胶东半岛大沽河流域径流变化特征

大沽河是胶东半岛最大的河流，被称为青岛市的“母亲河”，近年来受气候变化与人类活动的共同影响，河川径流量急剧减少，河道断流形势严峻。基于1964-2008年大沽河3个水文站点（南村、产芝水库和尹府水库）的径流资料以及青岛气象站点的气象资料，初步探讨了大沽河流域径流的年际年内特征、变化趋势及其原因。结果表明：大沽河年径流存在明显的年代际特征，45 a间有一定下降趋势，特别是20世纪80年代以来，南村站河道常出现全年断流现象；3个水文站均于60年代初发生了突变，而且尹府水库站的年径流还存在显著的准4 a的变化周期；南村站径流的季节特征及变化趋势均比较显著，年径流量的89.8%集中在汛期，汛期径流量及各月径流（除8-9月）在45 a间均呈显著下降趋势，非汛期径流变化趋势虽不明显，但其径流量自80年代以来大多年份为0；相对而言，产芝水库和尹府水库站径流的季节差异及趋势相对较小；由基准期（1964-1980年）到变化期（1981-2008年），降水变化与人类活动分别导致年径流量减少的比例为52.38%和47.62%，说明两者对径流的减少作用均比较显著，而且在全球气候变化的背景下，人类活动进一步加剧了径流的减少，并促使大沽河演变为季节性河流。

Variation of Runoff Volume in the Dagu River Basin in the Jiaodong Peninsula

The Dagu River is the largest river in the Jiaodong Peninsula, and it is called as the mother river of Qingdao City. Runoff volume of the river has been sharply reduced since recent decades, and the drying up of the river course has occurred frequently, which have seriously threatened the economic development and ecosystems. In this paper, the variation of annual and seasonal runoff volumes and the affecting factors were analyzed based on the data of monthly runoff volumes at 3 hydrological stations of Nancun, Chanzhi Reservoir and Yinfu Reservoir as well as the annual precipitation and air temperature data observed by Qingdao Meteorological Station during the period of 1964-2008. The results showed that the annual runoff volume of the river was in a slight reduction in recent 45 years, but its decadal difference was remarkable, especially since the 1980s. The annual runoff volume at Nancun Hydrological Station became zero for many years. There was a sharp change of annual runoff volumes at the 3 hydrological stations in the early 1960s, and also a 4 year fluctuation quasi periodicity of annual runoff volume at Yinfu Reservoir Hydrological Station. Seasonally, 89.8% annual runoff volume at Nancun Hydrological Station occurred in flood season. Moreover, the runoff volume at Nancun Hydrological Station was in a notable reduction in flood season and other months except in August and September, its change was not obvious in non flood season, but the runoff volume was 0 in most years from the 1980s. Seasonal difference of runoff volume between the hydrological stations of Chanzhi Reservoir and Yinfu Reservoir was low compared with that at Nancun Hydrological Station. Compared with the annual runoff volume during the period of 1964-1980, the percentages of reduced annual runoff depth by precipitation reduction and by human activities during the period of 1981-2008 were 52.38% and 47.62% respectively, which revealed that the runoff variation was strongly affected by these two factors. Furthermore, under the background of global climate change, human activities exacerbated the reduction of runoff volume and resulted in the Dagu River to be as a seasonal river.