Modelling of groundwater flow in the Kayseri volcanic aquifer system

In this thesis, the Kayseri City Volcanic Rock Aquifer System (KVAS), which provides drinking, industrial and irrigation water of Kayseri City, was examined. Firstly in the study, in order to reveal the hydrogeological conceptual model of the volcanic rock aquifer system, the geological, hydrological and hydrogeological characteristics of the study area were defined, and in this direction, hydrogeochemical and isotope hydrology methods were used. By evaluating the data obtained from all these studies together, the input and output components of the system were defined in detail and a hydrogeological conceptual model was created. It has been revealed that the recharge of the KVAS is realized by the snow waters formed by the melting of the snow falling on Mount Erciyes, the groundwater flow from the Sarimsakli Plain and the infiltration of the surface flow into the underground. Groundwater discharge is defined as discharge to the Karasazlık Subsystem and withdrawal by wells. Then, a mathematical groundwater model was created in order to test the validity of this hydrogeological conceptual model, which expresses the recharge-storage-circulation-discharge relationship of the KVAS. Many wells have been drilled in this volcanic rock aquifer system of Kayseri City, which has a very complex hydraulic structure. However, groundwater level observations have not been made systematically, both before and after the operation, reflecting the dynamic nature of the hydrogeological system. Therefore, within the scope of this thesis, it was necessary to calibrate with the derived data in the numerical mathematical groundwater flow model that defines the KVAS. As a result, suggestions have been developed for the sustainable method of the volcanic rock aquifer system of Kayseri City by using the numerical groundwater flow model based on the hydrogeological conceptual model set forth in this thesis.