变化环境下近60年西江流域径流时空演变特征

气候变化叠加人类活动的双重影响下,西江流域的河川径流发生了不同程度的改变,重新认识和掌握变化环境下的径流时空演变规律对流域的科学管理具有重要意义。基于西江流域干支流7个控制性水文站近60年的日径流资料,综合极点对称模态分解法(ESMD)、Mann-Kendall检验、R/S分析、小波分析等方法,从年代、年、季和年内多个时间尺度对径流的时空演变特征进行分析,研究结果表明:年代尺度下,西江流域径流丰枯交替、变化悬殊,1970s与1990s径流丰沛,2010s径流偏枯,降雨影响着径流的丰枯变化,流域上、中游更易发生干旱与洪涝灾害;春、夏、秋、冬季径流振荡周期依次为2～7、15～20、28～29 a,3～5、7～10、20 a,2～3、6～8、12～15 a和3～8、12～15、20 a,均呈现年际与年代的双重周期特征,IMF1的年际振荡在径流变化中占主导地位;受降雨与水库调蓄作用的影响,年、夏、秋季径流呈下降趋势,预测下降变化具有持续性,春、冬季径流整体呈上升趋势。空间内上游的变化趋势更显著;年和季尺度径流在1980年后突变增多,尤其集中于2000—2010年间,人类活动与气候变化是造成西江...

Temporal and spatial evolution characteristics of runoff in the Xijiang River Basin in recent 60 years under the changing environment

Under the dual influence of climate change and human activities, the river runoff in the Xijiang River Basin has changed to varying degrees. It is of great significance to re-understand and master the temporal and spatial evolution law of runoff in the changing environment for the scientific management of the river basin. Based on the daily runoff data of 7 controlled hydrological stations in the main and tributaries of the Xijiang River Basin for nearly 60 years, and comprehensive extreme-point symmetric mode decomposition method (ESMD), Mann-Kendall test, R/S analysis, wavelet analysis and other methods, the temporal and spatial evolution characteristics of runoff were analyzed from multiple time scales of the inter-decadal, inter-annual, seasonal and intra-annual. The results showed that the runoff in the Xijiang River Basin alternated and varied greatly at the inter-decadal scale. The runoff was abundant in the 1970s and 1990s, and dry in the 2010s. Rainfall affected the runoff, and the upper and middle reaches of the Basin were more prone to flood and drought disasters. The oscillation periods of seasonal runoff were 2-7, 15-20, 28-29 a; 3-5, 7-10, 20 a; 2-3, 6-8, 12-15 a and 3-8, 12-15, 20 a, respectively, all of them showed double period characteristics of interannual and interdecade. The variation of runoff was mainly determined by IMF1. Affected by rainfall and reservoir regulation and storage, there are a downward trend in the annual, summer, and autumn runoff, a persistent predicted downward change, and an upward trend in the overall spring and winter runoff. The change trend in the upper reaches of the space is more significant. The annual and seasonal runoff increased abruptly after 1980, especially from 2000 to 2010. Human activities and climate change were the main reasons for the sudden change in the Xijiang River Basin. After 2000, except the tributary Liuzhou station, the annual distribution of runoff tended to be uniform, the variation range of monthly average runoff decreased, the concentration period moved forward, and the reservoir group had a significant effect by storing water during the wet season and replenishing water during the dry season. The results provide reference for the rational development, utilization and effective management of water resources in the Xijiang River basin.