Monitoring Mangrove Reforestation in Sri Lanka

Image above: Mangrove ecosystems around Batticaloa Lagoon, Sri Lanka taken January 11, 2023. © 2023, Planet Labs PBC. All Rights Reserved.

In 2015, Sri Lanka made history as the first nation to take strides to protect the full extent of their mangroves. Along the coastlines of Sri Lanka, these valuable mangrove ecosystems protect the country from natural hazards, including erosion and tsunamis. However, due to large natural disasters and anthropogenic deforestation from increased urbanization, Sri Lanka’s mangroves have faced degradation over the years. For instance, the country’s Batticaloa Lagoon is a major mangrove habitat that was hit by the 2004 Indian Ocean tsunami. Following this devastating event, the country worked on reforestation of the region, and a research project grown out of Thu Dau Mot University in Vietnam used satellites to collect concrete data on the outcome of these reforestation initiatives. The study leverages PlanetScope data alongside Landsat, Sentinel-2, and RapidEye to analyze mangrove cover and land change surrounding the lagoon. The study estimated that in 2022, the region still had 26% less mangrove coverage than in 1995. While 20% of the mangrove depletion has been attributed to the 2004 Indian Ocean tsunami, this analysis revealed that despite the reforestation projects following the tsunami, additional mangrove depletion from natural hazards and urbanization has continued in the region. This study helps provide the current status of mangroves in the region to inform future reforestation and management decisions. 

The full study can be found in the Journal of Coastal Conservation.