The Effect of Insurgency on the Spatial Landscape of North Eastern Nigeria

Aliyu Mustapha, Mansir Aminu, Ihenacho Nnaemeka M., Imhanfidon Justin, Muhammad Bala A., David Ebunu, Ezeanya Princess, Oluyomi Olubunmi, Okwenna Nkeiruka, Umar T. Kura

Landscape, Insurgency, land use land cover and Pixel-based classification.

The insurgency in the northeastern Nigeria has adversely affected land uses and land covers in the area. The aim of this research is to evaluate land uses and land covers variations caused by over a decade insurgency in the North Eastern part of Nigeria. Landsat ETM+, Landsat 8 and sentinel-2 imageries acquired in 2008, 2014 and 2020, were used for the study. Pixel-based supervised classification using maximum likelihood algorithm was utilized. Eight land cover classes that include bare surface, wetland, water body, urban, tree cover, grassland, cropland and scrubs cover were identified for classification. The classification accuracy for the three temporal periods were evaluated from the Error matrix of the classified images with an overall accuracy of 75.8%, 80.2% and 84.1% respectively. The classification accuracy results yielded Overall accuracy of 75.8% 80.2% and 84.1% for 2008, 2014 and 2020 images respectively. The quantitative analysis of changes expressed in land area coverage reveals a significant change in the land uses and the land covers. The built up area was 197.87km² in 2008. It increased to 231.28km² in 2014 and to 588.57km² in 2020.  This reveals continuous increase from 0.114% of the total area in 2008 to 0.134% in 2014 and 0.342% in 2020. The area put to crop farming was 105,867.4km² in 2008, which was 61.11% of the total area. It increased to 108,192.10km^2, i.e. 62.85% in 2014, but later decreased in 2020 to 91,478.77km², which is 53.14% of the total area. This shows that there was decrease in agricultural activities in the area in 2020. The natural vegetation cover, which includes grassland, shrubs and tree covers, were 37,808.65km², 16,867km², and 7,041.59km² respectively in 2008. These represented 21.82%, 9.736% and 4.065% of the total area respectively. The shrubs increased to 16,866.6km² in 2014, which was 9.798%, and to 16,978.07km² in 2020 i.e. 9.863% of the total area, while grassland reduced to 35,493.28km² i.e. 20.62% and 28,145.49km²  i.e. 4.055% respectively. The tree cover vegetation in the area reduced to 6,980.07km² i.e. 4.055% of the total area in 2014. Meanwhile, it raised high to 25,526.17km² i.e. 14.83% in 2020. This findings reveal that the total natural vegetation in the area i.e. grassland, shrubs and tree covers, that was 35.625% in 2008, reduced to 34.471 in 2014. Interestingly, it rose to 41.041% of the total area in 2020. Bare surfaces was 1,099.00km² i.e. 0.634% of the total in 2008, but reduced to 1,243.30km² (0.722%) in 2014 and 5,976.64km², which was 3.472% of the total area in 2020. It has been obtained from this study that the area put to cultivation, rose to 62.85% of the study area in 2014, but later decreased in 2020 to 53.14%. This revealed that there was decrease in crop cultivation in that period hence goal two of the SDGs, which is to ensure food security, was threatened in that year.