Research Article
Detecting Runoff Variation of the Mainstream in Weihe River
Table 2
Monthly runoff volumes during the five subperiods (108 m3) and changes relative to baseline (1919–1969) values.
| Year | 1919–1969 | 1970–1979 | 1980–1989 | 1990–1999 | 2000–2011 | Month | Mean | Mean | Mean change | Percent change | Mean | Mean change | Percent change | Mean | Mean change | Percent change | Mean/108 m³/s | Mean change | Percent change |
| January | 2.36 | 1.21 | −1.16 | −48.9% | 1.52 | −0.85 | −35.8% | 1.06 | −1.30 | −55.1%
| 1.54 | −0.82 | −34.8% | February | 2.37 | 1.39 | −0.97 | −41.1% | 1.61 | −0.76 | −32.0% | 1.18 | −1.19 | −50.2%
| 1.37 | −1.00 | −42.3% | March | 3.28 | 1.78 | −1.50 | −45.8% | 2.04 | −1.23 | −37.6% | 2.07 | −1.21 | −36.9% | 1.50 | −1.77 | −54.1%
| April | 4.53 | 3.17 | −1.36 | −29.9% | 3.62 | −0.91 | −20.1% | 3.32 | −1.21 | −26.8% | 1.79 | −2.74 | −60.6%
| May | 5.66 | 5.26 | −0.40 | −7.0% | 5.86 | 0.20 | 3.6% | 4.12 | −1.54 | −27.1% | 2.39 | −3.26 | −57.7%
| June | 5.09 | 2.38 | −2.71 | −53.2%
| 6.25 | 1.16 | 22.9% | 4.05 | −1.04 | −20.4% | 2.33 | −2.76 | −54.2%
| July | 12.17 | 7.21 | −4.95 | −40.7% | 11.58 | −0.58 | −4.8% | 7.57 | −4.59 | −37.7% | 4.11 | −8.06 | −66.3%
| August | 13.74 | 7.37 | −6.37 | −46.3% | 13.11 | −0.63 | −4.6% | 6.64 | −7.09 | −51.6%
| 7.10 | −6.63 | −48.3% | September | 14.15 | 12.73 | −1.42 | −10.0% | 15.89 | 1.73 | 12.3% | 5.36 | −8.79 | −62.1%
| 10.58 | −3.57 | −25.3% | October | 10.73 | 10.65 | −0.08 | −0.7% | 10.67 | −0.06 | −0.6% | 4.63 | −6.11 | −56.9%
| 10.17 | −0.57 | −5.3% | November | 5.62 | 4.69 | −0.93 | −16.6% | 5.14 | −0.48 | −8.5% | 2.77 | −2.85 | −50.6%
| 4.12 | −1.50 | −26.6% | December | 3.10 | 1.63 | −1.47 | −47.5% | 1.87 | −1.23 | −39.6% | 1.01 | −2.09 | −67.3%
| 2.23 | −0.87 | −28.0% |
|
|