SGER: Spatial Patterns of Flood Sedimentation in Response to an Extreme Event: Guadelupe River, Texas

虽然洪泛区的研究一直是河流地貌学的支柱，大洪水事件的洪泛区建设的重要性还不清楚。 这是特别重要的解释气候变化的影响（无论是在过去和展望未来）对排水系统，因为洪水沉积物作为代理证据洪水和景观响应。 潮湿的沿海平原河流系统已经得到了深入的研究，但德克萨斯州的半干旱和干旱排水系统可能对大降雨事件特别敏感，对这些环境中的洪泛区过程的研究要少得多。 这笔探索性研究小额赠款将支持一个项目，调查得克萨斯州中东部瓜达尔卡尔特河流域的洪水沉积，该流域在2002年7月初经历了一次极端洪水事件。 该项目考虑了下游流域控制对洪水沉积模式和特征的影响。 该项目的大部分内容将以实地为基础，并从USGS 1：24，000地形图和数字正射影像中获取补充数据。 洪水沉积物的厚度将在现场测量，洪水沉积物的粒度分析将在得克萨斯大学地貌实验室进行。 将使用全站仪测量绘制洪泛区地形图和沉积物样品的位置。 将通过考虑洪泛区地形、河谷尺寸（坡度和宽度）、洪水状况（流量、水位、淹没长度）和平面河道形态来检查流域对洪水沉积的控制。 河岸植被对沉积的影响将通过比较每个站点内和站点之间的树冠覆盖率和树木密度来考虑。该项目预计将在理论上有助于理解大型事件对洪泛区建设的重要性。 它将评估各种控制措施如何影响洪水沉积物的空间尺度（体积和粒度）。 在区域上，该项目将增加对西部海湾沿海平原河流系统中洪泛平原沉积的了解。该项目将为学生参与实地工作提供宝贵的机会，并通过后续活动，使调查人员能够更有效地教授基本实地技术、河流地貌学和利用地理信息系统的分析方法。 该项目还将产生数据，可能被证明是相当有用的地方官员，因为他们计划未来的洪水预防和控制战略。

Although floodplain research has been a mainstay of fluvial geomorphology, much is not known about the importance of large flood events to floodplain construction. This is particularly significant with respect to the interpretation of the influence of climate change (both in the past and looking ahead to the future) on drainage systems, because flood deposits serve as proxy evidence for flooding and landscape response. Humid coastal plain fluvial systems have been studied intensively, but the semi -arid and arid drainage systems of Texas may be particularly sensitive to large rainfall events, and far less research has been devoted to floodplain processes in these settings. This Small Grant for Exploratory Research will support a project that investigates flood sedimentation in the Guadalupe River valley of east central Texas, which experienced an extreme flood event in early July 2002. The project considers the influence of downstream drainage basin controls on the pattern and character of flood deposits. Most of the project will be field based, with supplemental data obtained from USGS 1:24,000 topographic maps and digital orthophotos. The thickness of the flood deposits will be measured in the field, and particle size analysis of flood sediments will occur in the University of Texas geomorphology laboratory. Total-stations surveying will be used for mapping the floodplain topography and location of sediment samples. The drainage basin controls on flood sedimentation will be examined by considering the floodplain topography, valley dimensions (gradient and width), flood regime (discharge, stage, length of inundation), and the planform channel morphology. The influence of riparian vegetation on sedimentation will be considered by comparing the canopy cover and tree density within each site, and between sites.The project is expected to contribute theoretically to understanding of the importance of large events to floodplain construction. It will assess how various controls influence the spatial dimensions of flood deposits (volume and particle size). Regionally, the project will increase understanding of floodplain sedimentation in western Gulf Coastal Plain fluvial systems.. this project will provide valuable opportunities for student involvement in the fieldwork, and through follow-up activities, it will enable the investigator to be more effective in teaching fundamental field techniques, fluvial geomorphology, and analytic approaches using geographic information systems. The project also will yield data that may prove to be quite useful for local officials as they plan future flood-prevention and -control strategies.