Urban climate resilience and water insecurity: future scenarios of water supply and demand in Istanbul

For millennia, cities have invested in inter- and intra-regional infrastructure to transfer water from neighboring sources. This study analyzed how climate change can affect the balance of water supply and demand in the megacity of Istanbul, Turkey over the next 100 years. The Water Evaluation and Planning (WEAP) method was used to examine three long-term scenarios for water availability based on differences in water supply: 1) a continuation of current supply sources; 2) expansion of water resources based on construction of additional water infrastructure; and 3) reduction in water resources to rely on local resources only. Our findings show that extending dependence on inter-regional water supplies is not only likely to increase Istanbul's own water insecurity, but may also affect the human populations, biodiversity and economies of neighboring cities, representing an unsustainable solution that can only exacerbate regional water insecurity in the long run.