The effects of spatial resolution and dimensionality on modeling regional‐scale hydraulics in a multichannel river
The effects of spatial resolution and dimensionality on modeling regional‐scale hydraulics in a multichannel river
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空间分辨率和维度对多河道河流区域尺度水力学建模的影响
DOI：
10.1002/2016wr019396
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发表时间：
2017
影响因子：
5.4
通讯作者：
J. Neal
中科院分区：
文献类型：
--
作者：
E. Altenau;T. Pavelsky;P. Bates;J. Neal
随着区域和全球尺度的建模能力的提高，关于准确模拟多通道河流水力所需的适当过程表示仍然存在问题。这项研究使用水动力模型LISFLOOD-FP来模拟阿拉斯加州塔纳纳河∼90公里支流河段的水面高度、深度和淹没程度的模式。为了提供边界条件，我们在2013年夏季的一次为期两周的野外活动中收集了水深测量和WSE的现场观测数据。在这个尺度上，我们第一次测试了一个简单的、基于栅格的模型模拟WSE的二维、航道内模式和淹没程度的能力。此外，我们将较细分辨率(≤25m)的2-D模型与其他四个较低维度和较粗分辨率(100-500m)的模型进行比较，以确定简化过程表示的效果。结果表明，简单的基于栅格的模型可以准确地模拟塔纳河的二维河道水力。此外，与粗分辨率相比，精细分辨率的二维模型在WSE和淹没程度的时空输出上产生的误差更低，一维模型的WSE为22.6 cm，RMSE为56.4 cm，模拟淹没程度的临界成功指数值为90%，41%。对于较小的渠道，使用子网格表示法合并分支渠道网络对于精确模拟水力很重要，并且可以将空间分布的WSE中的RMSE降低至少16%。因此，需要在多渠道河流中使用次网格解算器或缩小尺度技术来更好地表示汇聚和发散的多渠道网络，以改善区域到全球尺度模型的误差。
As modeling capabilities at regional and global scales improve, questions remain regarding the appropriate process representation required to accurately simulate multichannel river hydraulics. This study uses the hydrodynamic model LISFLOOD‐FP to simulate patterns of water surface elevation (WSE), depth, and inundation extent across a ∼90 km, anabranching reach of the Tanana River, Alaska. To provide boundary conditions, we collected field observations of bathymetry and WSE during a 2 week field campaign in summer 2013. For the first time at this scale, we test a simple, raster‐based model's capabilities to simulate 2‐D, in‐channel patterns of WSE and inundation extent. Additionally, we compare finer resolution (≤25 m) 2‐D models to four other models of lower dimensionality and coarser resolution (100–500 m) to determine the effects of simplifying process representation. Results indicate that simple, raster‐based models can accurately simulate 2‐D, in‐channel hydraulics in the Tanana. Also, the fine‐resolution, 2‐D models produce lower errors in spatiotemporal outputs of WSE and inundation extent compared to coarse‐resolution, 1‐D models: 22.6 cm versus 56.4 cm RMSE for WSE, and 90% versus 41% Critical Success Index values for simulating inundation extent. Incorporating the anabranching channel network using subgrid representations for smaller channels is important for simulating accurate hydraulics and lowers RMSE in spatially distributed WSE by at least 16%. As a result, better representation of the converging and diverging multichannel network by using subgrid solvers or downscaling techniques in multichannel rivers is needed to improve errors in regional to global‐scale models.
影响因子：
13.5
作者：
S. Biancamaria;M. Durand;K. Andreadis;P. Bates;A. Boone;N. Mognard;E. Rodríguez;D. Alsdorf;D. Lettenmaier;E. Clark
通讯作者：
S. Biancamaria;M. Durand;K. Andreadis;P. Bates;A. Boone;N. Mognard;E. Rodríguez;D. Alsdorf;D. Lettenmaier;E. Clark
观察全球地表水洪水动态
影响因子：
4.6
作者：
Bates P
通讯作者：
Bates P