Tampa Bay Water, Clearwater, Florida, United States of America.
PLoS One. 2013;8(1):e53832. doi: 10.1371/journal.pone.0053832. Epub 2013 Jan 11.
Florida is riddled with sinkholes due to its karst topography. Sometimes these sinkholes can cause extensive damage to infrastructure and homes. It has been suggested that agricultural practices, such as sprinkler irrigation methods used to protect crops, can increase the development of sinkholes, particularly when temperatures drop below freezing, causing groundwater levels to drop quickly during groundwater pumping. In the strawberry growing region, Dover/Plant City, Florida, the effects have caused water shortages resulting in dry-wells and ground subsidence through the development of sinkholes that can be costly to maintain and repair. In this study, we look at how frost-freeze events have affected West Central Florida over the past 25 years with detailed comparisons made between two cold-years (with severe frost-freeze events) and a warm year (no frost-freeze events). We analyzed the spatial and temporal correlation between strawberry farming freeze protection practices and the development of sinkholes/dry well complaints, and assessed the economic impact of such events from a water management perspective by evaluating the cost of repairing and drilling new wells and how these compared with using alternative crop-protection methods. We found that the spatial distribution of sinkholes was non-random during both frost-freeze events. A strong correlation between sinkhole occurrence and water extraction and minimum temperatures was found. Furthermore as temperatures fall below 41°F and water levels decrease by more than 20 ft, the number of sinkholes increase greatly (N >10). At this time alternative protection methods such as freeze-cloth are cost prohibitive in comparison to repairing dry wells. In conclusion, the findings from this study are applicable in other agricultural areas and can be used to develop comprehensive water management plans in areas where the abstraction of large quantities of water occur.
佛罗里达州由于其喀斯特地形而遍布天坑。有时，这些天坑会对基础设施和房屋造成广泛的破坏。有人认为，农业 practices，例如用于保护作物的 sprinkler 灌溉方法，会增加天坑的 development，尤其是当 temperature 降至 freezing 以下时，会导致 groundwater 水平在 groundwater 抽取过程中迅速下降。在佛罗里达州的草莓种植区 Dover/Plant City，这种影响导致了水资源短缺，造成了水井枯竭和地面沉降，因为天坑的 development 成本高昂，难以维护和 repair。在这项研究中，我们研究了过去 25 年来佛罗里达州中西部的 frost-freeze events 如何影响该地区，详细比较了 two 个 cold-years（有 severe frost-freeze events）和一个 warm-year（没有 frost-freeze events）。我们分析了 strawberry farming freeze protection practices 与天坑/dry well 投诉的 development 之间的时空相关性，并从 water management 的 perspective 评估了这些 events 的经济 impact，通过评估 repair 和 drilling new wells 的成本以及使用替代 crop-protection methods 的成本来进行评估。我们发现，在两次 frost-freeze events 期间，天坑的 spatial distribution 是非随机的。我们发现天坑的 occurrence 与 water extraction 和 minimum temperature 之间存在很强的相关性。此外，当 temperature 降至 41°F 以下且 water level 下降超过 20 英尺时，天坑的数量会大大增加（N >10）。此时，与 repair dry wells 相比，替代保护方法（如 freeze-cloth）的成本过高。总之，这项研究的结果适用于其他农业地区，并可用于在大量抽取 water 的地区制定综合 water management 计划。
