胶东半岛丘陵区典型流域径流衰减态势及驱动力分析

Analysis of Funoff Decreasing Trend and Driving Force for the Typical Basin of Hilly-Area in Jiaodong Peninsula

利用大沽夹河流域1966-2004年各水文站逐年月实测水文资料,从年际、年内和年代际三个不同时间尺度,分析了近40年来大沽夹河流域径流变化趋势及其影响因素。结果表明,近40年来,在不同时间尺度上,大沽夹河流域径流均呈明显衰减态势。由年际变化知,流域年径流量自20世纪70年代初至80年代中期下降明显,70年代年径流距平值均大于0,变化范围为0．58-2．81亿m3,平均距平值高达1．73亿m3,80年代以后,距平值基本处于0线以下,为径流低值期。年内各季变化趋势和年际变化基本相似。从年代际变化看,20世纪80年代径流衰减幅度最大,年平均径流量仅为70年代的23．24％,多年平均的53．91％,表明近20年来大沽夹河流域径流锐减。降水、气温与径流量的统计、相关分析表明,流域径流量随降水减少和气温上升呈明显下降趋势,两者与径流量的相关系数分别为0．8861和-0．3842,分别在α=0．001和α= 0．05时达显著相关。此外,水利工程取用水量(蓄、引、提河道来水)也是导致大沽夹流域径流量衰减的主要因素。

Based on the long-term data （1996-2004） from the various hydrometry stations in the Dagujia River Basin, this paper analyzed the runoff variation trend and impact factors in recent 40 years on different time scales. The results show that the runoff in the Dagujia River Basin obviously decreased in recent 40 years. As for the inter-annual variability, the runoff decreased clearly from the beginning of 1970s to the middle of 1980s. In the 1970s, the anomaly of runoff was more than zero （range： 0.58-2.81× 10^8m^3）, and the average anomaly was higher to 1.73×10^8m^3. After 1980s, the anomaly was less than zero. The seasonal change trend was similar to the inter-annual variability. As for the inter-decadal change, the runoff sharply decreased in the 1980s, the mean annual runoff was merely 53.91% of long term mean runoff and 23.24% of 1970s＇, which means that the runoff in the Dagujia River declined sharply in recent 20 years. The statistic and correlation analysis of precipitation, temperature and runoff showed that the runoff descreased clearly with reduction of precipitation and rise of temperature. The correlation coefficient between precipitation and runoff was 0.8861 and that between temperature and runoff was -0.3842. Both of them separately reached significant correlation at α=0.01 and α=0.05. Otherwise, water demand from water structures is another main factor that caused the runoff decline of the Dagujia River Basin.