Temporal and Spatial Distribution of Savanna Fires in Senegal and the Gambia, West Africa, 1989-90, Derived From Multi-Temporal AVHRR Night Images

Abstract

Quantitative data on fire regimes from the world's savannas have previously been difficult to obtain due to logistical and scientific reasons. This study addresses the issue for Senegal and The Gambia, West Africa. A bispectral satellite image based method for fire detection has recently been improved and made semi-automatic to provide information on fire regimes of savannas. The method uses thermal night time data from the Advanced Very High Resolution Radiometer (AVHRR) onboard the National Oceanic and Atrnospheric Administration (NOAA) series of weather satellites. Twenty-six near cloud-free AVHRR images have been classified using this method. Though they constitute a small temporal sample, some features of the seasonal periodicity and spatial variations of the region are suggested. Variations in firectivity at the four daily NOAA satellite passing times were recorded from a small field survey in The Gambia, and compared to data from the satellite images. Established relationships between reiative fire activity and data from the various NOAA passes have been used to estimate the maximum daily fire activity at the afternoon passing time. The seasonal variations for the whole study area and regions within are suggested by the estimated maximum values at the twenty-two dates. The locations of fire events in relation to locations of human activities and fuel loadings are examined and a brief summary of the main factors that regulate burning and fire regimes is given.

The sensitivity of CO and aerosol transport to the temporal and vertical distribution of North American boreal fire emissions

“…Satellite observations have shown that forest fires exhibit strong diurnal cycles (Giglio, 2007;Prins et al, 1998;Langaas, 1992;Cahoon et al, 1992;Menzel and Prins, 1996;Eva and Lambin, 1998;Pack et al, 2000). Peak burning typically occurs from 13:00 to 18:30 local time and distinctly earlier in heavily forested regions in the tropics and subtropics (Giglio, 2007).…”

Interannual Changes of Fire Activity in the Protected Areas of the SUN Network and Other Parks and Reserves of the West and Central Africa Region Derived from MODIS Observations

“…For the West Africa region, one could mention the work done by Langaas [21], more particularly on the diurnal fire cycle, or by Kennedy et al [22] and Grégoire [23] on the seasonal distribution. In the specific case of the protected areas of the SUN network, Eva et al [24] and Grégoire and Simonetti [25,26] have done a systematic monitoring of fire activity in these protected areas since 2004.…”

Evaluating the SEVIRI Fire Thermal Anomaly Detection Algorithm across the Central African Republic Using the MODIS Active Fire Product

“…Savanna fires are typically lit earlier in the day [2], and as the day progresses, hotter and drier conditions in the afternoon promote faster fire spread rates, longer active fire perimeters, and increased fireline intensities [3]. After the mid-day peak in optimum burning conditions, air temperature decreases, relative humidity increases, and fire behaviour subsides.…”

“…After the mid-day peak in optimum burning conditions, air temperature decreases, relative humidity increases, and fire behaviour subsides. Whilst smaller agricultural and pastoral fires tend to extinguish during the evening [4], many uncontrolled fires burning across Africa's uninterrupted landscapes persist well into the night [2].…”