Understanding flood seasonality and flood regime shift in the Congo River Basin
Understanding flood seasonality and flood regime shift in the Congo River Basin
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DOI：
10.1080/02626667.2022.2083966
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发表时间：
2022-06
影响因子：
3.5
通讯作者：
G. Bola;R. Tshimanga;J. Neal;M. Trigg;Laurence Hawker;V. Lukanda;P. Bates
中科院分区：
文献类型：
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作者：
G. Bola;R. Tshimanga;J. Neal;M. Trigg;Laurence Hawker;V. Lukanda;P. Bates
摘要在刚果盆地(CB)调查较少的地区，通过基于块极大值和峰值超过阈值(POT)序列的相对频率、聚类分析、方向统计和非重叠块方法，建立了洪水季节性和汛情变化。所有测站都观测到了两个月的严重洪涝灾害。洪水的空间分布呈现北西北、南东南、西东三种类型。结果表明，北部和南部的洪水分布是一致的，而沿赤道从西到东的大带上的洪水分布是双峰的。洪水指数的时滞表明，汛情不是平稳的。此外，时间序列显示出洪水高发的时期，20世纪60年代和70年代初的盆栽频率和幅度比其他任何时期都要高。
ABSTRACT In the sparsely investigated region of the Congo Basin (CB), flood seasonality and flood regime shift are established through relative frequency, cluster analysis, directional statistics, and non-overlapping block methods based on block maxima and peak over threshold (POT) series. Two months of significantly rich floods are observed at all gauging stations. The spatial distribution of floods presents three patterns: the north and northwest pattern, south and southeast pattern, and west/east pattern. It is observed that unimodal flood distribution is coherent in the northern and southern parts, as opposed to the bimodal flood distribution observed along the large band of the Equator from west to east of the basin. The time lag of flood indices suggests that the flood regime is not stationary. In addition, the time series show periods of high flooding, with POT frequencies and amplitudes higher during the 1960s and early 1970s than any other time period.