| Description |
Fire is a form of natural disturbance that can keep ecosystems in balance, but fire in Africa is neither entirely natural nor anthropogenic due to the hundreds of thousands of years of coexistence between fire and humans. In central Uganda fires can easily reach the size of 200 km and fire is an effective way for farmers and pastoralists to clear away dead grasses that can give way to new growth. There is little to no research on fire as a disturbance in Uganda, nor on relationships between fire and climate and fire and population. Remotely sensed data allow analysis of geographic regions that may have limited access. This study generated a decision tree using six Landsat (TM and EMT+) bands, three indices (Normalized Difference Vegetation Index (NDVI), Normalized Burn Ratio (NBR), and Tassel Cap transformation) and a DEM to produce classified images. Classified images collected in five years had three classes: no burn, new burn and old burn. These classes provided a way to map fires and quantify the area burned in each scene. Population data were gridded and contained population density for the years 1990, 1995, 2000, and 2005, with a spatial resolution of 2.5 degrees, and were provided by the Socioeconomic Data and Applications Center (SEDAC) from Columbia University. Climate data used were reanaylsis datasets from the collaboration by the National Center for Atmospheric Research (NCAR) and the National Centers for Environmental Prediction (NCEP), which provides continuous global climate data from 1948 to present. The three variables analyzed were: precipitation rate, temperature and, soil moisture from 0-10 cm in depth. Within regions of lower populations and drier climates, there was more burned area than in areas of wetter climate and higher population densities. As a result of the coarse spatial resolution of climate and population data, linkages between climate, fire, and people in Uganda were difficult to ascertain. However, this study suggests that in regions with fewer people, more burning occurs regardless of how dry conditions are. |
