降水和人类活动对秃尾河流域基流的影响

基于秃尾河高家川站1956—2012 年实测日径流数据,采用递归数字滤波法进行基流分割,并对高家川基流的趋势性、持续性、多时间尺度和突变特征进行分析。最后,采用累积斜率法计算降水和人类活动对基流的贡献比例。研究表明:1956—2012 年秃尾河基流不仅具持续显著减少特征,还有22 a 和8 a 的多尺度周期变化特征和突变特征,并以1979 和1996 年为突变点。与基准期相比,1980—1996 年降水和人类活动对基流的贡献率分别为54.16%和45.84%;1997—2012 年降水和人类活动所占的比例分别为30.11%和69.89%;人为驱动力占总驱动力的比例显著上升,可以认为在全球气候变化的背景下,人类活动日益成为秃尾河基流演变的主要驱动因子。

Assessing the Impacts of Precipitation and Human Activities on Base Flow in the Midlle Tuwei River Basin of the Yellow River

Based on observed runoff time series at the Gaojiachuan hydrologic station from 1956 through to 2012 in the Tuwei River Basin, middle reaches of the Yellow River. The recursive digital filter technique was used to separate base flow. This paper analyzed the tendency, persistence, multi-scale and mutation characteristics of hydrological series. Finally, it calculated the contribution ratio of rainfall and human activities on the base flow by SCRAQ method. Results show that: The hydrological series of base flow from 1956 to 2012 has not only significant decrease trends and persistence characteristics, but also has 22 a, 8 a multiple time-scale and mutation features. 1979 and 1996 were taken as the change points in the hydrological series of base flow. Taking 1956-1979 as the base period, the contribution rate of the precipitation and human activities to the decreased base flow was 54.16% and 45.84% in 1980-1996; and 30.11% and 69.89% in 1997-2012. The human activity driving factors increased markedly, and it can be considered under the background of global climate change, human activities have become the main influencing factors of the evolution of base flow in the Tuwei River Basin.