Geospatial Data Visualization of Marine Plastic in Davao Gulf Using Python-Data Driven OpenDrift Modeling

Abstract

A growing global problem of marine plastic pollution has resulted from the widespread use of plastic and poor waste management practices, especially in coastal regions like the Davao Gulf in Region XI, Philippines. Thus, this study examined the movement and accumulation of plastic waste in the sea during both dry (November–May) and rainy (June–October) seasons, originating from 39 nearby rivers in the Davao Gulf. This study applies the Python-based OpenDrift framework, which uses the Lagrangian method to track each particle (i.e., plastic) as it moves through time and space. The simulation released 100 synthetic plastic particles per river per month and tracked their trajectories using environmental data, including ocean currents from HYCOM and wind data from NCEP. Results show that during the dry season, plastics tend to drift toward the southwest, reaching as far as Malaysia and Indonesia. In contrast, the rainy season simulations revealed more localized movement, with plastics largely circulating and stranding along the coastlines of Davao Gulf. These findings highlight the significance of seasonal factors in the transport and accumulation of marine debris. By identifying high-risk zones and understanding seasonal drift patterns; this research informs waste management interventions to protect one of the world's most biodiverse marine areas.