Collaborative Research: Multi-tracer Investigation of Interbasin Groundwater Transfer in the Lowland Rainforest of Costa Rica

0439732 Genereux现有数据表明，跨流域地下水流（IGF）下的表面地形划分负责大量的水和溶质的输入到哥斯达黎加的一些低地雨林流域。 在这项工作中，年龄测定示踪剂和微量气体将与稳定同位素和主要离子一起使用，以测试这个概念的水文模型混合的老区域地下水（IGF）和更年轻的当地地下水的流域。 使用的示踪剂是CFCs、3 H/3 He、SF6、4 He、14 C、36 Cl、18 O、溶解的示踪气体（Ne、Ar、Kr、N2和O2）和主要离子。 在雨季和旱季，将在地下水、泉水和（仅适用于非挥发性示踪剂）溪流中测量示踪剂。 该项目将：1。 提高对重要但研究不足的水文过程IGF的理解：只要存在IGF，对其进行定量了解对于理解低地流域的水文和水质以及这些流域作为生态系统的地位和功能至关重要。 2. 通过将几种示踪剂方法同时应用于新环境（火山地质雨林）中重要水文过程的适定问题，测试它们的一致性：测试我们的概念水文模型还将测试最先进的示踪剂数据在识别和量化复杂排放区中不同年龄的地下水之间的混合方面的通用性。3. 帮助说明IGF的土地/水管理的实际意义：这里测试的概念水文模型表明，充分保护低地雨林流域和生态系统需要了解一个区域地下水系统，其体积，边界和补给区目前尚不清楚（但将受到结果的限制）。 对这一模式的支持将强调在互联网治理论坛存在的情况下对土地和水资源管理采取区域办法的重要性，并推动在其他地点进一步研究互联网治理论坛。 推进教育和研究：该项目将有很强的教育/培训的研究生谁将掌握几个国家的最先进的示踪剂技术的好处。 研究合作伙伴（NCSU，USGS，犹他州大学和热带研究组织）将建立合作关系，加强他们目前的研究和培训活动，使这项工作成为可能，并有可能延续到未来的活动。

0439732GenereuxExisting data suggest interbasin groundwater flow (IGF) beneath surface topographic divides is responsible for large inputs of water and solutes to some lowland rainforest watersheds in Costa Rica. In this work age-dating tracers and trace gases will be used together with stable isotopes and major ions to test this conceptual hydrologic model for mixing of old regional groundwater (IGF) and much younger local groundwater in the watersheds. The tracers to be used are CFCs, 3H/3He, SF6, 4He, 14C, 36Cl, 18O, dissolved trace gases (Ne, Ar, Kr, N2, and O2), and major ions. Tracers will be measured in groundwater, spring water, and (for the non-volatile tracers only) streamwater, during both the wet season and dry season. The project will:1. Improve understanding of an important but understudied hydrologic process, IGF: Wherever IGF exists, quantitative knowledge of it is central to understanding the hydrology and water quality of lowland watersheds, and the status and function of those watersheds as ecosystems. 2. Test the consistency of several tracer methods through their simultaneous application to a well-posed problem on an important hydrologic process in a new setting (rain forest with volcanic geology): Testing our conceptual hydrologic model will also test the general utility of state-of-the-art tracer data in identifying and quantifying mixing between groundwaters of very different age in a complex discharge area.3. Help illustrate the practical significance of IGF for land/water management: The conceptual hydrologic model to be tested here suggests that full protection of lowland rainforest watersheds and ecosystems requires understanding a regional groundwater system whose volume, boundaries, and recharge areas are currently not known (but will be constrained by the results). Support for the model would underscore the importance of a regional approach to land and water management in the presence of IGF, and motivate further study of IGF at other sites.4. Advance education and research: The project will have strong educational/training benefits for a graduate student who will master several state-of-the-art tracer techniques. The research partners (NCSU, USGS, Univ. of Utah, and the Organization for Tropical Studies) will build collaborations that enhance their current research and training activities, make this work possible, and have the potential to carry over to future activities.