Department of Earth and Environment, Florida International University, Miami, FL, United States of America.
Southeast Environmental Research Center (SERC), Institute of Water & Environment, Florida International University.
PLoS One. 2019 Feb 12;14(2):e0212008. doi: 10.1371/journal.pone.0212008. eCollection 2019.
Freshwater demand in Southeast Florida is predicted to increase over the next few decades. However, shifting patterns in the intensity and frequency of drought create considerable pressure on local freshwater availability. Well-established water resources management requires evaluating and understanding long-term rainfall patterns, drought intensity and cycle, and related rainfall deficit. In this study, the presence of rainfall monotonic trends was analyzed using linear regression and Mann-Kendal trend tests. Pettit's single point detection test examined the presence of an abrupt change of rainfall. Drought in Southeast Florida is assessed using the Standardized Precipitation Index (SPI) in 3-, 6-, 12-, and 24-months scale; and the Fast Fourier Transform is applied to evaluate the frequency of each drought intensity. There was an increase of rainfall in most of the wet season months, the total wet season, and the annual total. The wet season duration showed a decrease driven by a decrease in October rainfall. Since 1990, wet season and total annual rainfall exhibited an abrupt increase. The SPI analysis has indicated that extended wetness characterizes the contemporary rainfall regime since 1995, except for the incidence of intermittent dry spells. Short-term droughts have 3-year to 5-year recurrence intervals, and sustained droughts have a 10-year and 20-year recurrence intervals. In Southeast Florida, prolonged drought limits freshwater availability by decreasing recharge, resulting in a longer hydro-period to maintain the health of the Everglades Ecosystem, and to control saltwater intrusion. The increasing dry season duration suggests the growing importance of promoting surface water storage and demand-side management practices.
佛罗里达州东南部的淡水需求预计在未来几十年内会增加。然而，干旱强度和频率的变化模式给当地淡水供应带来了相当大的压力。成熟的水资源管理需要评估和了解长期降雨模式、干旱强度和周期，以及相关的降雨亏缺。在本研究中，使用线性回归和 Mann-Kendal 趋势检验分析了降雨单调趋势的存在。Pettit 的单点检测检验检查了降雨的突然变化是否存在。使用标准化降水指数 (SPI) 评估佛罗里达州东南部的干旱情况，SPI 的时间尺度为 3 个月、6 个月、12 个月和 24 个月；并应用快速傅里叶变换评估每个干旱强度的频率。大多数湿季月份、整个湿季和全年的降雨量都有所增加。湿季持续时间的减少是由 10 月降雨量减少驱动的。自 1990 年以来，湿季和全年降雨量都出现了突然增加。SPI 分析表明，自 1995 年以来，扩展的湿润特征是当代降雨模式的特征，除了间歇性干旱的发生。短期干旱的重现期为 3 年至 5 年，持续干旱的重现期为 10 年和 20 年。在佛罗里达州东南部，长时间的干旱会通过减少补给来限制淡水的供应，从而延长水期以维持大沼泽地生态系统的健康，并控制海水入侵。旱季持续时间的增加表明，促进地表水储存和需求侧管理实践的重要性日益增加。
