Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
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Article Citation - WoS: 2Citation - Scopus: 2Assessment of Future Water Demand in a Semiarid Region of Turkey: a Case Study of Tahtali–seferihisar Basin(Springer, 2023) Karahan, S. M.; Elçi, ŞebnemWater is a vital resource for society and nature, and its scarcity has consequences in all aspects of existence. Today, issues including the inability to preserve the status of existing water resources and excessive water withdrawal are causing the amount of water to diminish day by day. Furthermore, factors such as urbanization and industrialization, population growth, water quality degradation owing to agricultural pesticides, and climate change, all have a negative impact on water supplies. A basin-based water management analysis was carried out in this study by applying the "Integrated Water Resources Management" strategy to the Tahtalı–Seferihisar sub-basin in Turkey, where water stress is expected in the future. Using the WEAP (Water Evaluation and Planning System) model, the hydrological (precipitation, flow, evaporation) data of important water resources for the basin and Izmir (Tahtalı, Seferihisar, Ürkmez, and Kavakdere Dams) were used to predict the availability of water resources in the future, and several possible scenarios for water demands/supplies were analyzed. The water budget balances projected in 2050 have been calculated by considering six different scenarios: Reference Scenario, Report Consumption Scenario, Optimistic Case Scenario, Pessimistic Case Scenario, Return Flow Scenario, and Various Forecast Scenario. The water balances that can be obtained in each scenario under various situations were computed and compared. For all considered scenarios, unmet water demand in the basin is found to be significant (157.52 hm3 in the Optimistic Case Scenario and 373.16 hm3 in the Pessimistic Case Scenario).Article Citation - WoS: 2Citation - Scopus: 2Observational and Numerical Methods for Quantifying and Modeling of Turbulence in a Stratified Reservoir(Isfahan University of Technology, 2016) Elçi, Şebnem; Ekmekçi, Hüseyin BurakThe interplay between stratification and shear in lakes controls the vertical mixing, which is the mostimportant mechanism affecting the transport of heat, salt, momentum and suspended and dissolvedsubstances. This study attempts to quantify and characterize the turbulence from direct measurementsconducted in a reservoir. A 3D numerical model is used to investigate the water column hydrodynamics forthe duration of measurements and the performance of various turbulence models used in the CFD model areinvestigated via simulation of mixing in the reservoir. The drawdown curves produced by the turbulencemodels are formulized through linear equations. Although, use of different turbulence models do not havesignificant effects on the flow hydrodynamics away from the intake structure; significant effects especially onturbulence kinetic energy production are observed at the orifice. Therefore, for simulation of withdrawalflow, either use of shear stress transport (SST) k-omega models solving equations all the way to the wall or kepsilonmodels with the nonequilibrium wall function is recommended to account for the changes in thepressure gradient. In this study, the methods using quantified turbulent characteristics of the flow toreformulate the Stokes' settling velocity to be applied in turbulent flows are also investigated. An approach topredict setting velocity in turbulent flows that utilizes acoustic Doppler instruments for quantification ofturbulent characteristics is presented. Modification of the Stokes' settling velocity with thenondimensionalized turbulent kinetic energy production profiles lead better results than other turbulencecharacteristics (buoyancy flux and by Richardson number flux) widely used in characterizing turbulentmixing.