Journal article
Spectral Analysis of Hydrological Signals to Estimate Watershed Properties Considering Impacts of Unsaturated Zone
Water resources research, Vol.60(11), e2023WR036680
11/2024
DOI: 10.1029/2023WR036680
Abstract
Abstract Understanding responses of stream discharge to precipitation in a watershed is important in gaining insights into watershed hydrology and estimating hydraulic parameters. Transfer functions in the spectral domain are commonly used to quantify the relationship between precipitation and discharge, and estimate watershed hydraulic parameters. However, previous models have not adequately accounted for the impact of the unsaturated zone. To address this, we have developed a novel analytical model that considers the effect of the unsaturated zone to obtain transfer functions within watersheds. These transfer functions are derived by the spectral method and verified through numerical simulations. The results indicate that the transfer functions are influenced significantly by the relative hydraulic conductivity exponent α k in the moisture characteristic curve. A higher α k results in a lower transfer function, indicating more robust filtering of hydrological signals. A thicker unsaturated zone results in lower transfer functions at higher frequencies. The traditional transfer functions, which neglect the retention capacity of the unsaturated zone, tend to overestimate hydrological responses at high frequencies. Our transfer functions agree well with integrated watershed‐scale flow models and are also applied to observed data from four watersheds in Iowa, providing reasonable estimates for the hydraulic parameters. This study contributes to a deeper understanding of watershed behavior and offers an enhanced tool for estimating hydraulic parameters with practical applications.
Key Points Transfer functions are proposed to quantify hydrological signal filtration considering unsaturated flow described by Richards equation Thicker unsaturated zones or higher conductivity exponents enhance the filtration of hydrological signals Unsaturated zone generally possesses a stronger ability to filter watershed hydrological signals than that of saturated zone
Details
- Title: Subtitle
- Spectral Analysis of Hydrological Signals to Estimate Watershed Properties Considering Impacts of Unsaturated Zone
- Creators
- Yunqiu Zhou - Southern University of Science and TechnologyXiuyu Liang - Southern University of Science and TechnologyEnze Ma - Southern University of Science and TechnologyKewei Chen - Southern University of Science and TechnologyKeith Schilling - University of IowaTianyuan Zheng - Ocean University of ChinaYuhu Zheng - Nanjing UniversityYou‐Kuan Zhang - Southern University of Science and TechnologyChunmiao Zheng - Southern University of Science and Technology
- Resource Type
- Journal article
- Publication Details
- Water resources research, Vol.60(11), e2023WR036680
- Publisher
- AMER GEOPHYSICAL UNION
- DOI
- 10.1029/2023WR036680
- ISSN
- 0043-1397
- eISSN
- 1944-7973
- Grant note
- National Natural Science Foundation of ChinaGuangxi Science and Technology Planning Project: GuiKe AD21075013 Natural Science Foundation of Shenzhen: 20220814221815001 Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control: 2023B1212060002 High-level University Special Fund: G03050K001
This study was partially supported by research grants from the National Natural Science Foundation of China (42372289), Guangxi Science and Technology Planning Project (Grant GuiKe AD21075013), the National Natural Science Foundation of China (42172275), Natural Science Foundation of Shenzhen (20220814221815001), Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control (No. 2023B1212060002), and the High-level University Special Fund (G03050K001).
- Language
- English
- Date published
- 11/2024
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984742559702771
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