Geospatial Analysis of Morphometric Characteristics of River Hawul Basin, North-East Nigeria

Hawul Basin is one of the prominent river basins in north eastern part of Nigeria. In this paper, quantitative techniques which solely involved the use of formula and geospatial techniques (GIS applications) were used to examine the morphometric characteristics (linear, aerial and relief) of the basin. Various formula were adopted to obtain some of the major morphometric characteristics of the basin especially the linear parameters like stream order, stream number, stream length, stream length ratio, bifurcation ratio among others. Geospatial techniques was also used to map out and calculate the distance and areas of the following: relief, drainage, stream order, slope, relative and absolute relief, aspect, ruggedness index, drainage density, stream density and the longitudinal profiles of some selected years of the main river valley. It was revealed in this paper that Hawul Basin is located mainly within the River Gongola plains covering a total land area of 11617.26 km2, out of which 4816.79 km2 (41.46%) lies in Adamawa State and 6726.37 km2 (57.91%) in Borno State and the remaining 74.06 km2 (0.63%) in Yobe State. The major findings of the morphometric characteristics of the basin include: Hawul Basin has high groundwater recharge, low storage capacity and hence, low possibility of flood occurrence. The basin was found to be more of oval than circular or elongated in shape. The basin was also found to be in the early stage of its erosion circle. The basin could also be considered as a region of permeable subsoil material under dense vegetative cover with low relief. Six out of the nine soil types, covering a total land area of 80.45% of the basin were found to be highly permeable. The slope of the basin is gentle with low density of drainage network. The basin has dendritic drainage pattern. It was recommended that two riparian states should harness the potentials of the basin and there should be proper landuse planning and management within the basin in order to maintain and sustain the current environmental conditions of the basin.