Assessment of Outer and Inner Slope Profiles of Volcanic Craters on Biu Plateau, Borno State, Nigeria

This research examined the outer and inner slope profiles of volcanic craters on the Biu Plateau. The objectives of the study are to identify the types of slopes; examine the types of geomorphic processes in the craters; and determine the socio-economic relevance of the craters. Data used for this study were generated from field observations, topographic map, total station survey and group interview. Three sampled craters namely Kumba, Tilla and Jali Tagurmi were purposively selected for the study. Profiles of each craters were plotted using autoCARD where geomorphic processes, and human activities were observed between the stations in relations to slope gradient. Three group interviews and participatory rural appraisal were conducted in the vicinity of each of the craters on the socio-economic importance. Results showed that there are fourteen craters on the Biu plateau; four large (> 300m) in diameter, five medium (200-300m) and five small (< 200m). The morphology of the Kumba crater is conical with an elevation range of 700m to 765m, Tilla crater is circular with elevation range of 736m to 742m while the Jali crater has an oval shape with spot height of 690m to 740m asl. Denudational processes observed on the rims of the craters include weathering, sheet, rill, gully erosions and mass wasting (rock fall, soil creep, debris creep and slides). Socio-economic activities associated with the craters according to group interview and participatory rural appraisal include livestock watering, market gardening, quarrying, tourism, medication and domestic water supply. Other related negative human activities observed include bush burning, deforestation, accelerated erosion, poaching, hunting, and extraction of fuelwood. From the findings of the research it is recommended that public enlightenment campaign on environmental management be conducted, sustainable environmental management of land based resources be ensured. Access roads, afforestation, beneficial cultural practices and tourism be encouraged.