Assess the topographic resolution impact on soil loss

Soil erosion is one of the thorniest issues which has brought severe environmental problems such as degradation of water quality and soil productivity. Topographic factor, as known as slope length and steepness factor (LS) plays a vital role in soil erosion model, it is multiplied with rainfall erosivity (R), ground cover (C), soil erodibility (K) and soil conservation practices factor (P) to modelling soil loss via Revised Universal Soil Loss Equation (RUSLE). In this research, different resolution of elevation model products were used to calculate the LS factor of soil loss, and also compare with each other to access and determine the most appropriate interval to predict soil loss rate in Warrumbungle National Park (WNP). LS factor was calculated via the Digital Elevation Model (DEM) at 30m from Shuttle Radar Topography Mission (SRTM) and High Resolution Light Detection and Ranging (LiDAR) at 1m, 5m and 10m. Twelve soil sites were selected to collect field-based data, which would compare with the soil loss modelling results. GIS technique was applied to model and geo-visualize the LS factor map. Meanwhile, daily soil loss ratio was predicted from LS factor along with rainfall erosivity, groundcover, soil structure and composition.

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