Area representative soil water content estimations from limited measurements at time-stable locations or depths

JOURNAL OF HYDROLOGY

卷:530

Article

She, Dongli^1,2  Zhang, Wenjuan¹  Hopmans, Jan W.³  Timm, Luis Carlos⁴ 

[1] Hohai Univ, Minist Educ, Key Lab Efficient Irrigat Drainage & Agr Soil Wat, Nanjing 210098, Jiangsu, Peoples R China

[2] Chinese Acad Sci, Inst Soil Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Jiangsu, Peoples R China

[3] Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA

[4] Univ Fed Pelotas, Fac Agron, Dept Rural Engn, BR-96001970 Pelotas, RS, Brazil

关键词: Root-zone soil water;    Time stability;    Sampling schemes;   

DOI  :  10.1016/j.jhydrol.2015.10.016

来源: Elsevier

【 摘 要 】

To minimize the number of soil water content (SWC) measurements for estimation of field- or watershed-scale soil water storage, we present an analysis of time-stable soil water data across both measurement locations and soil depth intervals. The proposed analysis applies the time stability concept to select area-representative measurement locations, and assesses the potential for identifying the most time-stable depth interval (MTSD) using a minimal number of selected time-stable locations (MTSLs). For that purpose, we used a time series of 21 SWC datasets, measured at 20 locations and 20 corresponding depth intervals down a 3-m soil profile, during a two-year period in the 38-ha study area of the Liudaogou watershed of the China Loess Plateau. After identifying the MTSLs, analysis of time stability of measurement depth intervals showed single soil water depth measurements at between 2 and 5 of the MTSLs were sufficient to determine the area-representative SWC. The MTSD was determined to be about midway in the soil profile, irrespective of total soil profile depth measured. Confirmation of the time-stability analyses was done by comparing the representative SWC estimations for the 38-ha sampling area with additional SWC measurements across the 6.9 km(2) watershed. The encouraging results of our analysis suggest that time stability analysis may be an effective way to assess large-scale soil water storage in arid and semi-arid regions. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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