With the onset of the dry season in October 2000 the first bush fires have been depicted in the North of the country, notably in the provinces Ogo and Kanel, by the Centre de Suivi Écologique (CSE), Dakar. Fire detection is based on NOAAA AVHRR data. As of 2 December 2000 the provinces most affected by wildfires are Bala, Kidira, Goudiry, and Ogo (Fig.1).
Fig.1. Fire activity map of Sénégal based on NOAA AVHRR fire detection by the the Centre de Suivi Écologique (CSE), Dakar.
The CSE is a regional node of the World Fire Web.
Background Information of Wildland Fires in the Sénégal Particularly in the Sahelian part of the Sénégal, fire occurrence contributes to increased pressure on agricultural and range land systems through the destruction of natural pasture land and the weakening of agricultural land. The fire activity on the forests of the southern part of the country results in a decrease in the wood productivity as well as a threat on regeneration.
The Government of Sénégal has put means into place to fight the bush fires in the principal eco-geographic zones of the country, through active fire fighting as well prevention activities such as awareness campaigns, and the establishment of a network of fire breaks. One of the most important strategies was introduced in 1965, consisting in prescribing controlled fires early in the season in order to reduce fuel load and therefore to prevent late fires (much larger, more difficult to control and more destructive).
The effectiveness of those strategies goes together with an appropriate use of fire information by the public services as well as the general public. Traditionally, fire information consisted of field reports of observed or fought fires. However, the estimation of burned areas and the fire frequency are fundamental aspects to try to manage the natural resources with respect to fire activity.
Remote sensing of active fires and area burned
To complement traditional fire information, the Centre de Suivi Écologique (CSE) of Dakar has implemented a methodology to monitor fire activity using NOAA-AVHRR data received locally through their own station installed in 1992. While not exhaustive, it is now well accepted that fire information obtain from AVHRR provides good indication of the fire activity over large territory. Initially only the territory of Sénégal was covered, and information operationally used by both the Forestry, Waters, Hunting and Conservation Department and the Livestock Direction. Now the CSE monitoring activities are also contributing to providing fire information for the neighbouring countries. The CSE has also recently become one the nodes of the World Fire Web of the Joint Research Centre (EU). In 1999 an agreement was signed with the Global Fire Monitoring Center (GFMC) which allows the GFMC to disseminate CSE fire products on the GFMC homepage.
The analysis of the fire information over the period 1993 to 1998 has allowed to describe the fire activity in Sénégal and identify important issues that are briefly covered here.
The fire season takes place from October to May. The problematic period is often January to February, when remaining high volume of vegetation is senescent and the whether very dry. During that period large uncontrolled wild fires can be very destructive. The spatial and temporal distribution is generally heterogeneous and variable. Figure 2 illustrates this variability and clearly indicates peak fire activity observed in February 1994 and January 1996. These can mostly been explained by the high rainfall that lead to increased fuel load, as well as unsuccessful prescribed fire activity.
Fig.2. Monthly burned areas in Sénégal between 1993 and 1998
Spatially, as illustrated in Figure 3, fire activity occurs in the centre, South and South-West. Most of the fire activity take place in the regions of Kolda, Tamba and Ziguinchor, because of their continuous herbaceous cover combined with human activities such as honey and gum gathering, hunting and carbonisation. In the North of the country, the little vegetation available is usually used quickly by the cattle and fire activity is consequently very low.
Fig.3. Fire occurrence in Sénégal between 1996 and 1998
Fire management organization The Directorate for Water, Forests, Hunting and Soil Conservation (Direction des Eaux, Forêts, Chasses et Conservation du Sols – DEFCCS) is the main structure responsible for wildland fire management. DEFCCS is promoting fire prevention but is lacking adequate tools and funding. The CSE provides all the information that allows the government to know the fire locations and the size of fires. For fire management purposes the fire maps together with maps of primary production and fire statistics support the recognition of vulnerable areas and the mobilization of fire fighting forces.
The Directorate of Livestock Breeding (Direction de l’Élevage) is in charge of management of the pasture lands which are indispensable for the nutrition of domestic livestock under extensive management common in Sénégal. The Directorate is faced with two major problems. On the one hand wildfires destroy considerable high amounts of important grazing resources, resulting in overgrazing of the remaining vegetated cover. On the other hands the mobility of the migrant (nomadic) pastoralists increases the fire risk. The information generated by the CSE allow the authorities to better manage pasture resources in space and time.
Mussa Drame Centre de Suivi Écologique
pour la gestion des ressources naturelles