Florida International University, Department of Earth and Environment, AHC-5 360, 11200 SW 8th Street, Miami, FL 33199, USA.
Broward College, 111 East Las Olas Boulevard, Fort Lauderdale, FL 33301, USA.
Sci Total Environ. 2018 Mar;616-617:1668-1688. doi: 10.1016/j.scitotenv.2017.10.170. Epub 2017 Dec 13.
Modeling of groundwater levels in a portion of the low-lying coastal Arch Creek basin in northern Miami-Dade County in Southeast Florida USA, which is subject to repetitive flooding, reveals that rain-induced short-term water table rises can be viewed as a primary driver of flooding events under current conditions. Areas below 0.9m North American Vertical Datum (NAVD) elevation are particularly vulnerable and areas below 1.5m NAVD are vulnerable to exceptionally large rainfall events. Long-term water table rise is evident in the groundwater data, and the rate appears to be consistent with local rates of sea level rise. Linear extrapolation of long-term observed groundwater levels to 2060 suggest roughly a doubling of the number of days when groundwater levels exceed 0.9m NAVD and a threefold increase in the number of days when levels exceed 1.5m NAVD. Projected sea level rise of 0.61m by 2060 together with increased rainfall lead to a model prediction of frequent groundwater-related flooding in areas<0.9m NAVD. However, current simulations do not consider the range of rainfall events that have led to water table elevations>1.5m NAVD and widespread flooding of the area in the past. Tidal fluctuations in the water table are predicted to be more pronounced within 600m of a tidally influenced water control structure that is hydrodynamically connected to Biscayne Bay. The inland influence of tidal fluctuations appears to increase with increased sea level, but the principal driver of high groundwater levels under the 2060 scenario conditions remains groundwater recharge due to rainfall events.
美国东南佛罗里达州迈阿密戴德县北部地势低洼的阿奇克里克流域部分地区的地下水位建模表明，在当前条件下，降雨引起的短期地下水位上升可被视为洪水事件的主要驱动因素。低于 0.9 米北美的垂直基准面 (NAVD) 高程的区域特别脆弱，而低于 1.5 米 NAVD 的区域则容易受到特大降雨事件的影响。地下水数据显示出长期地下水位上升的明显趋势，而且上升速度似乎与当地海平面上升速度一致。对长期观测到的地下水位进行线性外推到 2060 年，表明地下水水位超过 0.9 米 NAVD 的天数将增加约一倍，而水位超过 1.5 米 NAVD 的天数将增加两倍。到 2060 年，预计海平面上升 0.61 米，加上降雨量增加，导致模型预测在低于 0.9 米 NAVD 的地区经常发生与地下水有关的洪水。然而，目前的模拟并未考虑过去导致地下水位抬升至超过 1.5 米 NAVD 并广泛淹没该地区的一系列降雨事件。在与潮汐影响的水控结构水力连通的 600 米范围内，预计地下水位的潮汐波动会更加明显。随着海平面上升，潮汐波动的内陆影响似乎会增加，但在 2060 年情景条件下，导致高地下水位的主要驱动因素仍然是降雨事件引起的地下水补给。
