Future short-term estimation of flowrate of the Euphrates river catchment located in Al-Najaf Governorate, Iraq through using weather data and statistical downscaling model

Abstract

Abstract The issue of global warming has negatively affected the global climate, which caused a decrease in the amount of precipitation and a significant increase in temperatures and evaporation rates. Iraq suffers from poor rainfall, which exacerbates the problem of declining water levels in rivers and the drying up of some tributaries. The Euphrates river, which passes through the eastern side of the Al-Najaf Governorate, is the case study in the current research. A statistical downscaling model is created for rainfall data from 2010 to 2020 with the aim of predicting the future precipitation biennially from 2022 to 2028. The model is calibrated and reflects close results with observations with high accuracy and reliability. The future precipitation levels are transformed after multiplying these levels by the total surface areas of the Euphrates river and its tributaries, and the value of future flowrates to be added to the Euphrates river is estimated. The results showed that the Euphrates river will receive a flowrate of 1,535,945 m3 in 2026, which is the highest value when compared with the values of flowrate for the years 2022, 2024, and 2028, which are estimated at 1,475,072, 1,456,037, and 1,378,403 m3, respectively.