Applications of LiDAR-Derived Data in the Operations of the Southern Negros Geothermal Field, Philippines

Abstract

Light Detection and Ranging (LiDAR) is now one of the remote sensing methods commonly used for geothermal resource exploration. LiDAR outputs such as high-resolution digital elevation models (DEMs) are used to delineate faults and identify lineaments to better understand the geologic environment. DEMs are also used to produce high resolution topographic maps and orthorectify images. In the Southern Negros Geothermal Field, airborne LiDAR surveys were conducted in 2014 and 2016 that produced DEMs, 1-meter contour maps and orthophotos. While the primary objective of the surveys was to produce comprehensive topographic maps for engineering applications, the DEMs were also used to further characterize the structural geology of Palinpinon-1 and Palinpinon-2 and ultimately improve drilling targets. In addition, the contour maps and slope maps were used to verify the location and elevation of wellheads and identify possible areas for pad development. The orthophotos also played many practical roles in spatial analyses. Since the Southern Negros Geothermal Field coexists with communities, identifying the affected residents during vertical discharge activities of wells was more accurately made through the creation of distance buffers. Geohazard prone areas were more visible to the geohazard team that often needed quick visual assessment before field inspection. Determining areas that are covered by and still to be applied for tenurial/environmental permits was also made easier through image overlays and visualization. Overall, the present applications of LiDAR data are commendable for spatial analyses, but LiDAR data may be exploited further through integration with GIS applications, additional survey campaigns as well as personnel training and development.