若尔盖高原径流量变化与储水量计算

Estimation of runoff change and water storage in Zoige Plateau

若尔盖高原的降水量微弱减少与蒸发量持续上升,使若尔盖高原径流量与储水量逐年降低,直接减少了若尔盖高原的湿地面积和对黄河上游径流量的补给。基于红原、若尔盖和玛曲站的气象数据和7个水文站的径流量数据(1981-2011年),并对数据序列进行插补与计算,获得若尔盖高原的径流量变化与气候因子的响应关系,进而计算储水量变化。计算结果表明:若尔盖高原向黄河年均补水(67.08±14.90)×108 m 3,并以0.48×108 m 3/a速率持续减少。降水量每减少1 mm将导致黑河与白河的年径流量分别减少0.02×108和0.05×108 m 3。蒸发量每增加1 mm将导致黑河与白河的年径流量分别减少0.12×108和0.27×108 m 3。1981-2011年若尔盖高原的年均储水量为(59.30±18.69)×108 m 3,其年均递减速率为0.49×108 m 3/a。本研究有助于认识若尔盖高原对于黄河上游水资源保障的重要性。

The precipitation in the Zoige Plateau has decreased slightly and the evaporation has continuously risen,which reduced the water storage capacity of the Zoige Plateau continuously and led to the reduction of Zoige wetland area and decreased water resources supply into the upper Yellow River.The meteorological data of Hongyuan,Zoige and Maqu Counties and the runoff of seven hydrological stations in 1981-2011 were used to interpolate to obtain the completed the data series.The response relation between runoff change and climate factors was obtained,and the change of water storage in this region was calculated.The results show that the mean annual water supply of the Zoige Plateau into the upper Yellow River was(67.08±0.149)×108 m 3,and decreased at a rate of 48×108 m 3/a.Given that the precipitation decreases 1 mm,the runoff of Black and White Rivers decreased by 0.02×108 m 3 and 0.05×108 m 3,respectively.Correspondingly,in an increase by 1 mm evaporation,the runoff of Black and White Rivers decreased by 0.12×108 m 3 and 0.27×108 m 3,respectively.The annual increase of water storage in Zoige Plateau is(59.30±0.1869)×108 m 3,annual average reduction rate is 0.49×108 m 3/a from 1981 to 2011.This study will be helpful to understand the importance of the Zoige Plateau for water resources safety in the upper Yellow River.