Maya Forest Water Resources

Composited Landsat 8 imagery from March - May 2020 with a false color band combination (5, 4, 3). Dark red represents dense vegetation while light red represents less dense vegetation. Open water masks were applied to ALOS-PALSAR-1 images to delineate the water body extent of Laguna Seca in Belize between June 2008 (light blue) and after Tropical Depression 16 in October 2008 (dark blue). Environmental departments can make informed management decisions by monitoring flood-prone areas.

Keywords: Kat Tafoya, ALOS PALSAR 1, Landsat 7, seasonal inundation, forest canopy, wetlands, L-band SAR

Using NASA Earth Observations to Map Forested Inundation in the Maya Forest

As climate change increases the severity and frequency of extreme weather events in the tropics, it is vital for the safety of local communities and the health of ecosystems to monitor seasonal inundation. Forested inundation affects the ability of forested wetlands to provide ecosystem services, such as flood mitigation, water filtration, carbon storage, and erosion mitigation. While ground-based monitoring has traditionally been used to map inundation extent, those methods are costly and time-intensive. The NASA DEVELOP team focused on seasonal inundation throughout 2008 in the Maya Forest, when changes in inundation were drastic. To monitor seasonal inundation, our team used in situ field data and Earth observations from Landsat 7 Enhanced Thematic Mapper (ETM+), Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) 1, Shuttle Radar Topography Mission (SRTM), and products from the Ice, Cloud, and Land Elevation Satellite (ICESat). The team applied a Random Forest algorithm to Landsat 7 imagery, generating an object-level land cover classification with an overall accuracy of 72.1% and forest class with 100% recall and 78% precision. The team applied L-band backscatter thresholds from existing literature to forest-masked ALOS imagery and refined the thresholds in an iterative process using field data and hydrology models to delineate seasonal inundation extent. These publicly available data products help end users from Belize’s Land Information Center (LIC) and Forest Department, Guatemala’s Center for Monitoring and Evaluation (CEMEC), and Mexico’s El Colegio de la Frontera Sur (ECOSUR) to inform land management and protect community infrastructure.

California - JPL
Summer 2021
Ministry of Forestry, Fisheries, Environment & Sustainable Development, Forest Department (Belize)
Ministry of Natural Resources, Land Information Center (Belize)
National Council of Protected Areas, Center for Monitoring and Evaluation (Guatemala)
El Colegio de la Frontera Sur (Mexico)
NASA Goddard Space Flight Center
University of California Santa Barbara, MesoAmerican Research Center
Boles Environmental Consulting
NASA SERVIR Science Coordination Office
NASA Earth Observations
Landsat 7 ETM+
Madelyn Savan (Project Lead)
Kathryn Tafoya
Lara O’Brien
Stephanie Jiménez
Tamara Rudic
Benjamin Holt (NASA Jet Propulsion Laboratory, California Institute of Technology)
Dr. Bruce Chapman (NASA Jet Propulsion Laboratory, California Institute of Technology)
Dr. Emil Cherrington (NASA SERVIR, NASA Marshall Space Flight Center)