Spatial Analysis of the Structural Lineaments and Tectonics of Bulawayo Area in Zimbabwe with Repercussions for Hydrogeological Characteristics of the Crystalline Basement Aquifers

This study reviews the spatial analysis of the geological settings, structural lineaments,
geomorphological landscape and tectonics and their repercussions for hydrogeological characteristics
of the crystalline basement aquifer in Bulawayo, Zimbabwe. In order to establish groundwater
occurrence in basement aquifers, it is important to understand the regional structural lineaments and
regional tectonics as well as the geomorphological settings of the area. Data from aeromagnetic
surveys was also used to extract intrusive structures and different lithology. The integration of the data
sets, individual class weights and map scores which were assessed based on Analytic Hierarchy
Process (AHP) in a geographical information system (GIS) environment helped in producing aquifer
zonation. GIS based Orientation Analysis and Cross section tools (CSTools) was applied to produce
rose diagram from the structural lineaments. Taconites were used to distinguish the essential features
of tectonic movements from the fabricated axes. The results indicated that about 23.45% of the area
was classified good groundwater potential and 31.57% of the area was classified as being moderate
groundwater potential, with over 22.97% being low potential and 22.02% of the area is recognised as
poor. The central part of the study area has high yielding aquifers which are underlain by greenstone
belt compared to the surrounding areas which are underlain by young intrusive granitic rocks of poor
porosity. This was enhanced by potential conduits of groundwater flow in the form of fractured zones
and sheared zones. Further analysis of the groundwater potential zones resulted in dissecting the
high and moderate zones into four major aquifers within Bulawayo urban. These are Matsheumhlope,
Umganwini, Umguza and Lobengula aquifers.