Estimating intensity-duration-frequency curves under changing climate conditions

Developing world conditions bring along technological advances. While these advances bring many benefits in many areas, the harm to nature is increasing in parallel in many areas. The ever-increasing population growth brings with it an uncontrollable consumption approach and harms the nature even more. Along with all these situations, the climate conditions in the world have been seriously affected by the increase in greenhouse gases and other harmful gases, and the situation has arisen to face climate change on a global scale. With the resulting climate change, extreme temperature increases, heavy and continuous rains, flood situations caused by heavy rains, loss of life and property with floods, serious water losses due to evaporation in the world's water bodies are seen. This climate change has been of great importance in the global sense, and many studies have begun to be carried out in order to prevent the destruction of climate change and to take various measures in this area. Intensity time recurrence curves (IDF) are of great importance in various structures such as water structures, flood prevention structures, drainage systems, which are necessary to prevent the harmful effects of climate change. In these curves, precipitation data of 5, 10, 15, 30 minutes and 1, 2, 6, 12, 24 hours and 2, 10, 25, 50, 100 annual recurrence periods are available. With the help of these curves, flood prevention structures, various water structures, drainage systems can be designed and improved more conveniently and safely. Intensity duration recurrence curves are generally formed with the help of historically observed and recorded data. The necessary data for the formation of these curves are obtained, the maximum precipitation data for the periods are found among the data, the most appropriate probability distribution method is selected, and the precipitation is arranged according to the recurrence periods with the help of this method, and a curve is created. Considering the climate change, the current IDF curves need to be updated because the changing climatic conditions and precipitation conditions can also show very serious differences. It would not be right to interpret these differences with IDFs formed on historical data. As a solution to this situation, various climate models have been created and climate scenarios have been produced. With the help of these models, IDF curves can be updated and more reliable curves can be obtained. In this study, it has been tried to make future precipitation forecasts for Muğla, Ordu and Diyarbakır with the global climate model data, to make the results suitable for interpretation throughout Turkey due to the Mediterranean, Black Sea and harsh continental climates of the selected cities, and to be more prepared for the problems arising from climate change. It is aimed to bring a situation to a situation and to be prepared for possible bad consequences. Three global models named HADGEM2-ES, GFDL-ESM2M and MPI-MSE-MR with RCP 4.5 and RCP 8.5 scenarios were used in the study. The process started with the historical data and model data of the cities obtained from the General Directorate of Meteorology.With the help of the Equidistance Quantile Matching Method, both historical data and global model data were parsed into 5, 10, 15, 30 min and 1, 2, 6, 12, 24 hour data. By choosing the maximum data of the separated data, the precipitation values of 2, 10, 25, 50, 100 year recurrence periods were found by means of Gumbel probability distribution method and IDF curves were created. Historical data and future precipitation data were compared.