ANALYSIS OF WATERSHED AND STREAM ORDER IN NGASKI LOCAL GOVERNMENT AREA, KEBBI STATE

Isiaka U. A¹, Adebayo, A. ¹, Adamu, S^2, and Mohammed B. N

ABSTRACT

Stream ordering is the quantitative analysis of a watershed. The goal of stream hydrology and ecology is to understand how the spatial structure of stream networks affects the movement of water, energy, and organisms. Understanding how stream networks exhibit a hierarchically branching structure, where conditions at one place in the network may be modified by conditions in related streams, is important for the geographic study of stream network topology (i.e., size and proximity of connected streams). ASTER DEM was downloaded from the NASA website. The software used in this study is ArcGIS 10.8.1 and Microsoft Excel 2021. ArcGIS is used to carry out the analysis and create the final map, while Excel 2021 is used to create some charts. Digital Elevation Model (Fill), Flow Direction, Flow Accumulation, Raster Calculation, Stream Order (Raster), and then Stream Order (Vector) were all generated from the ASTER DEM downloaded from the NASA website. The study shows that there are 838 total streams, of which 54.65% are of first order, 24.34% are of second order, 13.60% are of third order, and 0.84 of the streams are of fifth order. Also, the study further shows that the total length of streams in the Ngaski local government area of Kebbi State is 1506.343542 km, with order one coming first with 58.59% of the total length.

Keywords: Stream order, GIS.