Application of Remote Sensing for Impacts Assessment of Petroleum Activities and Facilities in Bongor Basin, Chad Republic

Abstract

The objective of this study is to compare various changes of ecological parameters within time period prior petroleum activities and after facilities establishment in Bongor basin. Analysis of landsat 7 images from March 24 to April 5, 2000 and that of landsat 8 from February 13, 2015, before and after oil operations respectively, made it possible to extract four biophysical indices, namely: brightness index of soil, moisture index, greenness index and vegetation index. Maps of land use, hydrology and pedology were established from the analysis of multispectral parameters variations. Significant variations between two study periods were then evaluated to be either increasing, declining or stable over the entire Bongor basin and in the areas of the basin under operations. It appears that, shrub savanna has declined by 15.75% over the entire Bongor basin and by 18.90% in the areas of oil operations in Bongor basin. Floodplain and the water body have also declined by 1.59% and 0.0007% respectively over the whole Bongor basin and loss of paddy field. Agricultural area has increased by 15.15% in Bongor basin and by 14.40% in the operations area of Bongor basin, with industrial area occupying 4.49% and the expansion of urbanized area of 0.01%. Silting up of flood zone over the entire Bongor basin has increased by 0.35%. Areas under oil operations, illustrate impacts of activities on soil, trees and groundwater.