Role of water quality and groundwater fluctuations as precursors in sustainable development and management of groundwater resources

Water quality and hydrogeological studies conducted in the Tammileru and Vamsadhara River basins and in the coastal and urban aquifers of Visakhapatnam, India, have provided critical information on the anomalous behaviour of ionic concentrations and their ratios, which are specific to different hydrogeological conditions. The ionic ratios of the groundwater in the Tammileru basin have proved to be an effective tool for identifying the Geological formations, while their transient behaviour has provided major clues for evaluating the point and non-point sources of contamination, which otherwise were not evident from field observations. The field and model studies in the urban and coastal aquifers of Visakhapatnam have clearly brought out contradicting relationships between the rise and fall of the water table and the associated ionic concentrations, which can be explained only with specific hydrogeological models. Low permeability values suggest high contact time resulting in enrichment through adsorption of common ions. Contrasting behaviour of fluoride reflects the presence of F-bearing minerals and adsorption phenomena. A holistic approach will provide suitable monitoring and management strategies for sustainable development and management of groundwater resources.