Collaborative Research: Determining the eco-hydrogeologic response of tropical glacierized watersheds to climate change: An integrated data-model approach

最近冰川的迅速消退，特别是在厄瓜多尔安第斯山脉等热带地区，引发了关于水资源的重要问题。了解目前冰川退缩对这些地区供水的影响，可以揭示世界各地冰雪覆盖的山区分水岭未来的水安全威胁。冰川是山脉的“水塔”：它们在潮湿时期储存冰，在干燥时期逐渐释放融化的水。然而，地下水含水层是否作为扩展水库，以及植物是否也吸收大量冰川融化水，仍然是悬而未决的问题。这些不确定性使人们很难预测未来山区分水岭供水的可靠性，因为冰川首先加速融化，然后最终消失，随着植物因气温变暖而迁往更高的海拔。该项目将开发一种新的通用计算分水岭模型，其中将纳入用于追踪水流来源区域的化学和同位素数据，以及创新的低成本、开源环境监测技术的测量结果。该模型的结果可以向依赖冰雪覆盖的山区流域的河流流量的社区提供关于未来水资源脆弱性的现有信息，并可以在冰川消退加速时促进适应战略。冰川的退缩将削弱它们调节河流流量及其变化的能力。对这一水文后果的研究通常将融水和地下水归类为径流的不同贡献者，但这过度简化了冰川、其底层地下水系统和生态水文路径之间潜在的复杂关系。研究人员建议在四个快速变化的冰川化厄瓜多尔流域中使用综合数据模型方法来评估这些关系，其中两个流域分别位于Volcán Chimborazo和Volcán Cayambe。这项工作将产生一种新的具有反应输送的同位素分水岭模型，其中将引入数据同化，以便在具有稳健环境示踪剂的数据稀疏分水岭中为不确定模拟提供条件。用于测量模型输入数据的开源数据记录器和传感器将进一步推动对临界区过程的理解，使其超越数据密集型现场，进入正在经历世界上一些最迅速的环境变化的偏远环境。这项工作将揭示研究较少的火山山脉，这些山脉可能会促进融水通过其破裂的基岩更多地渗透，并扩大已建立的专注于冰川消退的水资源，在研究冰川消退的冰川山区分水岭的水文响应时也考虑植被变化。这一奖项反映了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。

Recent rapid glacier retreat, especially in tropical regions such as the Ecuadorian Andes, raises important questions about water resources. Understanding the current effects of glacier retreat on water supply in these regions can shed light on future water security threats in snow and ice-covered mountainous watersheds worldwide. Glaciers are the "water towers" of the mountains: they store ice during wet periods and gradually release meltwater during dry periods. However, whether groundwater aquifers serve as extended reservoirs and whether plants also take up significant glacial meltwater remain unresolved questions. These uncertainties make it difficult to predict the future reliability of water supply in mountainous watersheds, as glacier melt first accelerates and then eventually disappears, and as plants move to higher elevations in response to warming temperatures. This project will develop a new and general computational watershed model that will incorporate chemical and isotopic data for tracing water flow source regions, as well as measurements from innovative low-cost, open-source environmental monitoring technologies. Results from the model can inform communities that rely on stream discharge from ice and snow-covered mountainous watersheds about present with regard to future water resources vulnerabilities, and can facilitate adaptation strategies as glacier retreat accelerates. The recession of glaciers will curtail their ability to modulate river discharge and its variability. Studies of this hydrologic consequence typically classify meltwater and groundwater as distinct contributors to streamflow, but this oversimplifies the potentially complex relationships among glaciers, their underlying groundwater systems, and ecohydrologic pathways. The investigators propose to assess these relationships using an integrated data-model approach in four rapidly changing, glacierized Ecuadorian watersheds, two each at Volcán Chimborazo and Volcán Cayambe. This work will produce a new isotope-enabled watershed model with reactive transport, to which data assimilation will be introduced in order to condition uncertain simulations in data-sparse watersheds with robust environmental tracers. Open-source data loggers and sensors for measuring model input data will further advance critical-zone process understanding beyond data-intensive sites to remote settings that are undergoing some of the most rapid environmental change in the world. This work will shed light on less-studied volcanic ranges that potentially facilitate greater infiltration of meltwater through their fractured bedrock, as well as expand the established water-resources focus on glacier retreat to also consider vegetation shift when examining the hydrologic response of glacierized mountainous watersheds to glacier retreat.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.