Collaborative Research: RAPID: Short-and Long-term Sediment Dynamics Following Wildfire in Chaparral Environments

这个快速项目的重点是生产和交付干式RAVEL，这是美国西部陡峭山坡上的一种具有特色的火灾后即时反应。干碎屑产生于旱季的运输过程，在此过程中，沙砾沉积物在重力作用下沿山坡向下移动，并被植被捕获。这种材料在丛林环境中的野火后为河道提供了重要的沉淀物来源。2013年5月，斯普林斯大火烧毁了南加州的大梧桐峡谷，调查人员将对沿海峡边缘沉积的干RAVEL沉积物的体积进行量化。在雨季(通常在10月1日左右开始)前后，地面激光扫描将捕捉到地形地貌的初步变化。这些数据将通过实地调查加以补充。火灾后第一年收集的数据对于建立干式滑车动力学模型很重要。调查人员掌握了大Sycamore峡谷和附近两个具有不同火灾历史的类似盆地超过25年的地貌数据--1985年7月惠勒大火期间完全烧毁的北福克Matilija Creek的支流--以及至今仍未被烧毁的Malibu Creek的支流。比较这三个地点的干Ravel过程将使人们能够直接比较森林环境中野火后的短期和长期沉积物动力学。发展对野火短期和长期影响的预测性理解是至关重要的，特别是在一个气候变化的时代，野火的频率和规模都有所增加。然而，准确预测火灾后的影响仍然难以捉摸，基于物理的火灾后径流和侵蚀模型仍在开发中。拟议的项目将通过让加州州立大学海峡群岛分校(CSUCI)的本科生参与进来，将研究和教育结合起来。这些学生将继续他们最高水平的本科课程，同时协助PI收集和分析现场数据。其中两名学生是CSUCI校园内西班牙裔服务学院Acceso(通过STEM机会实现合作学院教育)研究助理计划的参与者。这些学生将获得宝贵的研究经验，包括使用尖端技术的培训。

This RAPID project focuses on production and delivery of dry ravel, a characteristic and immediate post-fire response on steep slopes in the western USA. Dry ravel arises from a dry-season transport process whereby gravel sediment moving down hillslopes by gravity becomes trapped by vegetation. This material provides a significant sediment source into river channels after wildfire in chaparral environments. The investigators will quantify the volume of dry ravel sediment deposited along channel margins as a result of the Springs Fire that burned Big Sycamore Canyon in southern California during May 2013. Terrestrial laser scanning before and after the rainy season (which typically begins around October 1) will capture initial changes in landscape topography. These data will be augmented by field surveys. Data collected during the first post-fire year are important for developing models of the dynamics of dry ravel. The investigators have geomorphic data spanning over 25 years for Big Sycamore Canyon and two comparable basins nearby with different fire histories--a tributary to north fork Matilija Creek that burned completely during the July 1985 Wheeler Fire-- and a tributary to Malibu Creek that has remained unburned. Comparing dry ravel processes at these three sites will enable a direct comparison of both short- and long-term sediment dynamics following wildfire in chaparral environments. Developing a predictive understanding of both short- and long-term effects of wildfire is critical, especially in an era of changing climate that has increased frequencies and magnitudes of wildfires. Yet, accurately predicting post-fire effects remains elusive, and physically-based models of post-fire runoff and erosion are still being developed. The proposed project will integrate research and education by involving undergraduate students from California State University, Channel Islands (CSUCI). These students will pursue their capstone undergraduate coursework while assisting the PIs with field data collection and analysis. Two of these students are participants of the Hispanic-Serving Institutes ACCESO (Achieving a Cooperative College Education Through STEM Opportunities) Research Assistant Program on the CSUCI campus. These students will receive valuable research experiences including training in use of cutting-edge technologies.