Statistical Assessment of Rainfall Characteristics in Upper Blue Nile Basin over the Period from 1953 to 2014

Water

Wael Elham Mahmod¹  Manabu Fujii²  Amr Eltawil³  Mona G. Ibrahim³  Abeer Samy³  Waled Daoud⁴ 

[1]Civil Engineering Department, Faculty of Engineering, Assiut University, Assiut 71515, Egypt

[2]Department of Civil and Environmental Engineering, School of Environment and Society, Tokyo Institute of Technology, Tokyo 152-8552, Japan

[3]Environmental Engineering Department, School of Energy Resources, Environmental and Chemical & Petrochemical Engineering, Egypt-Japan University of Science and Technology, E-JUST, Alexandria 21934, Egypt

[4]Faculty of Engineering, Benha University, Cairo 11629, Egypt

关键词: Coefficient of Variation;    Precipitation Concentration Index;    Mann–Kendall trend analysis;    Sen’s slope estimator;    Pettitt Test;    Upper Blue Nile basin;   

DOI  :  10.3390/w11030468

来源: DOAJ

【 摘 要 】

Investigating the trends of hydro-meteorological variables and checking its variability are of great importance for water resources management and development in the River Nile basin. The present study aimed to analyze the rainfall variability and trends in the Upper Blue Nile Basin (UBNB) over a period from 1953 to 2014. Variability analysis showed that the basin has been suffering from variable rainfall events causing severe droughts and floods over different years. According to precipitation concentration index calculations, the basin had irregular and strong irregular rainfall distribution over the annual and dry seasons, while the basin had a uniform and moderate rainfall distribution during the rainy season and small rainy season. For the total annual rainfall, Mann–Kendall test indicated that, for the eastern central part of the basin, a significant increasing trend of 12.85 mm/year occurred over the studied period, while, for the southwestern part of the basin, a significant decrease of 17.78 mm/year occurred. For the rainy season, a significant increasing trend over the northeastern and eastern central parts of the basin with the magnitude of 3.330–12.625 mm/year occurred. Trend analysis was applied on the monthly averaged rainfall over the whole basin and revealed that July and August are the most contributors of rainfall to the basin with 23.32% and 22.65%. Changing point assessment revealed that at Lake Tana outlet there is a decreasing of the rainfall of 17.7% after 1977 that matched with the trend analysis results. The data and results contained herein provide updated information about the current situation in the UBNB. The results can be used to predict future precipitation and estimate the uncertainty in future precipitation prediction models.

【 授权许可】

Unknown