为了分析西江干流径流年际变化趋势及年内分配规律, 根据天峨、迁江、梧州三站 60 多年实测径流资料, 采用 M ann2Kendall 趋势检验法、R/ S 法、有序聚类法、滑动 T 检验法等多方法分别对径流年际变化的趋势性和突变性进 行分析; 同时, 对表征径流年内分配的各指标进行趋势性检验和未来变化趋势预测。结果表明: 三站的 M2K 统计量 Z 值分别为221 47、- 21 38 和- 11 47, Hurst 指数分别为 01 72、01 83 和 01 80, 均大于 01 5; 天峨站和迁江站的突变点均 为 2002 年, 梧州站的突变点为 1954 年和 2002 年; 西江径流 60 多年来显著减少, 且具较强的持续性; 径流年内分配 不均, 多集中在 4 月- 9 月, 占年径流的 75% 左右; 2002 年后径流年内分配显著性地趋于均匀, 集中程度和变幅亦 显著性地变小, 集中期前移 12 日左右。

In o rder to study the inter annual variatio n tr end and annual distribution o f r unoff in Xijiang Riv er, we used Mann2Ken2 dall trend test, R/ S metho d, ordered cluster method, and sliding T t est to ana lyze the variatio n trend and abrupt changes o f in2 ter annual runo ff, and we conducted trend tests and prediction of t he fut ur e chang e tr end fo r each index o f annual r unoff distribu2 tion. T he analy sis was based on the measured runo ff data of the main stream of Xijiang Riv er for o ver 60 years. The r esults show ed t hat M2K statist ic values in the t hr ee st at ions wer e - 21 47, - 21 38 and - 11 47 r espectiv ely. The H urst indexes of the three stations w er e 01 72, 01 83 and 01 80 respect ively, a ll g reater than 01 5. The abr upt chang e points at T ian'e and Qianjiang sta2 tions wer e bo th in 2002, while the abrupt change points at Wuzhou statio n w ere in 1954 and 2002. Xijiang Riv er runoff has sig2 nificantly declined over the past 60 y ea rs w ith a stro ng co nt inuit y. T he annual distributio n of runoff w as unev en. The r uno ff con2 centrated during April to September, which accounted for about 75% o f the annual runoff. After 2002, the annual distributio n of runo ff show ed a r emarkable t endency towar ds unifo rmit y; the deg ree o f concent ratio n and variatio n amplitude bot h sig nificant ly decreased, and the concentr at ion perio d mo ved about 12 days forwar d.

国家重点研发计划( 2017YFC0405900) ; 国家自然科学基金( 51469002; 51009029) ; 广西重点研发项目( 桂科 AB16380284) ; 广西 自然科学基金项目( 2015GXNS FBA139218)