Variability and change of precipitation and flood discharge in a Japanese river basin
Variability and change of precipitation and flood discharge in a Japanese river basin
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DOI：
10.1016/j.ejrh.2018.12.003
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Makoto Higashino;H. Stefan
中科院分区：
文献类型：
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作者：
Makoto Higashino;H. Stefan
研究区域位于日本西南部九州岛的Banjo河流域。研究重点本研究的重点是在小而陡峭的流域中，局部和/或大尺度气候变化对河流流量的影响。研究了极端和平均降水量与河川（洪水）径流量的变化、趋势、相关性和变化，提出了新的水文见解在日本小而陡的流域，最大年洪水径流量发生在雨季，与日最大降水量在时间尺度上有很好的相关性。从1960年到2015年，该流域记录的日流量和降水量数据的相关系数R2= 0.72。在数据分析中还发现，最大和平均年流量的变化很大，日极端降水量和河流（洪水）流量呈显著上升趋势。年最大洪水从1960年的330 m3/s平均每年增加5.98 m3/s;观测到的最大年降水量趋势（每年1.1 mm/天）充分说明了这一增加。在年时间尺度上，最大降水量和最大洪水流量与太平洋的厄尔尼诺-南方涛动（ENSO）同步大幅增加。时间频率分析表明，班卓河流域年最大洪水流量的周期分量自21世纪初以来已变得显著，其周期约为6 ~ 8年。流量超过100、200、300、400和500 m3/s的天数有所增加，这对防洪规划很重要。
Study regionThe Banjo River basin on Kyushu Island in the southwest of Japan.Study focusThis study focuses on the impact of local and/or large scale climate change on the river flow in the small and steep river basin. The variability, trend, correlation and change of extreme and mean precipitation and river (flood) runoff are investigated.New hydrological insightsIn the small and steep river basins of Japan, the maximum annual flood runoff which occurs in the wet season, is well correlated with maximum precipitation on a daily time scale. Daily flow and precipitation data recorded in the basin from 1960 to 2015, have a correlation coefficient R2= 0.72. A high variability of the maximum and mean annual flows, and significant rising trends in daily extreme precipitation and river (flood) flows were also found in the data analysis. The maximum annual flood has increased on average by 5.98 m3/s per year from 330 m3/s in 1960; this increase is fully accounted for by the trend in observed maximum annual precipitation which is 1.1 mm/day per year. On an annual timescale maximum precipitation and maximum flood discharges have become substantially higher in phase with the ENSO (El Nino-Southern Oscillation) in the Pacific Ocean. Time frequency analyses revealed that a periodic component of the annual maximum flood flow in the Banjo River basin with a period of about 6 to 8 years has become significant since the beginning of the 21 st century. The number of days with more than 100, 200, 300, 400 and 500 m3/s flows has increased, which is important for flood control planning.