Statistical Assessment of Rainfall Characteristics in Upper Blue Nile Basin over the Period from 1953 to 2014
Statistical Assessment of Rainfall Characteristics in Upper Blue Nile Basin over the Period from 1953 to 2014
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DOI：
10.3390/w11030468
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发表时间：
2019-03
期刊：
影响因子：
3.4
通讯作者：
Abeer Samy;Mona G. Ibrahim;W. Mahmod;M. Fujii;A. Eltawil;Waled Daoud
中科院分区：
文献类型：
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作者：
Abeer Samy;Mona G. Ibrahim;W. Mahmod;M. Fujii;A. Eltawil;Waled Daoud
研究尼罗河流域水文气象变量的变化趋势，检验其变异性，对于尼罗河流域水资源的管理和开发具有重要意义。本研究旨在分析1953-2014年间青尼罗河上游流域(UBNB)的降雨变率和趋势。变异性分析表明，该流域在不同年份一直遭受不同降雨事件的影响，导致严重的干旱和洪水。根据降水集中指数计算，流域年、枯季雨量分布不规则且较强，雨季和小雨季雨量分布均匀、中等。对于年总降雨量，Mann-Kendall检验表明，在研究期间，盆地中东部出现了12.85 mm/年的显著增加趋势，而盆地西南部则显著减少了17.78 mm/年。在雨季，盆地东北部和东部中部出现了明显的增加趋势，幅度为3.330-12.625 mm/年。对全流域月平均降雨量进行趋势分析，结果表明，7、8月份对流域降雨量的贡献率最大，分别为23.32%和22.65%。转点评估表明，1977年以后塔纳湖出海口降雨量减少了17.7%，与趋势分析结果相吻合。本文件所载数据和结果提供了关于UBNB当前情况的最新信息。预测结果可用于未来降水预报和未来降水预报模型的不确定性估计。
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.