Geospatial-Based Slope Mapping Studies Using Unmanned Aerial Vehicle Technology

Abstract

Unmanned Aerial Vehicle (UAV) is one of the geospatial-based data acquisition technologies which acquire data within a short period for slope mapping studies. Geospatial-based UAV mapping are widely used in many applications, specifically for scientific and mapping research. The capabilities of rapid data acquisition and accessibility to slope risk area are several advantages of using UAV technology. However, the accuracy that influences the output of slope mapping studies using UAV technology need to be considered such as flying altitude and selection of the optimum numbers of Ground Control Points (GCPs). This study focuses on the reviews of geospatial-based UAV mapping, others geospatial-based technologies as well as accuracy assessment of its output. Several considerations were discussed in the production of slope map using UAV technology namely determining the optimum number of GCPs and flying altitudes, as well as evaluating of UAV images. This study presents the production of high resolution slope map area that has been conducted at Kulim, Kedah, Malaysia as the slope location prone to landslide occurrences. Multi-rotor UAV known as DJI Phantom 4 was used for collecting the high resolution images with various flying altitudes. The result of X, Y and Z coordinates show that the accuracy is influenced by the flying altitude of UAV. As for flying altitude is increased, the accuracy of slope mapping is improved. Moreover, the analysis indicated that the slope area coverage and the number of tie point increases as the UAV altitude level also increases.