Speaker
Mr
Simone Vaccari
(LTS International Ltd.)
Description
Forest degradation is an important source of emissions of carbon dioxide, a greenhouse gas. In many African woodland countries, degradation is a more substantial source of carbon dioxide emissions than deforestation, but degradation cannot be accurately measured using optical remote sensed data such as Landsat. LTS International and the University of Edinburgh have developed FoRAsT (Forest Radar Assessment Tool), an innovative new tool for detecting and measuring forest degradation using radar technology. Radar systems are well suited for assessing aboveground biomass because they are sensitive to woody biomass but not to canopy foliage. Radar can also be used day or night, under any weather conditions.
FoRAsT makes use of the Phased Array L-band Synthetic Aperture RADAR (PALSAR) instrument, which is part of Japan’s Advanced Land Observing Satellite (ALOS). ALOS PALSAR data has been successfully used worldwide to quantify forest aboveground biomass, with especial focus in African woodlands due to its compatibility with the biomass range of up to a maximum of around 300 Mg ha-1, after which the sensor saturates. Up to this level, FoRAsT can estimate forest aboveground biomass with an averaged RMSE of 62 Mg ha-1. The first ALOS mission (ALOS-1) ended in early 2011, whereas the second ALOS mission (ALOS-2) was successfully launched in May 2014 and data was made available from November 2014.
LTS applied the FoRAsT in two different international development projects. In the first project, biomass change in the Sierra Leone/Guinea border region was assessed as part of a USAID and USFS/IP funded climate change mitigation pilot Sustainable & Thriving Environments for West African Regional Development (STEWARD) project. Over 90% of the biomass lost resulted from degradation. These data are being used by the STEWARD project to inform land use decisions and contribute to on-going forest monitoring. LTS also produced a biomass change assessment for priority catchments of the Shire river basin in Malawi as part of an integrated land use management project for the Government of Malawi. Production of biomass maps for 2007 and 2010 enabled the project team to show the spatial pattern of forest degradation over that period. This information is now being used by the Government of Malawi to target interventions in support of sustainable land use management.
The application of FoRAsT, developed with ALOS-1 data, generated promising results in African woodlands in regards to forest aboveground biomass assessment. In order to guarantee application longevity and consistence of the tool, FoRAsT is currently under development to allow simultaneous implementation of ALOS-2 data (from 2014) and ALOS-1 data (timeframe 2007 – 2010). This will allow bridging the gap between 2010 and 2014 in which there were no L-band radar satellites orbiting around the Earth, making it possible to extend forest monitoring assessment in woodland ecosystems of the last decade.
Primary author
Mr
Simone Vaccari
(LTS International Ltd.)
Co-authors
Dr
Casey Ryan
(University of Edinburgh)
Dr
Paddy Abbot
(LTS International Ltd.)
Dr
Philippa Lincoln
(LTS International Ltd.)
