Abstract
GIS and remote sensing approach is an effective tool to determine the morphological characteristics of the basin. Gilgel Abay watershed is stretched between latitude 10.56° to 11.22° N and longitude 36.44° to 37.03° E which is one major contributing river of Lake Tana which is the source of Blue Nile. The present study addressed linear and areal morphometric aspect of the watershed. The study deals with emphasis on the evolution of morphometric parameters such as stream order, stream length, bifurcation ratio, drainage density, stream frequency, texture ratio, elongation ratio, circularity ratio, and form factor ratio. The morphometric analysis of the basin revealed that Gilgel Abay is firth-order drainage basin with total of 662 drainage network, of which 511 are first order, 111 are second order, 30 are third order, 9 are fourth order, and 1 is fifth-order stream. The total length of stream is longer for first order and decrease with increasing stream order. The mean bifurcation ratio is 5.16 which is greater than the standard range, and it indicates that basin is mountainous and susceptible to flooding. Low drainage density is observed which is 0.6 km−2. It indicates that basin is highly permeable and thick vegetation cover. Areal aspect of the morphometric analysis of the basin revealed that the basin is slightly potential to flooding and soil erosion, indicating that runoff generated from the upland area of the watershed is significantly infiltrated at the gentle downstream part and contributing to groundwater potential. Further studies with the help of GIS and remote sensing with high-resolution remote sensing data integrating with ground control data in the field are more effective to formulate appropriate type of natural resource management system.
Highlights
A drainage basin is a part of land where water from rainfall is contributing to a common point
GIS and remote sensing techniques are efficient tools used to analyze the hydrological process of the drainage basin (Waikar and Nilawar 2014)
The Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) shows that the elevation of the Upper Gilgel Abay varies from 1695 m to3543 m a.m.s.l
Summary
A drainage basin is a part of land where water from rainfall is contributing to a common point It is useful element of the catchment, and all flow of water is governed by its properties (Christopher et al 2010). Drainage basin networks exhibit temporal and spatial variations Such runoff patterns change hydrological systems and significantly change both catchment inputs and output such as stream discharge, suspended sediment, solutes and litters, and watershed characters. Water that flows in and out of the basin will deposit and pick up various elements such as sediment, nutrients, and pollutants (Oyegoke and Ifeadi 2008) They can affect both onsite and offsite ecology of the basin. Understanding the drainage basin hydrology is a vital to prior and design proper type of soil and water conservation work
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
