Figure 2 Study workflow.
2.3 Vegetation Surveys
On the same day as the drone
flight, a field survey was conducted to provide ground validation of the
UAV data and subsequent data processing and classification. In order to
maintain the uniformity of species composition, community structure, and
habitat, transects were established using stratified sampling. The
survey design consisted of three transects, selected based on the
characteristics of the underground coal mining faces. Each transect
exhibited distinct key features and demonstrated low spatial
heterogeneity. Within transects,
ten plots were established, comprising four randomly assigned subplots:
tree (30m x 30m), shrub (10m x 10m), and herb (1m x 1m) plots including
replicates (Figure 3). Vegetation species composition was then
identified, and number of individuals, height, and coverage was
recorded. Geomorphological features and vegetation communities were
located and photographed to aid in identification and validation of the
UAV-generated data.