Abstract：
As one of the most devastating tropical storms, 2017 Hurricane Harvey caused severe flooding and damage in Houston, Texas. Besides enormous rainfall amount, land subsidence might be another contributing factor to the Harvey flood. However, few studies have numerically quantified the evolvement of land subsidence over decades, largely due to the lack of reliable methods to realistically estimate land subsidence both continuously and at high spatial resolution. Therefore, this study aims to investigate retrospective changes of regional topology due to 117 years (1900 to 2017) of land subsidence and the consequent impacts on flood inundation. Based on continuous land subsidence, we conduct a series of simulations on the 2017 Hurricane Harvey in Brays Bayou, Texas using a hydrodynamic/hydraulic model. The results indicate that the overall change of flood depth caused by land subsidence is relatively minor with the flood water deepened by six centimeters per one meter of subsided land at the worst impacted location. The impact from land subsidence on flood depth exhibits strong nonlinearity in time, where effects from previous land subsidence hotspots could be altered by later continuing land subsidence. Spatially, changes in flood depth due to the land subsidence are not only heterogeneous but mixed with coexisting increased and reduced flood depths. The results of this study improve the understanding of the dynamic evolvement of flood inundation due to continuous land subsidence so that better planning can be initiated for sustainable urban development for coastal communities, which is imperative under ongoing climate change and sea level rise.
摘要：
作为最具破坏性的热带风暴之一，2017年飓风哈维在休斯顿造成了严重的洪水和破坏，德克萨斯州。除了巨大的降雨量，地面沉降可能是哈维洪水的另一个促成因素。然而,很少有研究对几十年来地面沉降的演变进行数值量化，主要是由于缺乏可靠的方法来连续和高空间分辨率地实际估计地面沉降。因此,本研究旨在调查120年（1900年至2017年）地面沉降引起的区域拓扑变化及其对洪水淹没的影响。基于持续的地面沉降，我们在BraysBayou对2017年飓风哈维进行了一系列模拟，德克萨斯州使用流体动力/水力模型。结果表明，地面沉降引起的洪水深度总体变化相对较小，在影响最严重的位置，洪水每米沉降土地加深6厘米。地面沉降对洪水深度的影响在时间上表现出较强的非线性,以前地面沉降热点的影响可能会被后来的持续地面沉降所改变。空间上,地面沉降引起的洪水深度变化不仅是异质的，而且与洪水深度的增加和减少并存。这项研究的结果提高了对连续地面沉降引起的洪水淹没的动态演变的理解，从而可以为沿海社区的可持续城市发展启动更好的规划。在持续的气候变化和海平面上升的情况下，这是当务之急。
