Contribution of remote sensing to wildfire trend and dynamic analysis in two of Ghana’s ecological zones: Guinea-savanna and Forest-savanna mosaic

Abstract

Abstract Background Two of Ghana’s ecological zones—Guinea-savanna zone (GSZ) and Forest-savanna mosaic zone (FSZ)—are practically homologous in terms of structure and floristic composition, with some differences. The various sub-ecosystems that make up these areas are being depleted and losing their natural values due to various threats. There is little understanding about the fire trends in these areas due to lack of data and poor accessibility to existing fire statistics. This study aimed to contribute to the understanding of the trends of area burned and active fire in the Guinea-savanna and Forest-savanna mosaic zones in order to inform policy-makers about sustainable management options. We used the Moderate Resolution Imaging Spectroradiometer (MODIS) daily active fire (MDC14ML) and burned-area (MCD64A1) products to characterize the fire regime in terms of seasonality, intensity, density, a burned area, frequency, and the trends during the study period of 2001 to 2021. Results This study indicated that fire activity started in October and peaked in December (GSZ) and January (FSZ). The mean proportion burned was approximately 39.95% or a burnt area of 2659.31 km2 (FSZ) and 60.05% or a burnt area of 3996.63 km2 (GSZ), while the frequency was approximately 42.87% or 1759.95 of active fires (FSZ) and 57.13% or 2345.26 of active fires (GSZ). In the year 2018 GSZ recorded the largest burned area (19 811.2 km2 or an average of 825.5 km2) with 4719 active points detected whereas the FSZ recorded its greatest burned area in 2015 (8727.4 km2) with 5587 active points recorded, which represents an average of 363.6 km2 of area burned of the total area burned (2001-2021). In addition, it was found that specific times of the day (1000 hours to 1420 hours) recorded the majority of burned areas. Conclusions In conclusion, the trend is decreasing for the area burned, and increasing for the number of fires. This study demonstrated the relevance of remote sensing to describe spatial and temporal patterns of fire occurrence in Ghana and highlighted the need for fire control and fuel management by the policies and institutions (e.i: Ghana National Fire and Rescue Service) in these important and vulnerable zones (GSZ and FSZ), especially in the Forest-Savannah zone, which is increasingly affected by the disasters of wildfires and records more and more of active fires than GSZ. Therefore, rigorous continuous monitoring is essential in collaboration with organizations fighting for the conservation of natural resources in the field is strongly recommended.