Groundwater for Sustainable Development 11 (2020) 100431 Available online 25 June 2020 2352-801X/© 2020 Published by Elsevier B.V. Research paper Remote sensing, geological, and geophysical investigation in the area of Ndlambe Municipality, Eastern Cape Province, South Africa: Implications for groundwater potential Mthulisi Mpofu a , Kakaba Madi b, * , Oswald Gwavava a a Department of Geology, University of Fort Hare, Private Bag X1314, Alice, 5700, Eastern Cape, South Africa b School of Biological and Environmental Sciences, Faculty of Agriculture and Natural Sciences, University of Mpumalanga, Private Bag X11283, Nelspruit, 1200, Mpumalanga, South Africa A R T I C L E INFO Keywords: Remote sensing Lineaments Resistivity Groundwater Borehole ABSTRACT Potentiality for groundwater in the Ndlambe Municipality, comprising of rocks of the Witteberg Group, Cape Supergroup, was investigated using a combination of different approaches. Distribution of lineaments extracted from a satellite image is hardly homogenous; their density varies with different localities. Areas around the western and southwestern parts of the study area have relatively high-density values (�39) while the northern, eastern and northeastern parts of the area of study are dominated by low-density values (0-39). Boreholes located in the northeastern part appear to be away from the zones of dense lineaments, have dried up, and were found not to be productive. In the northwest parts of the study area, there are several locations displaying intersections of lineaments, these zones of high lineament intersection can be targeted for groundwater exploration. Most of the lineaments in the study area trend in a northeast-southwest direction; this trend would be identical to the orientation of the preferential fow path. Quartz veins and normal faults seen in the feld are good indicators for groundwater potential as they are a structural expression of extensional environmentsThe same applies to quartz grains affected by extensional micro-fractures, which resulted from brittle deformation as seen under the mi- croscope. Subsurface geology investigation from borehole logging has depicted fractures in quartzitic sandstones; thus, micro-fractures in quartz grains and quartzitic sandstones enhance secondary porosity and groundwater fow. Low resistivities from the geophysical investigation in the study area were inferred to be weathered moist sandstone. The low resistivities at depth also indicate an overlying zone of fractured sandstone and quartzite, hence possibility of hosting some groundwater. Low resistivity zones between two large bodies suggest that the massive rock bodies are being weathered and fractured, and fractures act as conduits for groundwater. 1. Introduction The Ndlambe Municipality is part of the Cacadu District, Eastern Cape Province, South Africa (Fig. 1). The Eastern Cape like other many provinces faces the challenge of groundwater scarcity. In 2018, the City of Cape Town was expecting what was known as “Day Zero”, a day when taps in the city run dry and people start queuing for water. The Eastern Cape Province has, for instance, virtually no groundwater can be found in most of the aquifers (Dept of Water Affairs & Forestry, 2002). There are already problems of supply and quality regarding water provision with an estimated eight million South Africans currently having no ac- cess to potable water (Eberhrd and Pegram, 2000). One-third of all households in South Africa lack access to basic water services with the majority of these being located in rural areas. These historical in- equalities have led to a sound policy of investment of infrastructures for these households. The cost of water will also increase as larger schemes are required to transfer available water to urban centers where the greatest growth in demand is likely to occur. Unless proactive strategic measures are taken to address this water shortage, the macroeconomic impact of water scarcity may have a crippling effect on South Africa’s ability to meet the development requirements of its people. There has also been an associated decrease in water quality associated with both point source effuent discharge and diffuse impacts from land use wash off. The increased interest in recent years in underground sources of water has led to a need for more intensive studies of the geometry and * Corresponding author. E-mail address: Kakaba.Madi@ump.ac.za (K. Madi). Contents lists available at ScienceDirect Groundwater for Sustainable Development journal homepage: http://www.elsevier.com/locate/gsd https://doi.org/10.1016/j.gsd.2020.100431 Received 3 January 2019; Received in revised form 11 April 2020; Accepted 14 June 2020