Development of a distributed biosphere hydrological model and its evaluation with the Southern Great Plains Experiments (SGP97 and SGP99)
Development of a distributed biosphere hydrological model and its evaluation with the Southern Great Plains Experiments (SGP97 and SGP99)
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DOI：
10.1029/2008jd010800
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发表时间：
2009-04-22
影响因子：
4.4
通讯作者：
Yang, Dawen
中科院分区：
文献类型：
--
作者：
Wang, Lei;Koike, Toshio;Yang, Dawen
将生物圈方案（SiB 2）与基于地貌的水文模型（GBHM）充分耦合，建立了一个分布式生物圈水文模型，即基于水能平衡的分布式水文模型（WEB-DHM）。SiB 2描述了每个模式网格的大气和陆地表面之间的湍流通量（能量，水和碳通量）的转移。该模型通过栅格-坡面离散化模拟地表径流和地下径流，然后在河网中进行水流演算，从而实现水分的横向再分配。WEB-DHM进行了校准和验证的小沃希托盆地使用从南部大平原水文实验（SGP 97和SGP 99）的现场观测。对于SGP 97期间，模型进行了校准，它显示出再现点尺度能量通量（RMSE < 50 W m（-2））以及CO2通量（RMSE = 4.6 μ mol m（-2）s（-1））的能力。在流域尺度上，WEB-DHM可以模拟一个合理的过程线（纳什= 0.956）和空间土壤水分分布与校准只有少数土壤水力参数的流量。然后，使用SGP 99数据集和观测到的放电对模型进行验证。对于验证期间，该模型表现出良好的性能再现土壤表面温度在11个站点和表面土壤水分的空间分布，以及长期流量（纳什= 0.715）在水文年从1998年9月1日至1999年8月31日，涵盖了1999年的年度最大洪峰和SGP 99期间。据我们所知，这项工作是第一次利用这种全面的实地观测来开发和评估分布式生物圈水文模型。
A distributed biosphere hydrological model, the so-called water and energy budget-based distributed hydrological model (WEB-DHM), has been developed by fully coupling a biosphere scheme (SiB2) with a geomorphology-based hydrological model (GBHM). SiB2 describes the transfer of turbulent fluxes (energy, water, and carbon fluxes) between the atmosphere and land surface for each model grid. The GBHM redistributes water moisture laterally through simulating both surface and subsurface runoff using grid-hillslope discretization and then flow routing in the river network. The WEB-DHM was calibrated and validated for the Little Washita Basin using field observations from Southern Great Plains Hydrology Experiments (SGP97 and SGP99). For the SGP97 period, the model was calibrated and it shows an ability to reproduce point-scale energy fluxes (RMSE < 50 W m(-2)) as well as CO2 flux ( RMSE = 4.6 mu mol m(-2) s(-1)). At basin scale, the WEB-DHM can simulate a reasonable hydrograph (Nash = 0.956) and spatial soil moisture distribution with calibration of only a few soil hydraulic parameters for discharge. The model was then validated using SGP99 data sets and observed discharge. For the validation period, the model shows good performance in reproducing the soil surface temperature at 11 sites and the spatial distribution of surface soil moisture, as well as long-term discharges (Nash = 0.715) in the hydroyear from 1 September 1998 to 31 August 1999 that covers both the annual largest flood peak of 1999 and the SGP99 period. To our knowledge, this work is the first to undertake the development and evaluation of a distributed biosphere hydrological model using such comprehensive field observations.