Collaborative Research: Interactions between Holocene Lake Levels and Alluvial Fans in the Western U.S. in Response to Changing Climates

该项目的主要目标是在美国西部建立全新世晚期水文变化和景观响应的综合记录，以了解近期气候变化对景观过程的影响，从而为未来在不同气候情景下可能发生的情况提供模拟。这将通过整合四个不同盆地的晚全新世湖平面记录及其周围沿大盆地西部450公里南北样带的冲积扇记录来完成。金字塔湖、温尼穆卡湖、沃克湖和欧文斯湖周围凸起的海岸线反映了该地区水平衡的显著波动，形成了很好的时间标记，可以用来确定冲积扇洪水的时间、空间分布和类型。这些记录将通过对海岸线和扇区进行额外的年龄测定来增强，以进一步了解每个湖盆如何对全新世晚期气候的微妙波动做出反应，包括它们的水平衡以及气候变化引起的洪水的类型和频率。这项研究的广泛影响范围从教育活动和广泛传播结果到地质灾害评估。与河流洪水相关的灾害评估相比，冲积扇洪水灾害的划定科学相对不成熟。该项目将通过记录时间、频率、类型、空间范围和大面积年轻冲积扇活动的原因，为冲积扇洪水危害评估从业者提供关键信息。该项目将利用多种工具，包括地质制图、地貌学、沉积学、地层学、地质年代学、温度年代学、遥感、和古气候分析，在美国西部广阔的N-S地带开发水文变化和冲积扇活动的区域综合。该项目的跨学科性质使其能够教授学生第四纪地质学家使用的各种技能，并将有助于两名研究生的教育，以及参与该项目的本科生研究助理，以及大约15-20名其他学生，他们将在内华达大学里诺分校注册一门基于这项研究的课程。研究结果将在两次或更多的专业会议上发表，并在至少两篇同行评议的期刊文章中发表。为了接触到更广泛的受众，研究结果还将用于开发一个关于气候变化对景观影响的教育模块，该模块将在大盆地古环境数据库（GBPED）网站（http://www.dri.edu/gbped）上展示。GBPED是一个公众可访问的资源，可以在b谷歌earth上查看，它提供了关于环境变化各个方面的科学论文的摘要，以及显示研究地点的地点标记。

The primary goal of this project is to develop an integrated record of late Holocene hydrologic change and landscape response in the western U.S. to understand the effects of recent climate changes on landscape processes, thereby providing an analog for what may happen in the future under different climate scenarios. This will be accomplished by integrating late Holocene lake-level records of four different basins with their surrounding alluvial fan records along a 450 km north-south transect in the western Great Basin. Raised shorelines surrounding Pyramid and Winnemucca lakes, Walker Lake, and Owens Lake reflect significant fluctuations in the water balance of the region and form excellent time markers that can be used to establish the timing, spatial distribution, and types of floods on alluvial fans across broad areas. These records will be augmented by additional age dating of shorelines and fans to further understand how each lake basin responded to subtle late Holocene climate fluctuations, both in terms of their water balance and the types and frequencies of floods caused by altered climate regimes.The broader impacts of this research range from educational activities and broad dissemination of results to geologic hazard assessment. The science of delineating flood hazards on alluvial fans is relatively immature compared to assessing hazards associated with river floods. This project will provide critical information on alluvial fan flooding to practitioners of hazard assessments by documenting the timing, frequency, style, spatial extent, and causes of young alluvial fan activity across large areas. The project will utilize a diverse set of tools including geologic mapping, geomorphology, sedimentology, stratigraphy, geochronology, tephrochronology, remote sensing, and paleoclimate analysis to develop a regional synthesis of hydrologic variability and alluvial fan activity across a broad N-S swath of the western U.S. The interdisciplinary nature of this project lends itself to teaching students a variety of skill sets used by Quaternary geologists and will contribute to the education of two graduate students, as well as undergraduate research assistants involved in the project and about 15-20 other students who will enroll in a course based on this research at University of Nevada, Reno. Results will be presented at two or more professional meetings and published in at least two peer-reviewed journal articles. To reach a broader audience, results will also be used to develop an educational module on the effects of climate change on the landscape that will be featured on the Great Basin Paleoenvironmental Database (GBPED) web site (http://www.dri.edu/gbped). The GBPED is a publicly accessible resource viewable in Google earth that provides abstracts of scientific papers on all aspects of environmental change along with place marks that show where the studies were conducted.