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.

Year1919–19691970–19791980–19891990–19992000–2011
MonthMean MeanMean changePercent changeMeanMean changePercent changeMeanMean changePercent changeMean/108 m³/sMean changePercent change

January2.36 1.21 −1.16 −48.9%1.52 −0.85 −35.8%1.06 −1.30 −55.1% 1.54−0.82 −34.8%
February2.37 1.39 −0.97 −41.1%1.61 −0.76 −32.0%1.18 −1.19 −50.2% 1.37−1.00 −42.3%
March3.28 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%
June5.09 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%
August13.74 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%
December3.10 1.63 −1.47 −47.5%1.87 −1.23 −39.6%1.01 −2.09 −67.3% 2.23−0.87 −28.0%