Browsing by Author "Ülker, Duygu"

Now showing 1 - 2 of 2

Citation Count: 4
Assessment and Simulation of Water Transfer for the Megacity Istanbul
(Bellwether Publishing, Ltd., 2021) Burak, Selim; Bilge, Ayşe Hümeyra; Ülker, Duygu
The population of Istanbul increased from three to fifteen million from 1970 to 2018. The city, which has no perennial fresh water resources within its metropolitan boundaries, has long imported water from other basins. In this study, the performance of a reservoir system fed by surface runoff and inter-basin water transfer is investigated and applied. Simulations are run for water demand estimates and with Gamma-distributed realizations of monthly precipitation, based on 105-year temperature and precipitation data. The research shows that after 2060, existing and transferred water alone will not be sufficient to meet demand and it is expected that the megacity Istanbul will be on a path towards water crisis after this date, if not before. It is concluded that it is vital to adopt a more diversified water supply and demand management portfolio with extensive Integrated Water Resources Management (IWRM) measures for “Water Sensitive Cities”. Strategies for reliable system operation that take foreseeable environmental problems into account are proposed.
Citation Count: 7
COMPUTATION OF MONTHLY RUNOFF COEFFICIENTS FOR ISTANBUL
(VINCA INST NUCLEAR SCI, 2021) Bilge, Ayşe Hümeyra; Ülker, Duygu; Burak, Selman
Water demand for Istanbul is supplied both by impounded reservoirs located within its provincial boundaries and by water transfer from Western and Eastern regions in peripheral areas, located in South-West Black Sea region. The runoff coefficient defined as the ratio of the streamflow to the precipitation, plays a key role in the calculation of the surface water yield of water catchment areas. In this paper, we present the computation of monthly runoff coefficients for an accurate estimation of the yield of the catchment areas. We obtain statistical parameters for monthly temperatures and precipitation, based on 105-year data recorded at Istanbul Kandilli Observatory, modeled as Gaussian and Rayleigh distributed random variables, respectively. We run simulations to predict temperatures and precipitation over a horizon extending to 2100. We apply Turc's formula and Thornthwaite method to obtain monthly runoff coefficients based on long-term data. The results are compared and discussed with the findings of previous researches.