Mapping Fires in the Lowland Pine Savannas of Southern Belize using Non-Sequential Landsat dNBRs
Climate change and rising populations are increasing wildland fires globally. The use of Landsat imagery is well established for mapping fire scars. However in the tropics where most fires happen its use is constrained by rapid regrowth and high proportion of cloud cover. To overcome this we developed a method of using multiple differenced Normalised Burn Ratios throughout a single year. The enabled a largely complete mapping of burns for a given year, despite large areas of individual scenes being obscured.
The method is demonstrated in three Protected Areas in Southern Belize which are predominantly savanna. We derive the extent of burning in for each single year and inter-annual frequency and variation over a ten year period from 2006 to 2015. We show that one of the Protected Areas had 25% greater burnt area on average over the ten years. This corresponded to a higher frequency of burning than the other protected areas where prescribed burning has been practiced over the last decade. Mapping to visualise burn frequency and extents were developed and tested with local land managers.
The study area is 1800Km2, located in Toledo, Belize (Figure 2). Ecosystems include wetlands, deciduous forest both wet and dry, agriculture, aquaculture (mainly shrimp farms) and the savannas. The PAs are predominantly lowland savanna (Cameron et al. 2011; Meerman & Sabido 2001). The key species are Caribbean Pine (Pinus Caribaea var. hondurensis) and Palmetto Palm (Acoelorrphe wrightii), which are environmentally, and economically important. Directly dependant on Caribbean Pine is the endangered yellow-headed parrot (Amazona Oratrix) and is used for timber. The Palmetto's berries are informally harvested as a seasonal cash income by local people for the production of medicines.