CAREER: Understanding Processes related to Arroyo systems, southern Utah

职业：了解与阿罗约系统相关的过程，犹他州南部amy Rittenour，犹他州立大学这个职业资助项目旨在测试有关驱动机制的假设，这些机制导致了犹他州南部六个相邻的半干旱流域重复（且知之甚少）的壕沟和再沉积事件（阿罗约切填循环）。方法和拟议的活动遵循三个研究目标，每个目标都旨在从不同的角度解决这个长期存在的“阿罗约问题”。这些工作包括：1)对过去的切填旋回进行详细的、年代准确的地层记录（使用光激发发光和放射性碳定年法），完成流域的地貌测绘和GIS分析；2)利用宇宙成因放射性核素分析（10Be）表征河道沉积物的产沙量和侵蚀速率，以及与OSL特征和沉积物侵蚀速率相关的创新应用，研究驱动沉积的过程；3)通过调查现代洪水水文和年际流量变化，以及利用树木年轮年表来扩展降水和流量的仪器记录，了解阿罗约沟快速形成的驱动力。总之，这些研究方法和目标旨在为“阿罗约问题”带来新的数据和分析。——美国西南部长期存在的地貌和土地管理挑战。在上个世纪之交（公元1880 +/- 30年），美国西南部的许多河流和溪流迅速切割成洪泛区，形成了深深的阿罗约（在几年到几十年内深达30米），并在水源上方留下了定居点和家园。这一快速事件是美国西南部最重要的地貌事件之一，并造成了许多环境和经济问题。该项目将对犹他州南部六个相邻的排水系统进行多层次的现代分析，以重新解决与“阿罗约问题”相关的长期问题。考虑到未来温室气体条件下干旱频率和洪水严重程度的预测变化，这项关于半干旱河流系统对过去变化的响应的研究尤其及时。这项职业发展补助金有一个重要的教育组成部分，将包括向受所研究河流影响区域内的当地农村学区和土地管理人员提供外联服务。

EAR-1057192 CAREER: Understanding Processes related to Arroyo systems, southern UtahTammy Rittenour, Utah State UniversityThis CAREER grant project is designed to test hypotheses about the driving mechanisms that have led to repeated (and poorly understood) entrenchment and re-aggradation events (arroyo cut-fill cycles) in six adjoining semi-arid drainages in southern Utah. Methods and proposed activities follow three research objectives, each designed to approach this longstanding 'arroyo problem' from different angles. These are 1) developing a detailed and well-dated stratigraphic record of past cut-fill cycles (using optically stimulated luminescence, or OSL, and radiocarbon dating) and completing geomorphic mapping and GIS analysis of the watersheds, 2) investigating the processes that drive aggradation by characterizing sediment production and erosion rates using cosmogenic radionuclide analysis (10Be) of channel sediment and an innovative application relating OSL characteristics and sediment erosion rates, and 3) understanding the driving forces behind rapid arroyo entrenchment by investigating the modern flood hydrology and inter-annual discharge variability as well as using tree-ring chronologies to extend the instrumental record of precipitation and discharge. Together, these research methods and aims are designed to bring new data and analyses to bear on the 'arroyo problem? --a long-standing geomorphic and land management challenge in the southwestern US.At the turn of the last century (1880 +/- 30 AD), numerous rivers and streams in the southwestern US rapidly incised into their floodplains forming deep arroyos (up to 30m deep within years to decades), and left settlements and homesteads perched above their water sources. This rapid event is one of the most significant geomorphic events in the SW US and has caused numerous environmental and economic problems. This project will use a multi-tiered set of modern analyses in six adjoining drainages in southern Utah to re-address long-standing questions related to the 'arroyo problem'. This research on the response of semi-arid river systems to past change is especially timely given projected changes in drought frequency and flood severity under future greenhouse gas conditions. This CAREER grant has a significant education component and will include outreach to the local rural school districts and land managers within the regions impacted by the streams being studied.