Collaborative Research: Quantifying Feedbacks between Groundwater Decline, Wind Erosion, and Ecological Change in Desert Vegetation

该奖项将资助对地下水、土壤和植被特性之间的相互作用以及沙漠沙尘产生的分析。沙漠土壤的风蚀被认为会对生态系统造成不可逆转的变化，而被动员的颗粒物会严重降低空气质量。在全球的沙漠中，产生粉尘最多的地区的特点是低海拔洼地，那里的风可侵蚀物质已经并将继续以河流的形式沉积。浅层地下水通常从这些地区抽出，用于农业和市政用途。由于许多沙漠地区对水的需求迅速增加，因此越来越需要了解地下水管理可能如何影响粉尘的产生。理想情况下，可以获得指导地下水管理以促进土壤稳定为目标的信息。该项目将利用对植被和土壤条件以及风速的测量，在过去20年中经历了更大地下水波动的一系列地点建立风蚀模型。模型结果将与使用放射性尘埃同位素和尘埃捕集器直接测量近期土壤流失情况进行比较。最后，土壤资源有效性的测量(养分和土壤水分)将被用来理解地下水下降、土壤流失和可能导致土壤持续不稳定的生态系统变化之间的反馈过程。更广泛的影响：该项目将对我们理解水管理对沙漠中灰尘和空气质量的作用产生广泛影响。这项工作将在加州毕晓普附近拟议的研究区域内形成学术机构和监管团体之间的合作。Inyo县水务局和大流域空气污染控制区将为该项目提供必要的数据，并获得有关如何调整其植被和空气质量管理活动以获得长期可持续性的重要信息。

This award will fund an analysis of the interactions between groundwater, soil and vegetation properties, and desert dust generation. Wind erosion of desert soils is thought to cause irreversible change to ecosystems, and the mobilized particulate matter can seriously degrade air quality. In deserts globally, regions that produce the most dust are characterized by low elevation depressions where wind erodible material has been and continues to be deposited fluvially. Shallow groundwater is often pumped from these regions for agricultural and municipal use. Since water demands are rapidly increasingly in many desert regions, there is increasing need to understand of how groundwater management might influence dust generation. Ideally, information could be attained that would guide groundwater management with the goal of promoting soil stability. This project will utilize measurements of vegetation and soil conditions and wind velocities to model wind erosion at a range of sites that experienced successively greater groundwater fluctuation over the past 20 years. Model results will be compared to direct measurements of recent soil loss using radiogenic fallout isotopes and dust traps. Finally, measurements of soil resource availability (nutrients and soil moisture) will be used to understand feedback processes between groundwater decline, soil loss, and ecosystem changes that might promote continued soil instability. Broader Impacts: The project will have a broad impact on our understanding of the role water management has on dust and air quality in deserts. The work will form collaborations between academic institutions and regulatory groups in the proposed study region, near Bishop, California. Both the Inyo County Water Department and the Great Basin Unified Air Pollution Control District will provide necessary data to the project and gain important information on how their vegetation and air quality management activities could be tailored to gain long-term sustainability.