Interconnected Hydrogeological and Hydrological Systems in Volcanic Aquifer Deposits: A Conceptual Model Based on Geomorphological, Lithological Variations and Geological Structures in the Bogor Groundwater Basin, Upper Cisadane Watershed, West Java, Indo

Abstract

In volcanic aquifer deposits, understanding the interconnectedness of hydrogeological and hydrological systems is crucial for sustainable water management. This study explores the Bogor Groundwater Basin within the Upper Cisadane Watershed, West Java, Indonesia, where volcanic activities have shaped a complex geological landscape. We develop a conceptual model elucidating these interconnected systems using geomorphological, lithological variations, and geological structures. The Bogor Groundwater Basin provides critical water resources for millions, facing threats from urbanization and land-use changes. Limited knowledge of the underlying hydrogeological framework hinders effective management. To address this gap, we present a novel conceptual model integrating diverse datasets. We map lithological units, analyzing their porosity and permeability. Structural geology analysis identifies faults and fractures influencing groundwater movement. Morphometric techniques quantify the impact of topography and drainage patterns on infiltration and connectivity. Hydrochemical facies analysis, the core of our model, reveals geochemical fingerprints associated with recharge zones, flow pathways, and potential contaminant sources. This multifaceted approach yields a spatially explicit model capturing the interplay between geological controls, hydrological processes, and geochemical evolution. Our objectives are to develop a robust conceptual model of interconnected hydrogeological and hydrological systems., quantify the influence of lithology, structures, and morphometric features on groundwater flow and recharge, identify and characterize distinct hydrochemical facies, elucidating their distribution and relationship to flow pathways, and provide a framework for sustainable groundwater management in the Bogor Basin and similar volcanic settings. This study offers valuable insights into the complex interplay between hydrogeological and hydrological systems within volcanic aquifers. Our findings provide a foundation for sustainable water management strategies in the Bogor Basin and analogous volcanic environments. The findings establish a correlation between the straightness patterns of hills and valleys, morphotectonics, the overall structural pattern, and their influence on spring characteristics and distribution. Observations on 110 springs classify them into three zones; zone 1, The laharic zone, ranging from 300 to 500 meters above sea level; zone 2, Pyroclastic deposits found at an elevation of 500–700 meters above sea level, consisting of pyroclastic breccias and tuff lapilli; zone 3, At elevations spanning 700–1100 meters in pyroclastic breccias and 1100–1500 meters in andesitic lava. The developed conceptual model not only enhances our understanding of the complex subsurface processes but also offers valuable insights for sustainable water resource utilization in volcanic terrains. The findings of this research contribute to the broader field of hydrogeology and serve as a valuable reference for similar geological settings worldwide.