无定河流域风沙滩区河道基流变化规律与驱动因素分析

为探究风沙滩区河道基流变化规律与主要驱动因素，以1954—2018年无定河流域赵石窑水文站实测水文数据和多站点的降水量数据等资料为基础，分析比较3类方法(时间步长法、数字滤波法和平滑最小值法)对无定河流域风沙滩区河道基流分割的适用性，揭示河道基流量的变化特征，量化分析引起基流量变化的驱动因素(降水、植被覆盖度和农业灌溉等)。结果表明：时间步长法中的局部最小值法对风沙滩区河道基流分割结果较其他方法更为合理，其中多年(1954—2018年)平均基流量为3.29×10⁸ m³,基流指数均值为0.71;基流量总体呈极显著下降趋势，且在1972年和2000年发生突变，其周期性变化主要由第1主周期(32年)控制；无定河流域风沙滩区河道基流变化是降水、植被覆盖度和农业灌溉等因素综合影响的结果，其中水文序列第2阶段(1973—2000年)和第3阶段(2001—2018年)与第1阶段(1954—1972年)相比，降水对基流量变化的贡献率分别为29.35%和4.52%,人类活动(植被覆盖度和农业灌溉)的贡献率分别为70.65%和95.48%,说明人类活动是其变化...

Baseflow Variation and Driving Factors in the Blown-sand Region of Wuding River Basin

In order to investigate the variation law and main driving factors of baseflow in the blown-sand region of Wuding River Basin, this study was based on the hydrological data of Zhaoshiyao hydrological station and precipitation data of several stations in the blown-sand region of Wuding River Basin from 1954 to 2018, compared the applicability of the three kinds of methods (HYSEP, Digital Filtering and BFI method) to segmentation baseflow, revealed the variation characteristics of river baseflow, analyzed the driving factors (precipitation, vegetation coverage and agricultural irrigation, etc.) which can cause changes of baseflow in this area. The results showed that the local minimum method in the HYSEP method is better than the other methods for the segmentation of channel basic flow in the blown-sand region. The average basic flow was 3.29×10⁸ m³ and the average basic flow index was 0.71 during 1954-2018. The basal flow showed a very significant decreasing trend in 1972 and 2000, and its periodic change was mainly controlled by the first main cycle (32 years). The variation of channel base flow in the blown-sand region area of the Wuding River Basin was the result of the comprehensive influence of precipitation, vegetation coverage, agricultural irrigation, etc. Compared with the first stage (1954-1972), in the second stage (1973-2000) and third stage (2001-2018) precipitation contributed 29.35% and 4.52% to the variation of baseflow, and the contribution rates of human activities (vegetation coverage and agricultural irrigation) were 70.65% and 95.48%, it indicates that human activities were the main driving factors of baseflow change. The research results can provide a basis for the rational development and utilization of water resources in blown-sand region of Wuding River Basin.