Wildfire risk assessment and hotspot analysis in an African savanna ecosystem: the Eastern Okavango Panhandle, Botswana

Abstract

Introduction Seasonal flood pulses in the Okavango Delta stimulate rapid vegetation growth that later dries during the dry season, creating extensive fuel loads that increase wildfire susceptibility in the Eastern Okavango Panhandle (EOP), Botswana. Despite this flood–fire interaction, quantitative and spatially explicit assessments of wildfire risk in the region remain limited. This study addresses this gap by developing a spatial Fire Risk Index (FRI) to identify high-risk areas and persistent wildfire hotspots. Methods Key biophysical variables (vegetation, land surface temperature, and topography) and anthropogenic factors (proximity to roads and settlements) were integrated within a Geographic Information Systems (GIS) framework to generate the FRI. Model performance was evaluated using Receiver Operating Characteristic (ROC) analysis with Moderate Resolution Imaging Spectroradiometer (MODIS) active fire data, producing an Area Under the Curve (AUC) value of 0.77. Spatial clustering of fire occurrences was further examined using Kernel Density Estimation and Getis-Ord Gi* hotspot analysis to identify statistically significant wildfire concentrations. Results and discussion The results indicate that approximately 30% of the landscape falls within moderate fire risk and 21.4% within high fire risk categories. High-risk zones are concentrated in remote, densely vegetated wildlife concessions with high fuel loads and limited accessibility. The NG13 concession emerged as a statistically significant wildfire hotspot (Getis-Ord Gi*, z-score > 2.58, p < 0.01), demonstrating how flood-driven fuel accumulation and human ignition sources interact to shape fire occurrence. By revealing that wildfire risk is concentrated in remote fuel-rich landscapes rather than only near settlements, the findings highlight an access paradox that challenges conventional fire management assumptions in savanna ecosystems. This study therefore provides the first high-resolution spatial framework for understanding wildfire dynamics in the Eastern Okavango Panhandle and supports a paradigm shift from reactive suppression toward proactive, evidence-based prevention through satellite monitoring, targeted fuel management, and strengthened landscape-level fire planning. These insights offer new understanding of how hydrological processes, vegetation structure, and human accessibility jointly shape fire regimes in flood-influenced savanna systems globally.