Abstract
The main concern of the paper is to provide a joint combination of probability distribution function, intensity-duration-frequency curves, and innovative trend templates under the climate change impact for better assessment of water resources systems design. The main purpose is to take currently employed approach in the design of water structures where the design variable features are derived from the complete hydro-meteorological records available; an approach is proposed where the time series is divided in half and applied. The results of the two approaches are then compared for two sites, one in southern Turkey and the other in western Saudi Arabia, using daily maximum rainfall records for more than 40 years. The features of the second half of the historical data are recommended to design water engineering structures. Climate change impacts give rise to increments of 5% (15%) over the classical approach in southern Turkey (western Saudi Arabia).