SGER: Sampling and Isotopic Analysis of Yucatan Groundwater: Impact of Hurricane Isadore

0313847Perry该提案旨在评估热带风暴降水（尤其是飓风降水）作为地下水运动自然示踪剂的用途。众所周知，热带风暴的降水具有特殊的氧和氘同位素组成，使其与正常降水区分开来。由于热带风暴产生的降雨量是普通风暴的数倍，因此它们能够在一次事件中向含水层添加大量水。本研究的目的是确定同位素标记的水段在穿过含水层时是否可以通过稳定同位素测量来追踪。这项研究可以建立一种强大的新技术来研究飓风频繁的热带地区的地下水。 计划和建立一个适合监测飓风的实验是很困难的，而且仅仅因为热带风暴可能发生在该网络内的某个地方，而建立一个大型监测站网络将是昂贵的。这就是为该提案增添了紧迫性的原因。飓风伊萨多尔最近掠过尤卡坦半岛北部，PI 此前已在该地区获得了当地地下水同位素组成的背景数据。尤卡坦半岛北部特别适合试验这种监测技术：其喀斯特含水层渗透性极强，可确保地下水快速流动；它几乎没有可能阻碍飓风降水快速流入含水层的土壤；而且含水层相对不复杂。因此，当飓风降水通过时，监测该含水层中水成分的变化将相对容易。 地下水样本将在一年内分三次采样采集。这些数据将从市政井、覆盖的喀斯特污水坑和渗压计（如果有）获得。学生将参与收集样本和分析数据。同位素分析将在墨西哥国立自治大学的稳定同位素实验室进行。 该项目的智力价值将是更好地了解地下水这一宝贵资源的行为，并开发一种新的、无污染的技术来绘制地下水的运动图。这项活动的更广泛影响将包括：1）开发地下水运动信息，从而更好地管理和保护非常敏感的尤卡坦含水层地下水（对人类健康、农业生产力、工业发展和旅游业至关重要），2）通过本研究的密切合作，在墨西哥科学家和美国科学家之间建立更密切的合作，以及3）对学生进行有关收集有意义的地下水样本和评估分析结果的程序的教育本研究的。

0313847PerryThis proposal is to evaluate the use of tropical storm precipitation,especially that from hurricanes, as a natural tracer of groundwatermovement. Precipitation from tropical storms is known to have a specialoxygen and deuterium isotope composition that distinguishes it fromnormal precipitation. Because tropical storms also produce many times asmuch rain as normal storms, they are capable of adding a large batch orslug of water to an aquifer during a single event. The objective of thisstudy is to determine whether that slug of isotopically labeled watercan be traced by stable isotope measurements as it moves through anaquifer. This research could establish a powerful new technique to studygroundwater in tropical areas where hurricanes are frequent. It is difficult to plan and set up an experiment suitable formonitoring a hurricane, and it would be expensive to establish a largenetwork of monitoring stations purely on the chance that a tropicalstorm might occur somewhere within that network. That is what adds anelement of urgency to this proposal. Hurricane Isadore recently passedover the northern Yucatan Peninsula, an area where the PI has previouslyobtained background data on the isotopic composition of the localgroundwater. Northern Yucatan is especially well suited for a trial ofthis monitoring technique: its karst aquifer is extremely permeable,insuring rapid groundwater movement; it has almost no soil that mightimpede rapid movement of the hurricane precipitation into the aquifer;and the aquifer is relatively uncomplicated. Thus, it will be relativelyeasy to monitor changes in the composition of water in this aquifer asthe hurricane precipitation moves through. Samples of groundwater will be collected in three sampling tripsover a period of one year. These will be obtained from municipal wells,covered karst sinkholes, and piezometers (where available). Studentswill be involved in collecting the samples and analyzing the data.Isotopic analyses will be performed in the stable isotope laboratory ofthe Universidad Nacional Autonoma de Mexico. Intellectual merit of this project will be a betterunderstanding of the behavior of groundwater, a precious resource, andthe development of a new, non-polluting technique for charting itsmovement. The broader impacts of this activity will include: 1)development of information on groundwater movement that can lead tobetter management and protection of groundwater in the very sensitiveYucatan aquifer (essential for human health, agricultural productivity,industrial development, and tourism), 2) establishment of closercollaboration between Mexican scientists and scientists in the UnitedStates, accomplished by close collaboration in this research, and 3)education of students in the procedures used to collect meaningfulsamples of groundwater and to evaluate the analytical results of thisstudy.