By: Oyediran E. A.; Akintunde-Alo A. D.;
Abstract:
Catchment areas play critical role in water regulation, soil conservation, and ecosystem health. Yet, the Awba Dam Catchment Basin (ADCB) at the University of Ibadan, Nigeria, lacks detailed information on its delineation, land use land cover (LULC), and water volume dynamics, which hinders sustainable management. Therefore, this study was designed to investigate vegetation cover and water volume dynamics in ADCB using imageries from Da-Jiang Innovations (DJI) Phantom 4 drone over a period one-year (February 2022 to February 2023) at three-month intervals. Unmanned Aerial Vehicle (UAV) imagery was processed using Agisoft Metashape to generate dense point clouds, meshes, Digital Elevation Models (DEM) to produce orthomosaic images. The orthomosaic images were classified into LULC using Maximum Likelihood Algorithm, while water volume was determined using area and volume statistics module algorithm. Three LULC were identified: bare land, vegetation, and water body. Results revealed that significant fluctuations in vegetation and bare land were driven by agricultural activities, from 40.0% and 6.5%, respectively in February 2022 to 71.2% and 39.4%, respectively in February 2023. Water body was lowest (13.4%) in February 2022 and highest (24.1%) in May 2022, while water volume fluctuated from 0.92 GL to 5.04 GL, reflecting seasonal and management influences. Accuracy assessments demonstrated high reliability, with kappa statistics ranging from 80% to 100%. This study underscores the importance of active management practices in shaping land cover changes and highlights the potential of UAV technology for efficient data collection and monitoring in catchment areas. The findings provide valuable insights for sustainable water resource management and ecosystem conservation in the ADCB and similar regions.
Keywords: Catchment Basin; UAV; Land use Land cover; Orthomosaic;
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