Monitoring Deforestation and Implications for Biodiversity in Nigeria Using Data From NigeriaSat-1 and Other Satellites.

The eco-climatic zones in Nigeria range from the very humid freshwater and mangrove swamps in the south to the semi-arid sahelian zone in the north. These zones support a variety of vegetation; among which the most extensive vegetation zones are savannas in the north and forests in the south. Apart from the traditional role of the Nigerian luxuriant forests in regulating the microclimate and environmental value in terms of biodiversity, they represent an important source of domestic energy.

Available statistics shows that there is a negative correlation between exploitation of the forest and conservation in Nigeria. It has been shown that the area previously characterized by a continuous forest cover has been converted into secondary re-growth vegetation, mainly as a result of shifting cultivation and lumbering. Some initial attempts were made to provide vegetation maps of some parts of Nigeria using aerial photographs. But none of such attempts could depict the status of the forest belts in Nigeria beyond 1970s as aerial photographs of later dates are not available. The Federal Government initiated the Nigerian Radar (NIRAD) project in 1976. The project was based in the Federal Department of Forestry, and employed Side-looking Airborne Radar to obtain radar imagery covering the whole country between October 1976 and March 1977. Unfortunately, this initiative could not be sustained for financial reasons.

It is therefore clear that reliable data base and monitoring system have been part of the major problems inhibiting effective management of forest estate in Nigeria. For the current goals of the National Forestry Programme and Forestry Component of EMP to be achieved, the data needs to be obtained from satellite images and organized in a GIS format for regular updating. Funding constraint has often been the reason for not making use of satellite remote sensing in forestry monitoring and that is what led to the cessation of NIRAD initiative. However, in September 2003, Nigeria (through National Space Research and Development Agency- NASRDA) successfully launched her own satellite (NigeriaSat-1). This makes the country to be the third nation in Africa to join the space age.

NigeriaSat-1 has 3 spectral bands namely; Green: 0.52-0.62µm, Red: 0.63-0.69 µm and NIR: 0.76-0.9 µm. It is one of the Disaster Monitoring Constellation (DMC) satellites and has a swath width of 600km and revisit cycle of 3-5 days. It has spectral resolution comparable to SPOT XS and spatial resolution comparable to Landsat TM. The combination of these characteristics implies that NigeriaSat-1 has great potentials for forestry monitoring. With this satellite in space, the problem of data access for forest monitoring is no longer there and the time is now ripe for utilization of space acquired information in natural resources management. However, there is an urgent need for capacity building in space science technology applications, which is currently below the critical mass, if the country is to derive maximum benefit from NigeriaSat-1.

It is against this background that this pilot project seeks to evolve a GIS base or framework for forest monitoring in Nigeria. Successful implementation of such a project will serve as an impetus for a wide spectrum application of space technology for environmental management in Nigeria, and integration of research results into national planning and development. A GIS based forest monitoring system will make it easy for the country to embark on forest certification programme, which is the new international initiative for combating unsustainable exploitation of the world forests. The ultimate goal of a project centered on developing a framework for GIS based forestry management in Nigeria is to facilitate the ability of the country (now with her own satellite), to utilize space acquired information/data as a basis for policy formulation and management strategy. And with the strategic position of the country within the West Africa sub-region, a successful implementation of such a project is likely to have some trickle down effects on the rest of West Africa.