The impact of urbanization on the Jakara stream channel morphology, Kano, Nigeria

Abstract

This study examines the influence of urbanization on channel morphology in a watershed that drains Kano metropolis the largest urban centre in Northern Nigeria. Channel sites under different levels of urbanization in the Jakara catchment were sampled. Field surveys were conducted at transects in a total of six reaches of the Jakara channel, two each in fully urban, semi urban and rural sites. Measurements of channel, reach and Planform dimension parameters were used to assess the impact of urbanization. The results indicate high degree of variations in the channel dimension parameters considering that it is a 3^rd order stream. However, all the parameters of full channel dimension show that the urban reach is larger than the semi-urban and rural reaches. The data also indicate that the width and depth increase in the downstream direction, as do crosssectional area and wetted perimeter in the rural reach. The semi urban reach also shows a similar increase in these variables in a downstream direction. The urban reach however, shows a slightly different trend with mean depth, width and cross-sectional area not showing an increasing trend in the downstream direction.