Regional differences in hydrological response to canopy interception schemes in a land surface model

Authors

  • Chi Zhang,

    1. School of Hydraulic Engineering, Dalian University of Technology, Dalian, P.R. China
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  • Dagang Wang,

    Corresponding author
    1. Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou, P. R. China
    2. Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute, Sun Yat-sen University, Guangzhou, P.R. China
    3. Guangdong Key Laboratory for Urbanization and Geo-simulation School of Geography Science and Planning, Sun Yat-sen University, Guangzhou, P. R. China
    • Correspondence to: Dagang Wang, School of Geography Science and Planning, Sun Yat-sen University, 135 West Xingang Road, Guangdong Province, P. R. China 510275.

      E-mail: wangdag@mail.sysu.edu.cn

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  • Guiling Wang,

    1. Department of Civil and Environmental Engineering, University of Connecticut, Storrs, USA
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  • Weitao Yang,

    1. Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou, P. R. China
    2. Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute, Sun Yat-sen University, Guangzhou, P.R. China
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  • Xiaoping Liu

    1. Guangdong Key Laboratory for Urbanization and Geo-simulation School of Geography Science and Planning, Sun Yat-sen University, Guangzhou, P. R. China
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Abstract

Two different canopy interception schemes are applied to the parameterization of the hydrological processes in the Community Land Model version 3. One scheme treats rainfall and canopy water storage as spatially uniform within each model grid cell, and the other scheme considers sub-grid variability of rainfall and water storage in the parameterization of canopy hydrological processes. The hydrological responses to differences between these two schemes in different regions are studied. It is found that the impact of the sub-grid variability in the tropical regions is generally greater than the extra-tropical regions. However, such impact can't be negligible for the extra-tropical regions. Soil water in the total 3.4 m soil depth increases by 3% for Central-South Europe, and vegetation temperature increases by 0.14 °C for Southeastern United States if the regional averages are considered. The magnitude of the impact is greater if the analysis focuses on the specific grid cells in these regions. The impact is tightly correlated with rainfall amount and vegetation density. The correlation coefficient between such impact and rainfall amount and vegetation density varies with regions and hydrological variables, with the largest value of 0.92 for interception loss in Amazonia. Our results indicate that the impact of the sub-grid variability on hydrological processes in the extra-tropical areas is also important, although rainfall amount and vegetation density in these areas are not as high as in the tropical areas. Copyright © 2013 John Wiley & Sons, Ltd.

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