CAREER: Land Use, Geologic and Climatic Controls on Stream Processes in Northern New England Using Airborne Laser Swath Mapping

该项目综合了遥感数据分析、实地调查和测绘以及河流模型，以检验新英格兰北部冰川消融地貌中河流形态和过程的基本控制假说。在晚更新世大陆冰川覆盖的地区，河流通过基岩侵蚀、泥沙的可获得性和运输以及生态演替的共同作用而演变。河流形态和栖息地适宜性在下游方向有所不同，这取决于当地的沉积源和汇。从砍伐森林到保护河岸的历史土地利用变化进一步影响了河流过程。目前，在缅因州大西洋鲑鱼濒临灭绝的推动下，非营利组织和政府机构正在努力通过稳定流域沉积物输入和拆除大坝来扭转河流栖息地退化的趋势。然而，这些修复工作通常是由对其他地区鲑鱼河的地貌研究指导的。这一建议旨在了解景观对土地利用变化的响应轨迹，并开发和测试将河流物理过程与生境质量联系起来的空间数值模型。机载激光条带测绘(ALSM)将扩大过去15年来使用数字高程模型(DEM)在定量地貌学方面取得的进展。ALSM调查产生了对整个流域的“裸露”地形、森林覆盖厚度和水深的高分辨率测量。这项研究将收集缅因州三个流域的ALSM数据，并使用河道地貌测量作为输运过程的数值模型的输入。这些空间模型将通过与实地调查、地质和生态制图、鱼类种群数据集以及使用历史航空照片的过去条件进行比较来测试。本科生和硕士学生团队将进行研究，使用现场、地理空间和数值方法对每个流域进行合作。每个学生都将在团队中扮演一个角色，这个角色将演变为最终的研究项目的制作和演示。多年的学生参与将确保强有力的教授-学生、研究生-本科生和本科生-本科生指导。这项拟议的研究与新英格兰北部正在进行的生态系统恢复项目直接相关。这项研究的所有阶段都将包括由学生和PI进行直接外联，在从实地讲习班到全国会议的论坛上与土地管理员、流域恢复非营利组织、高中生和来自不同领域的其他科学家分享结果和方法。这些努力将包括基于研究结果的具体建议，以优化未来的修复项目。通过与社区团体的互动，学生将认识到土地管理决策过程中的挑战。学生和利益相关者之间的这种交流将确保研究具有强大的社会和科学影响。

This project integrates analysis of remote-sensing data, field surveys and mapping, and fluvial models to test hypotheses of the fundamental controls on stream form and process in the deglaciated landscape of northern New England. Rivers in regions covered by late Pleistocene continental glaciers evolve through a combination of bedrock erosion, availability and transport of bedload, and ecological succession. Stream morphology, and therefore habitat suitability, varies in the downstream direction, depending on local sedimentary sources and sinks. Historical land-use change from deforestation to riparian protection further influences fluvial processes. At present, motivated by the near extirpation of Atlantic salmon in Maine, non-profit groups and government agencies are working to reverse fluvial habitat degradation by stabilizing watershed sediment inputs and removing dams. However, these restoration efforts are typically guided by geomorphic studies of salmon rivers in other regions. This proposal seeks to understand the trajectory of landscape response to changes in land use, and develop and test spatial numerical models that relate stream physical processes to habitat quality.Airborne laser swath mapping (ALSM) will expand the advances made in quantitative geomorphology using digital elevation models (DEMs) over the past 15 years. ALSM surveys yield high-resolution measurements of "bare-earth" topography, thickness of forest cover, and water depth over entire watersheds. This study will collect ALSM data from three watersheds in Maine and use channel morphologic measurements as input for numerical models of transport processes. These spatial models will be tested through comparison to field surveys, geological and ecological mapping, fish-population datasets, and past conditions using historical aerial photographs.Teams of undergraduate and Master's students will conduct the research, working together on each of the watersheds using field, geospatial, and numerical methods. Each student will have a role within the team that evolves to eventual production and presentation of research projects. Multi-year student involvement will ensure strong professor-student, graduate-undergraduate, and undergraduate-undergraduate mentoring. The proposed research is directly relevant to ongoing ecosystem restoration projects in northern New England. All phases of this study will include direct outreach by students and the PI to share results and methods with land managers, watershed restoration non-profit groups, high school students, and other scientists from a variety of fields in forums from field workshops to national meetings. These efforts will include specific recommendations, based on research findings, for optimizing future restoration projects. Through interactions with community-based groups, students will gain an appreciation for the challenges of land-management decision-making processes. This exchange between students and stakeholders will ensure that the research has a strong societal and scientific impact.