Spatio-temporal Soil Loss Pattern Analysis of Markham River Basin Through Remote Sensing and GIS Techniques

Abstract

Technological advancements in the application of Remote Sensing (RS) and Geographic Information System (GIS) techniques enable us to estimate river basin characteristics, and soil loss based on different independent parameters. The objectives of this study included spatial mapping of land use and land cover, slope pattern and temporal soil loss pattern of the Markham River basin. Soil loss due to soil erosion was estimated using predictive models such as Universal Soil Loss Equation (USLE) and Revised Universal Soil Loss Equation (RUSLE). Different mandatory input parameters, namely rainfall and runoff factor (R), soil erodibility factor (K), slope length and steepness factor (LS), crop management factor/cover factor (C) and conservation practice factor (P) that were used in RUSLE model, had been derived either from remote sensing data or from conventional data collection systems. Land use / land cover data for year 1992 and 2001 were derived from satellite images using supervised classification techniques to find C factors, which is one of the most important factors for spatio-temporal soil loss analysis. Spatial analysis tool of ArcGIS v-10.1 and model maker tool of ERDAS IMAGINE v-11 software were used to generate all input parameters and to estimate spatio-temporal soil loss. The Markham River basin encompassing an area of about 12765.91sq km was selected as the study area from which an average soil loss of 8.4 tons/acre/year was calculated. The study underscored that the approach of RUSLE model with RS and GIS technologies have great potential for the modeling of different hydrological parameters and the creation of risk maps for any watershed in Papua New Guinea .