Overview of the Limpopo regional groundwater level monitoring network, South Africa
摘要
Groundwater monitoring networks provide the main source of information about water levels and water quality within aquifers. In this report, a method is proposed for the preliminary development of groundwater monitoring objectives for an existing network in the Limpopo, South Africa, to obtain groundwater level data of high spatial relevance for better management and reporting of the resource. All existing monitoring stations within the regional network were evaluated to categorize them into baseline and trend monitoring stations and organize them into a corresponding sub-network. The results indicated that 53% of the monitoring stations met the requirement for baseline status and were placed in a primary sub-network for reference monitoring to represent the natural state of groundwater, effects of climate variations on groundwater fluctuations and understand recharge processes from groundwater/surface-water interactions. Meanwhile, 47% of the monitoring stations were characterized as trend monitoring stations and therefore, fall into the secondary sub-network, to provide information of any suspected anthropogenic effects on aquifers. In this sub-network, about 5% of monitoring stations provide information on abstraction for mining activities, 24% on abstractions for agricultural activities, mostly for irrigation, and 19% will monitor abstractions for water supply purposes. The criteria proved to be successful in delivering the desired results, where only a few additional monitoring stations are recommended to fully optimize the Limpopo regional monitoring network, as well as the need to install data loggers in all monitoring boreholes.