Collaborative Research: Data Fusion for Characterizing and Understanding Water Flow Systems in Karst Aquifers

含水层是储存和传输地下水的地质材料，为美国51%的人口提供饮用水。地下水也是能源生产、农业和工业不可缺少的资源。岩溶含水层是一种特殊类型的含水层，它形成于可溶岩石(通常是碳酸盐岩)之下的区域。岩溶含水层拥有美国40%的地下水。随着时间的推移，可溶岩石的溶解在岩溶含水层中创造了一个复杂的地下水流动系统，其典型的特征是通过天坑、下沉的溪流和泉水连接到地表水的裂隙和管道网络。这些特点使岩溶含水层可能容易受到气候变化和污染的影响。拟议的研究旨在加强对岩溶含水层中复杂的裂隙和管道网络的了解，以便在人类活动压力增加的情况下，推进对许多岩溶含水层中的水流、地表水和地下水相互作用、污染物迁移、营养循环和碳循环的预测。该项目还将极大地惠及经济困难的阿巴拉契亚喀斯特地区，那里的学生在STEM(科学、技术、工程和数学)中的代表性不足。该项目由水文科学(HS)计划和已建立的激励竞争性研究计划(EPSCoR)共同资助。这项研究将集中于使用互补数据融合方法进行协作研究。该方法融合了从水力层析成像、河流水位层析成像、电阻率层析成像和示踪剂测试中收集的数据，以具有成本效益的方式生成了更可靠的岩溶含水层裂缝和管道地图。反过来，这些结果将有助于更好地理解和预测岩溶含水层中的流动和溶质运移。该项目的总体目标是开发、测试和验证一种基于数据融合概念的用于详细描述岩溶含水层特征的创新方法。为了实现这一目标，本研究将设计两种新的野外调查：地表和地下河流水位层析成像和移动电流源的电阻率层析成像。这项研究还将探索自然闪电层析成像用于大范围电阻率测量的可行性。从这些调查中收集的数据将被整合到基于地质统计学的反演框架中，以更详细地描述裂缝和管道的分布和形态。这种融合方法将在肯塔基州中部的甘霖皇家温泉盆地进行测试和验证。将使用现场收集的水位、水化学、示踪剂和稳定同位素数据来评估表征岩溶含水层的有效性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Aquifers are geologic materials that store and transmit groundwater and supply drinking water for 51% of the total U.S. population. Groundwater is also an indispensable resource for energy production, agricultural and industrial uses. A karst aquifer is a special type of aquifer that is formed in regions underlain by soluble rocks, typically carbonate rocks. Karst aquifers hold 40% of U.S. groundwater. The dissolution of soluble rocks through time creates a complex groundwater flow system in karst aquifers, which is typically characterized by a network of fractures and conduits that connect to the surface water through sinkholes, sinking streams, and springs. Those characteristics make karst aquifers potentially vulnerable to both climate change and contamination. The proposed research seeks to enhance understanding of the complex network of fractures and conduits in karst aquifers in order to advance the prediction of water flow, surface water and groundwater interaction, contaminant transport, nutrient cycle, and the carbon cycle in many karst aquifers under increased stresses from human activities. This project will also greatly benefit the economically distressed karst Appalachian region where students are underrepresented in STEM (Science, Technology, Engineering, and Mathematics). This project is jointly funded by the Hydrologic Sciences (HS) Program and the Established Program to Stimulate Competitive Research (EPSCoR). This research will be centered on conducting collaborative research using a complementary data fusion approach. The approach fuses data collected from hydraulic tomography, river stage tomography, electrical resistivity tomography, and tracer tests to produce a more reliable map of fractures and conduits in karst aquifers in a cost-effective manner. In turn, the results will lead to improved understanding and prediction of flow and solute transport in the karst aquifers. The overarching goal of this project is to develop, test, and validate an innovative approach for characterizing karst aquifers in detail based on the data fusion concept. To achieve this goal, this research will design two new field surveys: surface and subsurface river stage tomography and electrical resistivity tomography with moving current sources. This research will also explore the feasibility of natural lightning tomography for large-scale resistivity surveys. The data collected from these surveys will be integrated into a geostatistical-based inversion framework to characterize the distribution and morphology of fractures and conduits with great detail. The fusion approach will be tested and validated at the Cane Run Royal Spring Basin in central Kentucky. The validity of the characterized karst aquifers will be evaluated using a separate model with the field-collected water level, water chemistry, tracer, and stable isotope data.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.