A radar and LiDAR-based earth observation system for monitoring savanna woody structure in southern Africa

Abstract

In southern Africa, landscapes are dominated by savannas, i.e., mixed tree-grass communities. These savannas are threatened by land clearing and degradation, as well as the densification of woody plants, a process known as bush encroachment. There is, however, very limited spatial information on woody cover distribution and changes. Here, we report on the development of an operational system designed to map and monitor woody vegetation cover at a regional scale. This system is based on the combined use of freely available airborne light detection and ranging (LiDAR) data and synthetic aperture radar (SAR) satellite imagery. The integration of these two datasets provides an effective solution for assessing woody fractional cover in southern Africa beyond the level of details and accuracy previously available. Woody fractional cover was mapped at a national scale for South Africa and Namibia in 2010 and 2015 at 1 ha (100 × 100 m) pixel size.