Implementation of a flood management system for Nicosia


Thesis Type: Doctorate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Civil Engineering, Turkey

Approval Date: 2018

Student: HASAN ZAİFOĞLU

Supervisor: ALİ MELİH YANMAZ

Abstract:

The implementation of effective flood management particularly in ungauged basins requires regional frequency analysis (RFA) to determine the occurrence probabilities of extreme precipitation events. In this context, the quality control and homogeneity analysis of daily precipitation series of 37 stations in Northern Cyprus are carried out and trend analyses are employed to assess the variability of extreme precipitation indices. The increasing trends especially in winter period are dominated the northern part of the island. Then, identification of homogeneous regions is performed by utilizing the time series clustering approaches as a new perspective in RFA and the quantile estimates for different return periods are obtained. The flood hydrographs generated from the SCS Unit Hydrograph approach are provided to the outlet of Kanlıköy and Gönyeli ponds which are the boundary conditions for the river model. Moreover, 1D model MIKE 11 for the Kanlıdere River’s tributaries is developed to simulate the flow in main channel. Besides, the flow depths, velocities, and flood inundation extent on floodplain is detected by 2D MIKE 21 model. MIKE FLOOD coupling of MIKE 11 and MIKE 21 is used to simulate the flood event in 2010 and the flood inundation maps are generated based on the different scenarios. Flood mitigation alternatives, such as dredging and increasing crest elevations of dam and spillway for Gönyeli Pond, and implementation of a new upstream detention facility for Kanlıköy Pond were proposed. The proposed structural measure shows that Nicosia can be protected from flooding up to approximately 500-year return period.