Monitoring and modelling of shallow groundwater dynamics in urban context: The case study of Jakarta

Abstract

An overview of the urban shallow groundwater dynamics in Jakarta is provided. The modifications to the water budget at the micro and mesoscale due to anthropogenic influences are described and the diffusive nature of the interaction analysed. The scale of urbanisation (>10 million residents) in conjunction with the lack of infrastructure for water-related services is seen to have fostered a dependency on the shallow groundwater resources and, in turn, led to a tangible impact on the groundwater domain, which is difficult to quantify and study. Using short duration yet high temporal resolution groundwater level data collected at an urban site within Jakarta, two metrics are developed that can describe the daily variation in groundwater levels driven by the human interaction. Numerical models of varying complexity for the urban shallow groundwater dynamics are then used. Here, by employing a process of gradually improving the model’s physical description while performing parameter estimation based on the new metrics, the study provides evidence of the role of the unsaturated zone in influencing the urban shallow groundwater dynamics. We further identify Jakarta’s wastewater seepage as the crucial yet overlooked component of the urban cycle, having direct implications for the region’s water security. The innovation of this study lies at the combination of high temporal resolution data with flexible modelling frameworks that can be developed to give insights into rapidly growing, unstructured stressors on water resources in data poor Mega Cities from the developing world.