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基于石门水文站实测日径流数据和流域气象资料,运用平滑最小值法和递归数字滤波法对呼图壁河流量过程进行了基流分割研究。在不同的时间尺度上探讨了呼图壁河年均基流量和基流指数(BFI)的变化特征,以及不同水平年基流量与BFI的变化特征,并按照不同水平年份的划分从气温和降水两方面剖析影响基流变化的因素。结果表明:研究区内平滑最小值法优于递归数字滤波法。呼图壁河基流量的年内分布表现为单峰型,7月达到最大值,BFI先减小后增加,5月最小,枯水期BFI接近1。呼图壁河年基流量呈现为增加的趋势,多年平均基流量为3.67×108 m3,多年平均BFI为0.78,呈递减趋势。枯水年份的平均BFI为0.78,平水年为0.76,丰水年为0.74。春秋两季气温和降水对呼图壁河基流量的影响最为显著,不同的水平年份相关系数也存在一定差异。各年份气温对春秋两季基流量的影响均大于降水,说明气温是呼图壁河基流变化的关键性因素。
Based on the measured daily runoff data and watershed meteorological data of Shimen Hydrological Station, the base flow segmentation of the Hutubiao river flow process was studied using the method of smoothing minimum and recursive digital filtering. The characteristics of annual base flow and base flow index (BFI) of Hutubi River at different time scales were discussed, and the characteristics of base flow and BFI at different levels were discussed. According to the different levels of year, Analysis of two factors affecting the base flow changes. The results show that the smoothing minimum method in the study area is superior to the recursive digital filtering method. The distribution of Hutubi riverbed flow during the year showed a unimodal distribution, reaching its maximum in July, decreasing first and then increasing, while BFI in May was the lowest and BFI in dry season approaching one. The annual base flow in Hutubi River presented a trend of increase with a multi-year average base flow of 3.67 × 108 m3 and a multi-year average BFI of 0.78, showing a decreasing trend. The average BFI for low water years was 0.78, for flat water years 0.76 and for wet years 0.74. The influence of temperature and precipitation in spring and autumn on the Hutubi riverbed flow was the most significant, and there were some differences in the correlation coefficients of different years. The influence of temperature on the base flow in spring and autumn is more than that in precipitation in each year, which shows that temperature is the key factor of base flow change in Hutubi River.