Researchers use small civilian UAVs to observe and monitor the ecosystem on Bạch Long Vĩ Island in Hải Phòng City. — Photo nhandan.vn

HẢI PHÒNG — Environmental change along the coast of Hải Phòng is becoming harder to ignore. Mangrove belts are thinning in some areas, while coral reefs show signs of stress under growing pressure from both climate change and human activity.

For a coastal city pushing toward green growth and sustainable tourism, these ecosystems are more than just natural assets. They support fisheries, protect shorelines and shape the long-term prospects of local livelihoods. Keeping track of their condition is thus a practical need, not just a scientific task.

But it has not been easy. Field surveys take time, manpower and funding, making it difficult to carry out regularly. Satellite imagery, though widely used, depends heavily on weather and often lacks the resolution needed for detailed assessment. Aerial surveys using manned aircraft can provide clearer data, but costs remain a major constraint.

Facing these limitations, researchers in Hải Phòng are testing a more flexible approach using small civilian drones, or unmanned aerial vehicles (UAVs).

Led by Dr Nguyễn Văn Thảo from the Institute of Oceanography, the project looks at how UAVs equipped with multispectral cameras can support the monitoring of coastal and island ecosystems. Two sites were selected for fieldwork: the Bàng La mangrove forest in Đồ Sơn and coral reef areas around Bạch Long Vĩ Island — both considered among the city’s most representative ecosystems.

Flying at low altitudes, the drones capture high-resolution images that offer a much clearer view than satellite data alone. Surveys can be conducted more frequently and at specific times, allowing researchers to follow changes as they happen rather than relying on scattered observations.

For local managers, this means more timely information to decide where to prioritise protection or adjust activities.

The benefits are particularly visible in coral reef monitoring. Limited underwater visibility often makes it difficult to distinguish between coral, algae and other seabed features during field surveys. Multispectral images collected by UAVs help separate these elements more clearly, making it easier to spot early signs of degradation.

During fieldwork in Bàng La and Bạch Long Vĩ, the research team developed a complete workflow, from data collection to image processing and mapping. Detailed maps of mangrove and coral ecosystems have been produced at a scale of 1:5,000, providing a clearer basis for tracking changes in coverage and distribution.

The results are already being put to use. Data and technical processes have been transferred to the Bạch Long Vĩ Marine Protected Area Management Board, where they support routine monitoring and management work.

The use of small UAVs reflects a broader move toward digital tools in environmental management, in line with the Politburo's Resolution 57-NQ/TW on breakthroughs in science, technology, innovation and national digital transformation.

More importantly, it offers a practical way to keep a closer watch on ecosystems that directly support both livelihoods and the city’s long-term development goals. — VNS