Morphometric analysis and the validity of Hortonian postulations in Anambra drainage basin, Nigeria

Abstract

Anambra drainage basin is decimated by a plethora of rivers emanating from heavy rainfall and fluvio-geomorphic surface processes. Apparently, hydrologic and sedimentologic processes influences basin form and processes which are governed by laws of drainage basin composition postulated by Horton. Metrical dimension provides linearity, topographic and area variables used to validate Horton’s postulates in the Anambra drainage basin. Topographic tools and ARC GIS 10.2 were utilized. The stream number, length and areal quantities showed that the three laws of drainage basin composition postulated by Horton are valid. It is a 6th order dendritic pattern with elongated shape and coarse texture. The drainage density, stream frequency and infiltration number were with low values: 0.10, 0.10 and 0.27 respectively while the overland processes recorded 0.51, implying heavy dissection. The constant of channel maintenance is 0.99 km2. The relief characteristics indicated a low relief. The significance of the morphometric attributes of the Anambra drainage basin has a lot of implications in agricultural practice and erosion processes.