Drone technology is being deployed to help Sri Lanka manage its water resources more effectively, thanks to the International Water Management Institute (IWMI).

The institute carried out a detailed survey of Badulla, a Sri Lankan town, handing over results to the island nation’s surveyor general in late November. The country’s survey department had asked for help in generating a high-resolution digital elevation model of Badulla, to aid disaster management and mitigation in the region.

Tried and tested conventional survey techniques could have done the job, but it would likely have taken more than a year, according to details from the IWMI. Instead the institute deployed an unmanned aerial vehicle to collect all the data for the detailed map. The most notable difference with this technique is the speed, with the information gathered in 14 flights carried out over three days. The IWMI team covered the roughly 10km2 of town, with the survey delivering a spatial resolution of 4cm, while taking some 4,600 photographs.

The mapping project is not the first time the institute has helped out Sri Lanka with its drone and data skills. Earlier in the year it equipped drones with near-infrared sensors to trial crop monitoring. The particular type of sensor used is able to produce images that make early signs of stress in plants visible, thus indicating if they are under attack from disease or pests, or suffering form a shortage of water or fertilisation.

Data such as this could give farmers up to 10 days advanced warning of problems, before they would become visible to the naked eye, suggested the IWMI research. The trial flights were carried out over the paddy fields in the country’s northern Anuradhapura district, using a Swiss-manufactured eBee fixed-wing drone.