DETERMINATION OF HYDROGEOLOGICAL ENVIRONMENTS (GROUNDWATER ENVIRONMENTS) OF ISTANBUL PROVINCE FOR DRINKING AND USAGE WATER SUPPLY AFTER EARTHQUAKE AND THEIR RELATIONSHIP WITH GATHERING-SHELTERING-TENT AREAS

It is an undisputed fact accepted by almost everyone that Istanbul's need for all kinds of water will always be the most important agenda item in the future as it is today, and that negative climate change conditions are affecting the availability of very reliable water both in Istanbul province and its surroundings today, considering the future population potential.

In general; although groundwater is used in a lower amount compared to surface water, it offers the opportunity to be used in places where mains water cannot be taken, as it is almost completely of drinking water quality as long as it is not polluted and does not require any purification process. However, the fact that drinking water has almost become unavailable as a result of unconscious production and use necessitates a much more special and unique perspective on Istanbul's underground waters, which are of great strategic importance in terms of drinking water supply, especially when considered in a disaster-focused context.

It should not be overlooked that Istanbul's waters will be needed to supply drinking water that will be needed after an inevitable and destructive earthquake, and that groundwater should be used in particular. Another reality is that the existence, usability, protection and protection from local disadvantages of Istanbul's underground waters should be investigated, evaluated and their sustainability should be ensured in order to create a more secure tomorrow against the negative effects of global warming on water resources.

Based on these approaches, within the scope of the "Earthquake Mobilization Plan" shared by Istanbul Metropolitan Municipality Mayor Mr. Ekrem İMAMOĞLU with 16 million Istanbulites, the work of reducing earthquake risk should be; It is aimed to determine the underground water reserves related to the Hydrogeology of the Istanbul Provincial Area, which is an important work item especially in pre-earthquake risk reduction steps and post-earthquake emergency management, in terms of drinking and utility water, by emphasizing the idea that it should be addressed with a holistic strategy that is all-in-one, multi-disciplinary, and guided by science and reason, and to determine the road map to be followed after this determination stage, to evaluate the underground water reserves detected as an important option in case the mains water and other waters are insufficient for the use of the people of Istanbul after the earthquake, to associate them with earthquake gathering-shelter areas, and to create an action plan for the next steps.

With this aim, firstly, the different permeability qualities (geohydraulic environments) characterized by the existence, size and environmental distribution prevalence of all kinds of void volumes of the existing lithostratigraphic units mapped in detail for the supply of drinking and utility water after the earthquake were redefined and mapped throughout the province, and then, based on the spatial sequences between the geohydraulic environments, the “Istanbul Provincial Area Hydrogeological Environments (Groundwater Environments) Determination Project” report was prepared and in line with this report, the “Istanbul Provincial Area Hydrogeological Environments Report and Maps” were prepared. Based on this study, the “Usability of Groundwater and Spring Water for Drinking/Useful Water in Post-Earthquake Gathering-Shelter-Tent Areas” study was also prepared, especially for the supply of vital water, especially drinking water from groundwater or spring water. association with assembly-shelter-tent areas will be made and action plans will be created in this regard. In addition, with the contributions of Hamidiye AŞ, the “Potential of Spring Water and Groundwater Operations of Istanbul Province Area” project has been completed and will be used to serve the said purpose.

The said reports have been completed and will be made available for access in the coming days.