沂河流域暴雨径流变化特征研究

目的]探究气候因素驱动下沂河流域暴雨径流的变化规律，阐释流域暴雨径流的影响因素，为深入理解流域水文响应过程和水资源管理提供科学参考。方法]利用改进后的Lyne-Hollick数字滤波法估算了沂河流域的暴雨径流量，通过水文信号方法与皮尔逊相关系数法，定量分析沂河流域暴雨径流的变化特征及影响因素。结果](1) 1975—2000年，流域年均暴雨径流指数SFI呈缓慢下降趋势(R²=0.37,p<0.01),年际SFI下降率0.048/10 a,暴雨径流占河川径流比重下降；(2)年均暴雨径流量呈波动增加趋势(R²=0.04,p=0.35),于1998年达到研究时段峰值；(3)暴雨径流量年内季节分配差异显著，年内暴雨径流量峰值出现在7—9月，夏季暴雨径流Q₍s(sf))与冬季暴雨径流Q₍w(sf))差异较大，高暴雨径流变化指数Q_HV、暴雨径流变差系数C₍V(sf))总体呈上升趋势，低暴雨径流量变化指数Q_LV呈下降趋势；(4) 198...

Investigating Stormflow Variation Characteristics in the Yihe River Basin

Objective] The stormflow variation characteristics under climate change in the Yihe River Basin were explored, and the controlling factors were unraveled, which would provide a scientific reference for hydrological responses and water resources management at the basin scale. Methods] An improved Lyne-Hollick digital filter method was used to estimate the stormflow in the Yihe River basin. Hydrological signatures and correlation coefficient methods were used to quantitatively analyze the variation trends and influencing factors of the stormflow. Results](1)From 1975 to 2000, the stormflow index(SFI, total stormflow to total streamflow)showed a decreasing trend(R²=0.37, p<0.01), the proportion of stormflow had decreased.(2)The stormflow showed a fluctuating and rising variation trend(R²=0.04, p=0.35), especially in the high-stormflow part.(3)The seasonal distribution of stormflow was uneven, and higher values occurred from July to September, the average summer stormflow 〔Q_s(sf)〕 also revealed a large difference to the average winter stormflow 〔Q_w(sf)〕, and the variation index of high stormflow(Q_HV)and uneven coefficient 〔C_V(sf)〕 showed a significant increasing trend, while the variation index of low stormflow(Q_LV)generally showed a decreasing trend.(4)From 1981 to 2000, a strong negative correlation was detected between temperature and SFI, sunshine duration and solar radiation were the main factors affecting SFI(R=0.63 and 0.57, p=0.01), and were also a negative correlation between temperature and other stormflow signatures. There was a strong positive correlation between rainfall and annual mean stormflow Q_m(sf), 95%(95th)as well as 99%(99th)percentiles stormflow(Q_sf95 and Q_sf99, with R=0.87, 0.84 and 0.86, respectively, p<0.01). Conclusion] There was an increasing trend of stormflow with a relative larger seasonal variation. The precipitation is the main controlling factor influencing the stormflow variability. In future, it is hopeful to chase a deep understanding of stormflow characteristics with multiple scale-based approaches.