This dissertation develops an integrated hydrological and hydrogeological modeling framework for assessing groundwater–surface water interactions and evaluating sustainable water management strategies under conditions of long-term anthropogenic stress.

The research combines the Soil and Water Assessment Tool (SWAT) and MODFLOW models through a sequential integrated methodology that enables the simulation of surface water processes, groundwater flow dynamics, recharge variability, and stream–aquifer interactions within a unified basin-scale framework. The methodological approach incorporates multi-source climatic, hydrological, hydrogeological, and land-use datasets to evaluate both spatial and temporal changes in water availability and storage. In addition, hierarchical clustering techniques are included to reduce spatial complexity and improve the interpretation of hydrological behaviour across heterogeneous sub-basins.

A central contribution of this dissertation is the integration of nature-based solutions into the modeling framework to evaluate recharge-enhancement strategies such as terracing and managed aquifer recharge through infiltration ponds. Scenario-based simulations demonstrate how these interventions influence runoff generation, groundwater recharge, groundwater storage recovery, and hydrological resilience.

The dissertation contributes a transferable and scalable methodology for integrated water resources assessment in highly stressed and data-limited regions. By linking hydrological and hydrogeological processes within a single analytical framework, this research advances the scientific understanding of integrated water modelling and provides practical tools to support sustainable planning, long-term resource management, and climate adaptation strategies in overexploited basins worldwide.