
erodibility (K), slope-length (L), slope-steepness (S), cover management
(C) and conservation practice (P). We used a cross tabular or change
matrix method to assess the annual soil erosion (ton/ha/year) changes
(2005-2015) in terms of areas and spatial distriburtions in four soil
erosion classes; i.e. Low (<1), Medium (1–5], High
(5-20], and Very high (>20). Major findings of this paper
indicated that, at the national scale, an estimated annual soil erosion
of 1.79 ± 11.52 ton/ha/year (mean ± standard deviation) was observed in
2005, which increased to 2.47 ±18.14 ton/ha/year in 2015. Among seven
administrative units of Pakistan, in Azad Jammu & Kashmir, the average
soil erosion doubled from 14.44 ± 35.70 ton/ha/year in 2005 to 28.03 ±
68.24 ton/ha/year in 2015. Spatially explicit and temporal annual
analysis of soil erosion provided in this study is essential for various
purposes, including the soil conservation and management practices,
environmental impact assessment studies, among others.