| 频率/% | 不同世纪天然径流量/亿m3 | 突变年份前后天然径流量/亿m3 | |||||||
| 1470~1500 | 1501~1600 | 1601~1700 | 1701~1800 | 1801~1900 | 1901~2017 | 1470~1864 | 1865~1989 | 1990~2017 | |
| 5 | 582.2 | 626.8 | 652.2 | 684.0 | 867.0 | 680.0 | 684.0 | 516.2 | 372.0 |
| 减少百分率 | - | −7.7 | −4.1 | −4.9 | −26.8 | 21.6 | - | 24.5 | 38.8 |
| 50 | 469.2 | 522.9 | 514.2 | 511.1 | 512.4 | 476.0 | 680.0 | 478.0 | 295.0 |
| 减少百分率 | - | −11.4 | 1.7 | 0.6 | −0.3 | 7.1 | - | 29.7 | 62.0 |
| 95 | 431.5 | 386.1 | 411.1 | 365.0 | 290.0 | 315.4 | 544.4 | 415.3 | 292.6 |
| 减少百分率 | - | 10.5 | −6.5 | 11.2 | 20.5 | −8.8 | - | 23.7 | 41.9 |