Monitoring the Spatio-Temporal Dynamics of Vegetation Cover in Mubi Region, Adamawa State, Nigeria

摘要

Studies around the world have shown that vegetation cover is undergoing a dramatic change at various scales. Vegetation is a very important component of the ecosystem, its destruction by whatever means will have an adverse effect on the functional role it plays in the environment. Hence, it is necessary to monitor, conserve and utilize these vital resources sustainably. This study monitors vegetation dynamics in Mubi region with the view to understand the status of vegetation cover and suggest possible conservation measures. The study used regression differencing method of change detection to identify the status and dynamics of vegetation cover in the region. Landsat satellite images were used to create Normalized Difference Vegetation Index (NDVI) using IDRISI software. The NDVI images were subjected to diverse analysis ranging from image registration to image regression, differencing and thresholding. The results from these analysis shows that vegetation cover in the region has witnessed unprecedented degradation. In the period between 1987 and 1999 (12 years) the area that experienced depletion in vegetation cover in the region was 10,501.42 hectares while the period between 1999 and 2015 (16 years) witnessed further depletion to 32,701.77 hectares. The areas that experienced restoration in vegetation cover in the region from the period between 1999 and 2015 (24,098.94 hectares) have lower areal extent compared with the period between 1987 and 1999 (44,045.80 hectares). This phenomenon is not unconnected with population growth as the region has witnessed explosive growth in the recent past. This growth in population has resulted in higher demand for food to feed the growing population thereby leading to expansion of farmland. High demands for fuelwood by the increasing populace have also contributed to increase in deforestation. Removal of vegetation cover at such a scale will eventually have negative consequences on the ecosystem as its functional roles in the environment are jeopardized. Hence, there is a need to preserve and conserve vegetal resources through sustainable use.