Imaging a Natural Experiment in Drainage Divide Migration

对分水岭迁移的自然实验成像智力优势-本提案的目标是获取和分析科罗拉多高平原约18平方公里野外场地的高分辨率数字地形数据，该数据代表了陡坡退缩和分水岭迁移的自然实验。该遗址提供了一个独特的机会来记录地形的发展，并在不同的基础水平控制下测试基于物理的景观演化理论。更大的重要性是双重的。首先，水系分界迁移是景观对构造、游动和其他形式的基准面控制反应的一个基本方面。其次，测试基于物理的景观演变模型需要自然实验，包括对已知强迫因素（如基线水平）的短暂响应。高分辨率的研究级激光测高数据对于实现这些目标至关重要，因为标准的USGS数字高程数据缺乏必要的分辨率和精度来记录控制过程的地形特征，提取用于模型数据比较的统计数据，以及绘制切割表面。这个项目很及时，因为国家机载激光测绘中心（NCALM）将于今年夏天启动一项任务，从科罗拉多州的其他地点获取数据。如果研究区域的数据是在NCALM 2006年科罗拉多任务期间收集的，那么数据成本将大大降低。这些数据将被分析以确定特征地形特征，包括坡度和曲率图以及频率分布、坡度-面积图、区域聚集指数和相关指标。它们还将用于重建一系列切割的山谷填充物和高地表面的前范围。这些数据，当与切割和填充事件的时间限制相结合时，将提供一种独特的方法来测试景观演化模型及其对差异基线降低响应的分水岭迁移的预测。使用CHILD模型的探索性迭代正演建模将用于确定过程规律和参数集，这些规律和参数集可以或不能解释观测到的地形和土壤厚度。这个项目的成功将带来更大的努力，将产生地质年代学数据、实时过程监测和沉积物产量估算，从而形成一个全面的数据集，供研究团体用于测试其他地形演化模型。请注意，除了本提案要求的预算外，还要求为NCALM的数据采集提供资金。如果获得资助，佛罗里达大学将要求这些费用的补充预算。更广泛的影响-这项研究的更广泛的影响分为几类。高分辨率的测高数据将直接支持博士学位论文的研究。科罗拉多大学的学生，从而为教学，培训和学习做出贡献。该项目通过向科学界提供一个有价值的研究地点的测高数据和相关信息来增强基础设施；除了具有重要的地貌学意义外，该地区还包括世界著名的白垩纪-第三纪界线剖面。广泛的传播将不仅通过出版物和会议的常规途径来确保，而且还将通过向平原保护中心和丹佛自然科学博物馆提供数据和图像来确保。平原保护中心是一个拥有该遗址的非营利性土地保护和公共教育组织，丹佛自然科学博物馆领导了对K-T边界部分的研究，并在与丹佛盆地地质相关的研究型公共宣传方面有着良好的记录。对社会的好处包括我们对土壤侵蚀、运输和沉积的理解的进步，这适用于土地管理。

Imaging a Natural Experiment in Drainage Divide MigrationIntellectual Merit - The objective of this proposal is to acquire and analyze highresolutiondigital topography data for an ~18km2 field site in the Colorado high plainsthat represents a natural experiment in scarp retreat and drainage divide migration.The site offers a unique opportunity to document landform development and testphysically based landscape evolution theory under differential baselevel control. Thelarger importance is two-fold. First, drainage divide migration is a fundamental aspectof landscape response to tectonics, eustasy, and other forms of baselevel control.Second, testing physically based landscape evolution models requires naturalexperiments that involve a transient response to a known forcing factor, such asbaselevel. High-resolution, research-grade laser altimetry data are essential toachieving these goals because standard USGS digital elevation data lack the necessaryresolution and accuracy to document the topographic signatures of the governingprocesses, extract statistics for model-data comparison, and map incised surfaces. Theproject is timely because the National Center for Airborne Laser Mapping (NCALM)will launch a mission to acquire data from other sites in Colorado this summer. Thecost of data will be significantly lower if the data for the study area are collectedduring NCALM's 2006 Colorado mission. The data will be analyzed to determinecharacteristic topographic signatures, including slope and curvature maps andfrequency distributions, slope-area diagrams, area aggregation indices, and relatedmetics. They will also be used to reconstruct the former extent of a series of incisedvalley fills and upland surfaces. These data, when combined with timing constraintson cut and fill events, will provide a unique method for testing landscape evolutionmodels and their predictions about divide migration in response to differentialbaselevel lowering. Exploratory iterative forward modeling using the CHILD modelwill be used to identify process laws and parameter sets that can and cannot accountfor the observed topography and soil thickness. Success in this project is expected toseed a larger effort that will generate geochronology data, real-time processmonitoring, and sediment-yield estimates, resulting in a comprehensive data set foruse by the research community in testing other landform evolution models. Note thatin addition to the budget requested in this proposal, funds are also requested for dataacquisition by NCALM. If funded, the University of Florida will request asupplemental budget for these expenses.Broader Impacts - The broader impacts of this research fall into several categories.The high-resolution altimetry data will directly support the dissertation research of aPh.D. student at the University of Colorado, thus contributing to teaching, training,and learning. The project enhances infrastructure by providing the scientificcommunity with altimetry data and associated information for a valuable researchsite; in addition to its geomorphic importance, the area encompasses a world-famousterrestrial Cretaceous-Tertiary boundary section. Broad dissemination will be ensurednot only through the usual routes of publications and conferences, but also byproviding data and images to the Plains Conservation Center, a non-profit landconservation and public education organization that owns the site, and to the DenverMuseum of Natural Science, which leads research on the K-T boundary section andhas a strong track record in research-based public outreach related to the geology ofthe Denver Basin. Benefits to society include advances in our understanding of soilerosion, transport, and deposition, which is applicable to land management.