Groundwater is a vital resource for domestic, agricultural, industrial activities and ecosystem services. Despite its multi-ple purposes, the resource is under significant threat owing to increasing contamination from anthropogenic activities and climate change. Hence, in order to ensure the reliability and sustainable use of groundwater for the present and future gener-ations, effective management of groundwater (quality and quantity) is highly important. This can be achieved by identifying areas more vulnerable to contamination and implementing protective measures. The present study aims at assessing the vul-nerability of groundwater using GIS-based DRASTIC index in the Quaternary catchment (A21C) within Limpopo River Basin. The vulnerability index varied from 87 to 207. About 53.6% (408 km2) of the catchment area also exhibited high risk of groundwater contamination mostly in central, north-eastern and western part of the sub-catchment. The medium and low vulnerability classes cover only 18.1% (137.5 km2) and 21.7% (165.1 km2) of the study area, respectively. The shallow groundwater at the Doornfontein Campus belongs to very high vulnerability area. The sensitivity analysis indicates that depth to water level, recharge, aquifer media, soil and topography are the important contributors to vulnerability assessment. The correlation analysis performed to validate the final vulnerability map shows a moderate positive correlation, indicating the model’s applicability to the urbanised environment. The study indicates an area that is highly vulnerable to pollution, and hence protective measures are necessary for sustainable management of the groundwater resource in the study area. The result of this study can also be further improved and verified by using other vulnerability assessment models.

The present study aims at evaluating the quality of shallow groundwater (SGW) and its suitability for irrigation purpose in the most urbanised part of Johannesburg city, South Africa. The SGW samples were collected in three consecutive years and analysed for 20 selected physicochemical parameters, and heavy metals. The results were compared with the South African water quality, and Food and Agricultural Organization irrigation water quality guidelines, and standard indices derived from laboratory outputs. The results of the study show that all physiochemical parameters and heavy metals were within the limits set by both guidelines for irrigation purposes, except for potassium (3.58 mg∙dm ^–3) and manganese levels (3.152 mg∙dm ^–3). The calculated irrigation parameter values of sodium adsorption ratio ( SAR), sodium percentage (Na%), residual sodium carbonate ( RSC), magnesium hazard ( MH), Kelly’s ratio ( KR) and permeability index ( PI) were within the permissible range of irrigation water quality standards. The findings of this study provide helpful information for decision-makers such as utilisation of the studied groundwater for irrigation uses.