Analyses of rainfall trends in the Nile River Basin
Analyses of rainfall trends in the Nile River Basin
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DOI：
10.1016/j.jher.2015.09.002
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发表时间：
2016-12-01
影响因子：
2.8
通讯作者：
Willems, Patrick
中科院分区：
文献类型：
--
作者：
Onyutha, Charles;Tabari, Hossein;Willems, Patrick
分析了非洲尼罗河流域39个地点的降雨趋势。比较了长期数据和不同时间段的短期序列的降雨趋势结果。对来自一系列短期记录的趋势结果的偏倚进行了量化。进行同质性检验以评估区域基础上趋势方向的一致性。基于75-100年降雨量数据时间段的假设总体（为简单起见），记录长度每增加10%，短期趋势分析中的偏差就会减少约10%。在某些条件下，如果尊重，它是可能的趋势，在站与短期降雨量记录的基础上，在附近的站与长期记录，但在同一地区。在所有选定的站点使用相同的数据记录长度和统一的时间段，获得了改进的降雨趋势结果的区域一致性。在赤道地区，年降雨量的趋势主要是积极的和显着的水平α = 5%的7个站点中的4个。总的来说，苏丹，埃塞俄比亚和埃及，年降雨量的趋势大多是负面的，在α = 5%的32个站点中的69%显着。在39个台站中，13%的台站在α = 1%时确认了整个NRB趋势方向的异质性。这些发现对水和农业管理实践至关重要。(C)2015年国际水环境工程与研究协会亚太分部。Elsevier B. V.出版，保留所有权利。
Trends in rainfall at 39 locations of the Nile River Basin (NRB) in Africa were analyzed. Comparison was made between rainfall trend results from the long-term data and those of short-term series selected over different time periods. The bias on trend results from series of short-term records was quantified. Homogeneity test was conducted to assess the coherence of the trend directions on a regional basis. Based on an assumed population (for simplicity) of rainfall data time periods in the range 75-100 years, bias in the short-term trend analysis was noted to reduce by about 10% for every 10% increase in record length. Under some conditions if respected, it was possible to derive trends at stations with short rainfall records based on those at nearby stations with longer term records but in the same region. Using the same data record length and uniform time period at all the selected stations, an improved regional coherence of rainfall trend results was obtained. In the equatorial region, trend in annual rainfall was found mainly positive and significant at level alpha = 5% in 4 of the 7 stations. Collectively for Sudan, Ethiopia and Egypt, trends in the annual rainfall were mostly negative and significant at alpha = 5% in 69% of the 32 stations. Heterogeneity in the trend directions for the entire NRB was confirmed at alpha = 1% in 13% of the 39 stations. These findings are vital for water and agricultural management practices. (C) 2015 International Association for Hydro-environment Engineering and Research, Asia Pacific Division. Published by Elsevier B.V. All rights reserved.