Assessing the Driving Forces of Submarine Groundwater Discharge

评估海底地下水排放的驱动力

• 批准号: 0520723
• 负责人: William Burnett
• 金额: --
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0520723&HistoricalAwards=false
• 关键词: Assessing; Driving; Forces; Submarine; Groundwater

ABSTRACTOCE-0520723Submarine groundwater discharge (SGD) represents an important, yet largely unquantified pathway for nutrients and other dissolved constituents from land to the coastal ocean. Coastal oceanographers and hydrologists have shown that slow yet persistent seepage of fresh groundwater through sediments occurs wherever an aquifer with a positive head is hydraulically connected to a surface water body. It is now recognized that a considerable amount of seawater is also recirculated through coastal aquifer systems and that both fresh and saline water inputs contribute nutrients and other dissolved solids to coastal waters. However, the relative importance of the driving processes and the extent to which saline water flow is coupled to fresh water discharges is still not well understood and the predictive capabilities are lacking. For this reason, researchers at Florida State University will investigate the forces that drive both fresh and saline groundwater discharges. Since both terrestrial (hydraulic gradient, seasonal recharge cycle) and marine (wave setup, tidal pumping, water level differences) forces drive subsurface fluid flows through coastal aquifers and nearshore sediments, this team of scientists will examine these processes via a cross-disciplinary approach. It is critical to tackle the problem of SGD from both ends (terrestrial and marine), and from both disciplines (hydrology and oceanography) because driving forces overlap in time and space and the resultant fluid flow measured through coastal sediments is often a result of composite forcing. The project will separate and evaluate these forcing functions by a combination of long-term measurements (i.e., isotopic tracers, seepage meters), hydrological/geophysical investigations, and numerical modeling. The goal is to develop a long-term data set on all parameters that are relevant to SGD and its driving forces. Since many SGD drivers have known temporal variations, the frequency of the parameters and the ensuing SGD responses will be measured to deconvolute the influence of the forces.In terms of broader impacts, this study will significantly advance our understanding of the mechanisms controlling SGD. Proposing to carry out the work prior to coastal development at the site will provide a baseline from which to assess the impact of commercial/residential development on coastal aquifers in the future. To disseminate information to coastal zone manager on SGD and its implications, a workshop will be held during the third year of the project. Graduate and undergraduate students will be involved in the field and laboratory studies of the project.

Abstractoce-0520723Submarine地下水出院（SGD）代表了从陆地到沿海海洋的养分和其他溶解成分的重要但很大程度上的养分途径。沿海海洋学家和水文学家表明，在液压液压层与地表水体上连接的含水层在任何地方都会发生缓慢而持续的新鲜地下水渗透。现在已经认识到，还通过沿海含水层系统再循环大量的海水，新鲜和盐水输入都为沿海水域贡献了营养和其他溶解的固体。但是，驾驶过程的相对重要性以及盐水流与淡水排放的程度尚不清楚，并且缺乏预测能力。 因此，佛罗里达州立大学的研究人员将调查驱动新鲜和盐水地下水排放的力量。 由于陆地（液压梯度，季节性补给周期）和海洋（波浪设置，潮气，水位差异）都可以通过沿海含水层和近岸沉积物来驱动地下流体流动，因此该科学家将通过跨学科方法检查这些过程。至关重要的是，从两端（陆地和海洋）以及两个学科（水文和海洋学）解决SGD的问题至关重强迫。 该项目将通过长期测量（即同位素示踪剂，渗水仪），水文/地球物理研究和数值建模的组合分开和评估这些强迫功能。目的是针对与SGD及其驱动力相关的所有参数开发长期数据集。 由于许多SGD驱动因素已经知道了时间变化，因此参数的频率和随后的SGD响应将被衡量以反应力的影响。在更广泛的影响方面，这项研究将大大提高我们对控制SGD的机制的理解。 提议在现场进行沿海开发之前进行工作，将提供一个基线，以评估商业/住宅开发对沿海含水层的影响。 为了将信息传播给SGD及其含义的沿海地区经理，该项目将在项目的第三年举行。 研究生和本科生将参与该项目的现场和实验室研究。