Collaborative Research (SGER): Wildfire Impacts on Catchment Hydrochemistry: Metal and Nutrient Transport after the Day Fire, 2006

野火虽然是一种自然的周期性现象，但对流域具有直接的、有时甚至是毁灭性的影响。野火的影响包括高陆上流速、高沉积速率、水质下降和破坏性泥石流。由于其地中海气候（冬季潮湿，夏季干燥），秋季盛行的圣安娜风，以及不断扩大的人口，南加州容易在城市-荒地界面发生大范围火灾，这是引起许多观察到的火灾的原因。最近发生在洛杉矶北部的日火，烧毁了近254平方英里的国家森林和指定的荒野地区。大城市地区的几个主要饮用水水库位于日火烧伤区下游，这对水资源管理者来说是一个紧迫而严重的问题。其中一个水库位于燃烧的东部边缘，是金字塔湖，它储存着来自加利福尼亚渡槽的水以及来自皮鲁河流域的自然流入的水。本提案的目的是了解火灾后流域控制养分、金属和其他污染物通量的物理和化学机制，重点是金字塔湖水库系统。SGER拨款对实现这一目标至关重要，因为它允许立即开展现场活动，重点关注与可能的主要问题相关的物理和化学参数。知识价值。这项工作解决了火灾对流域系统中金属和养分运输和循环影响的基本问题。通过在一个流域系统内对陆地、水和沉积物阶段的多个参数进行协调的、时空密集的观测，我们将能够阐明火灾后流域的复杂运输关系。虽然已有大量文献证明了火灾对水文过程的影响，但我们并不完全了解火灾后系统中沉积物通量与营养物质和金属运输之间的关系。最终，我们计划利用收集到的数据建立火灾后流域系统中营养物质、金属和沉积物运输的机制和流域尺度模型。更广泛的影响。拟议的研究为理解关键的水质问题提供了一个独特的机会，同时也与正在进行的水文和地貌学研究协同作用，以确定和解决焚烧流域响应和恢复的基本问题。我们的研究将首次调查火灾对河流-水库系统中营养物质和金属运输的潜在影响，该系统是半干旱地区区域供水的一个组成部分。生态系统和供水管理人员将能够利用本研究收集的信息制定缓解和预警策略，以减少燃烧流域金属和养分通量增加的影响。这一建议也将有助于培养一个博士。加州大学洛杉矶分校的研究生，以及太平洋大学加州大学洛杉矶分校的本科生。加州大学洛杉矶分校的本科生将开展涉及数据收集和分析、实地调查和/或建模研究的本科研究项目（asCEE199），太平洋大学的本科生将把数据收集和分析纳入毕业论文项目。

Proposal SummaryWildfire, although a natural and periodic phenomena, has an immediate and sometimes devastatingeffect on watersheds. The impacts of wildfire can include high rates of overland flow, highsedimentation rates, decreased water quality, and destructive debris flows. Southern California isprone to widespread fires at the urban-wildland interface due to its Mediterranean climate (wetwinters, dry summers), prevalent Santa Anna winds during the fall season, and an ever-expandingpopulation which is responsible for igniting many of the observed fires. The Day Fire, whichrecently occurred north of Los Angeles, consumed nearly 254 square miles of National Forest anddesignated wilderness areas. Several major drinking water reservoirs for the metropolitan region arelocated downstream from the Day Fire burn area, presenting an immediate and serious concern forwater resource managers. One of these reservoirs, located on the eastern fringe of the burn, isPyramid Lake, which stores water from the California Aqueduct as well as natural inflows from thePiru Creek watershed. The objective of this proposal is to understand the physical and chemicalmechanisms that control nutrient, metal and other contaminant fluxes in post-fire watersheds, with afocus on the Pyramid Lake reservoir system. A SGER grant is critical to this objective as it allows animmediate field campaign focused on the physical and chemical parameters related to likely primaryproblems.Intellectual Merit. This work addresses fundamental questions on the impacts of fire on metal andnutrient transport and cycling in watershed systems. By enabling coordinated, spatiotemporallydense observations of multiple parameters in terrestrial, aqueous and sediment phases within onewatershed system, we will be able to elucidate complex transport relationships in post-firewatersheds. While there has been considerable literature demonstrating the effects of fire onhydrologic processes, we do not fully understand the relationships between sediment flux andnutrient and metal transport in post-fire systems. Ultimately, we plan to use the collected data todevelop mechanistic and watershed scale models of nutrients, metals and sediment transport in postfirewatershed systems.Broader Impacts. The proposed research represents a unique opportunity to understand a crucial waterquality issue, while also synergizing with on-going hydrological and geomorphologic studies todefine and address issues fundamental to response and recovery in burned watersheds. Our studywill be the first to investigate the potential effects of fire on nutrient and metal transport in a streamreservoirsystem which is an integral part of the regional water supply in a semi-arid region.Ecosystem and water supply managers will be able to utilize information gathered in this study todevelop mitigation and warning strategies for reducing the impacts from increased metal andnutrient fluxes in burned watersheds. This proposal will also contribute to the education of onePh.D. graduate student at UCLA, as well as undergraduate students at the University of the Pacificand UCLA. UCLA undergraduate students will develop undergraduate research projects (taken asCEE199) involving data collection and analysis, field surveys, and/or modeling studies, and Pacificundergraduate students will incorporate data collection and analysis into Senior Thesis projects.