Applications of Unpiloted Aerial Vehicles (UAVs) in Forest Hydrology

Abstract

Unpiloted aerial vehicles (UAVs) are transforming the field of ecohydrology as remote sensing platforms. UAV flight characteristics bring them closer to the land surface, further increasing the achievable spatial resolution of multi-/hyperspectral, thermal infrared (TIR) and light distancing and ranging (LiDAR) measurements and enabling measurement of the land surface at times when clouds obscure the view of satellite- and conventional aircraft-borne sensors. However, it is the low cost of UAVs and the lower operator risk associated with their use that truly define their role as more than a novelty. This chapter focuses on consumer-grade UAVs as platforms for remote sensing, because this category of UAV is much more accessible in terms of cost and regulation to use by the ecohydrologist than military- or aerospace-industry-derived UAVs. The chapter explores the impact of UAV technology on advancing the field of ecohydrology by first reviewing the state of development of consumer-grade UAVs and the remote sensors that can be integrated into these platforms and then discussing the role of UAVs in advancing methods to map forest stand composition, evapotranspiration and snowpack hydrology, respectively. The chapter concludes with a discussion of future needs and potential research directions.