ANALYSIS OF THE MORPHOMETRIC CHANGES IN ARMATAI RIVER CHANNEL KANO SOUTH, NIGERIA

Abstract

The study investigated morphometric changes in Armatai River channel of Kano State, Nigeria. It aimed at analysing the morphometric changes at the river channel between 1986 and 2016. Purposive and systematic sampling techniques were adopted for establishing sampling points at the interval of 4kms apart. Geo spatial data was generated and used in the analysis of Landsat MSS of 2016 and Landsat ETM+ of 1986 all of 30m resolution. Arc GIS 10.3 software was used and ENV 5.1. Digital Elevation Model (DEM) of the study area was produced. Measurements of morphometic variables were carried out using instruments. Results showed relationships among channel width, slope and depth. It also shows that the river channel variables vary between the two study years in such a way that the channel width narrowed at the upper course but widened at lower course while channel depth changed both spatially and temporally and slope changed more temporally. Generally, the mean width changes from about 78m in 1986 to 59m (GIS analysis) and 56m (field measurement) in 2016. For o o slope from about 8 in 1986 to 3 in both GIS and field measurement while average depth of the river changes from 0.18m in 1986 to 0.04 (GIS analysis) due to sedimentation at the lower course in 2016, but increased to 1.03m (field measurement) in2016 due to excessive deepening at the upper course as a result of sand mining. It can be seen that the width of the river decreases and depth increases, this is a clear indication of sand mining implications on the river channel over the years which may reduce both surface and groundwater recharge. It is recommended that findings of this study should be used for sound
planning of water harvesting and groundwater recharge related projects and programmes in the area for development.