Flooding Dynamics Within an Amazonian Floodplain: Water Circulation Patterns and Inundation Duration
Flooding Dynamics Within an Amazonian Floodplain: Water Circulation Patterns and Inundation Duration
复制标题
亚马逊河漫滩内的洪水动态：水循环模式和淹没持续时间
DOI：
10.1029/2019wr026081
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发表时间：
2020
影响因子：
5.4
通讯作者：
F. Seyler
中科院分区：
文献类型：
--
作者：
Sébastien Pinel;M. Bonnet;Joecila S. Da Silva;Tania C. Sampaio;J. Garnier;T. Catry;S. Calmant;C. R. Fragoso;D. Moreira;D. Motta Marques;F. Seyler
通过将遥感数据和有限的现场数据整合到基于Telemac - 2D模型的水文 - 水动力模型中，对亚马逊河/索利蒙伊斯河沿岸一个中等规模（雅瑙阿卡湖，面积786平方公里）的洪泛区系统在9年期间（2006 - 2015年）的洪水动态进行了研究。模型精度在水文年中有所变化。我们重点关注水循环的季节性和年际空间变异性以及淹没持续时间。我们强调了洪泛区不同地貌区域之间水流速度大小的强烈异质性，在河 - 洪泛区河道中遇到的流速最高。除了地形，我们强调主河道和当地径流在控制水循环方面的重要性，至少在水文年的部分时间是如此。从枯水期到水位上升初期，当地径流限制了河流对洪泛区的侵入，而主河道水位上升/下降的速率控制着洪水持续时间。对几个水文年的比较突出了这些水力控制因素的年际变化以及先前淹没条件所施加的影响。虽然我们观察到水文年之间水流速度分布变化不大，但淹没持续时间变化很大。通常由最高水位来定义，极端洪水事件可能矛盾地导致淹没持续时间出现正异常（多达40天），也可能出现负异常（多达 - 20天）。
Flooding dynamics across a medium‐size (Janauaca Lake, 786 km2) floodplain system along the Amazon/Solimoes River over a 9‐year period (2006–2015) is studied through integration of remote sensing and limited in situ data in hydrologic‐hydrodynamic modelling based on Telemac‐2D model. Model accuracy varies through the hydrological year. We focus on seasonal and interannual spatial variability of water circulation and inundation duration. We highlight strong heterogeneities in water velocity magnitude between the different morphological domains of the floodplain, the highest velocities being encountered in the river‐floodplain channel. In addition to topography, we emphasize the importance of the main channel and the local runoff in controlling the water circulation, at least during part of the hydrological year. From low water to early rising period, local runoff constrains the river incursion across the floodplain, while the rates of main channel rising/receding controls the flood duration. The comparison of several hydrological years highlights the interannual changes of these hydraulic controls and also the influence exerted by prior inundation conditions. While we observed few changes in water velocity distribution among hydrological years, the inundation duration is highly variable. Usually defined by maximum water level, extreme flood events may paradoxically induce positive (up to 40 days) but also negative (up to −20 days) anomalies of inundation duration.