EVALUATION of INTENSITY-DURATION-FREQUENCY CURVES of MAXIMUM RAINFALL in TURKEY
Project no. 23617 · Status: Kapanmış (Yayın bekleniyor) · 2022
Summary
<p>This thesis presents the derivation of rainfall intensity-duration-frequency (IDF) curves for Turkey, which are used as a basic tool in many engineering applications such as hydrological and meteorological studies; design of water structures such as dams, bridges, designing of rainwater drainage projects; flood risk analysis; and assessment of climate change effects. Current studies on the derivation of IDF curves are generally limited to local or regional scales in Turkey. However, since it is thought that the structure of extreme events, especially under the effect of climate change caused by global warming, has changed, IDF curves based on long-term data of maximum rainfall should be updated more frequently than in the past. Another deficiency is that both government institutions (General Directorate of State Hydraulic Works, Turkish State Meteorological Service, etc.) and most academic studies base their approaches on the assumption that the data is stationary when obtaining IDF curves.</p><p>For these reasons, within the scope of the thesis, maximum rainfall data in 14 time series with rainfall durations ranging from 5 minutes to 24 hours recorded at 107 meteorological stations representing different climate and geographical regions of Turkey were first examined in terms of trend, normality, randomness and internal dependency structure. Then, stationary frequency analysis was performed on 74 stations and non-stationary frequency analysis was performed on 33 stations with these data. In obtaining the estimations for certain return periods, models based on Generalized Extreme Value (GEV) probability distribution, which has been shown to successfully represent the maximum rainfall in Turkey, were used. As the thesis output, estimations for certain return periods, IDF curves based on these estimates and precipitation intensity maps were presented.</p>