Stream response to precipitation variability: a spectral view based on analysis and modelling of hydrological cycle components
Stream response to precipitation variability: a spectral view based on analysis and modelling of hydrological cycle components
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DOI：
10.1002/hyp.10293
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发表时间：
2015-03
影响因子：
3.2
通讯作者：
D. Markovic;M. Koch
中科院分区：
文献类型：
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作者：
D. Markovic;M. Koch
水文过程通常表现出长期持续性，也称为“赫斯特现象”。在这里，我们研究了易北河流域的长期降水和水流时间序列，以量化各个水文循环组成部分的光谱特性和赫斯特参数估计 (H^) 的差异。使用土壤和水评估工具 (SWAT) 对易北河子流域 Striegis 进行降水径流建模。对易北河流域 38 天、长达 50 年的水流时间序列进行了基流分离和光谱分析。结果显示，从降水到基流向低频尺度（>2 年）的频谱转变，H^ 从 0.52（降水）平行增加到 0.65（基流）。 SWAT 模型能够再现观测到的斯特里吉斯河流量时间序列的主要低频模式（约 7 年）和 H^ (0.62)。基流似乎是形成易北河流域水流对输入降水的低频响应和 H^ 的主要组成部分。通过对由各种土壤（沙子、壤质沙子和淤泥）组成的假设的与潜水流相连的含水层系统进行 PMWIN-MODFLOW 地下水建模，进一步证实了这一结论。当含水层的横向尺寸增加并且其水力传导率降低时，获得了向较低频率的功率转移以及水头的H ^ 的增加。沙土含水层、壤土含水层和淤泥含水层的地下水头平均 H^ 分别为 0.80、0.90 和 1.0。版权所有 © 2014 约翰·威利父子有限公司
Hydrological processes commonly exhibit long‐term persistence, also known as the ‘Hurst phenomenon’. Here, we examine long‐term precipitation and streamflow time series from the Elbe River Basin to quantify differences in the spectral properties and in the Hurst parameter estimates ( H^ ) of the individual hydrological cycle components. Precipitation‐runoff modelling is performed for the Elbe River sub‐catchment Striegis using the Soil and Water Assessment Tool (SWAT). For 38 daily 50 years long streamflow time series from the Elbe River Basin, baseflow separation and spectral analysis is performed. The results show a spectral shift towards low‐frequency scales (>2 years) from precipitation to baseflow, with a parallel increase of H^ from 0.52 (precipitation) to 0.65 (baseflow). The SWAT model is able to reproduce both, the main low‐frequency mode (≈7 yr.) and the H^ (0.62) of the observed Striegis River flow time series. The baseflow appears to be the main component which shapes the low‐frequency response and H^ of streamflow in the Elbe River Basin to the input precipitation. This conclusion is further confirmed through PMWIN‐MODFLOW groundwater modelling of a hypothetic phreatic stream‐connected aquifer system that consists of various soils (sand, loamy sand and silt). A power shift towards lower frequencies and an increase of H^ for the hydraulic heads is obtained, as the aquifer's lateral dimensions increase and its hydraulic conductivity decreases. The average H^ of the groundwater heads is 0.80, 0.90 and 1.0 for sand, loamy sand and silt aquifers, respectively. Copyright © 2014 John Wiley & Sons, Ltd.