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建立美国西部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。这将通过将四个不同盆地的全新世晚期湖水位记录与其周围沿大盆地西部 450 公里南北横断面的冲积扇记录相结合来实现。金字塔湖和温尼马卡湖、沃克湖和欧文斯湖周围升高的海岸线反映了该地区水平衡的显着波动，并形成了极好的时间标记，可用于确定广大地区冲积扇洪水的时间、空间分布和类型。这些记录将通过对海岸线和风扇进行额外的年龄测定来增强，以进一步了解每个湖盆如何应对全新世晚期微妙的气候波动，包括​​水平衡以及气候变化引起的洪水的类型和频率。这项研究的更广泛影响范围包括教育活动和广泛传播结果到地质灾害评估。与评估与河流洪水相关的危害相比，描述冲积扇洪水危害的科学相对不成熟。该项目将通过记录大面积年轻冲积扇活动的时间、频率、类型、空间范围和原因，为灾害评估从业者提供有关冲积扇洪水的重要信息。该项目将利用地质测绘、地貌学、沉积学、地层学、地质年代学、岩石年代学、遥感和古气候分析等多种工具，对美国西部南北宽阔地带的水文变化和冲积扇活动进行区域综合。该项目的跨学科性质有助于向学生传授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和本科生研究参与该项目的助理和大约 15-20 名其他学生将在内华达大学里诺分校报名参加基于这项研究的课程。结果将在两次或两次以上专业会议上公布，并发表在至少两篇同行评审的期刊文章中。为了吸引更广泛的受众，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 是一个可在 Google 地球中查看的公开资源，提供有关环境变化各个方面的科学论文摘要以及显示研究进行地点的地标。

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.