One of the key questions for management of legacy mines is to find an affordable way to monitor abandoned sites. Remote sensing provides both active and passive sensing technologies; however, a large skills gap lies between remote sensing technology and the ability to apply it locally. Nearly 40 years of analysed satellite imagery indicates that the Santo Niño site, in the Philippines, has not yet recovered to pre-mining conditions. Though the site shows improvements through time, the resolution of the satellite data is not high enough to assess how local biodiversity has evolved. Drones and associated imaging technologies can deliver centimeter-scale resolution images, solving this issue.

An aim of the Bio+Mine project is to carry out repeated high-resolution multi-drone survey of the entire study site to: i) provide spatio-temporal context to support the interpretation of the other in-situ measurements, ii) collect high-resolution data to inform the decadal results from satellite data, and iii) showcase how drone technology and machine learning can be used to manage natural resources efficiently.

Positive impacts

This project used two drone systems operated by trained graduate and undergraduate students supported by research assistants from the Philippines. Two full site surveys were performed and data delivered a new 3D digital elevation model for the area, providing a baseline for future land stability assessments. Drones also proved to be excellent tools for community outreach, attracting curiosity and engagement with the local population as well as local authorities.

Challenges

The main challenges involved international air travel with drones (including lithium battery transport), difficulty complying with drone flying regulations, and the lack of active signals from the Continuously Operating Reference Stations network in the Philippines. Moreover, deploying drones efficiently and safely in mountainous terrain over vast areas was challenging and required experience.

Lessons learnt and next steps

Going forward, the project aims to train and enroll local partners to fly drones and support the creation of a survey startup. The cost of acquiring new drones limits local engagement. However, work has already begun in partnership with AminoLab, the innovation branch of Dela Salle University, to develop a 2.5 million PHP (~£60,000) entrepreneurship programme capable of supporting approximately ten companies.