TCarta delivers satellite-derived mangrove health assessment to Abu Dhabi

TCarta, a global provider of geospatial products and services, was commissioned by the Environment Agency — Abu Dhabi (EAD) to carry out a landmark mangrove health assessment covering the entire Emirate of Abu Dhabi. The assessment contained mangrove condition information derived from high-resolution multispectral satellite imagery.

According to TCarta, the report showed 80 percent of the Emirate’s mangrove forests were healthy. The project also enabled EAD to designate conservation areas for immediate protection.

For the assessment, TCarta obtained high-resolution multispectral imagery acquired by the DigitalGlobe WorldView-2 and -3 satellites during from December through March. Computer algorithms were applied to the Coastal Blue, Visible Green, Visible Red and Near Infrared bands to differentiate mangroves from other vegetation across the Emirate.

The company then derived several vegetation indices from the spectral bands to rate the health of the mangrove forests, divided into small grids. From there, TCarta analysts obtained coarse-resolution Landsat imagery from 1987, 2001 and 2017 to chart mangrove coverage over three decades. According to TCarta, the combination of WorldView and Landsat data analysis clearly showed where mangrove loss had occurred over time. This data allowed the company to generate its disturbance index, which correlated health to external factors, such as urban development.

“The satellite-derived vegetation analysis process we developed for this project can be applied to large-area crop and forestry health mapping anywhere in the world,” said Chris Burnett, project manager at TCarta. “As part of the assessment, we created a disturbance index showing precisely where the most mangrove stress is occurring. EAD will use this to determine — and potentially mitigate — the external factors causing the mangrove conditions to decline.”

The company’s research proved that urban development near Abu Dhabi City was one of the primary threats to the Emirate’s mangrove forests. According to TCarta, EAD will use the report for remediation efforts, including the selection of more favorable areas to plant new mangroves to balance those that have already been lost.