RAPID: Investigation of Immediate Post-fire Hydro-geochemical Coupling and Contaminant Flux in an Urban-fringe Watershed in Southern California

RAPID：对南加州城市边缘流域火灾后立即水文地球化学耦合和污染物通量的调查

• 批准号: 0965236
• 负责人: Terri Hogue
• 金额: $ 6万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-15 至 2011-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0965236&HistoricalAwards=false
• 关键词: RAPID; Investigation; Immediate; Post; fire

The Station fire is currently noted as the largest fire in Los Angeles County history as well as the 10th largest fire in California history. The burned region is located immediately adjacent to dense urban areas on the east side of the Los Angeles basin. These urban-wildland regions, located in the San Gabriel Mountains, will now be impacted by increased flooding, debris and sediment-laden flows, and significant water quality issues. The San Gabriel Mountains are known to receive high loads of atmospheric pollutants (dry and wet)originating from the Los Angeles metropolitan region. Runoff from these mountains normally supplies significant runoff into downstream urban water ways, which is then directed to infiltration ponds or zones for aquifer recharge, or into conveyance channels that route water through dense urban areas to coastal bays. Postfire runoff in these urban-fringe watersheds may now contribute significant, and potentially toxic, chemical loads into downstream urban systems, affecting regional water supplies, biota and ecosystem function. Funds from this RAPID grant will allow an immediate and extensive investigation of storm-driven contaminant flux (including nutrients, metals, PAHs, sediments, and other ancillary parameters) in an urban fringe watershed affected by significant atmospheric deposition and that was burned in its entirety. Previously collected pre-fire data on the study watershed will allow a unique and comprehensive comparison to pre-burn behavior,advance knowledge on post-burn hydro-geochemical coupling and alterations in basin mass loading, and provide critical data to improve geochemical and hydrologic modeling in post-burn systems. The overarching goal of the proposed research is to better understand the mechanisms controlling alterations in the chemical and physical response of urban fringe watersheds after a catastrophic wildfire. Specifically, we propose to address the following science questions: 1) How does post-fire hydro-geochemical coupling (behavior) alter from pre-fire conditions? 2) How does storm variability influence post-fire runoff behavior and coupled contaminant flux? 3) What is the effect of burn on riparian nitrate soil storage and streamwater export? and 4) What is the impact of a catastrophic burn on seasonal pollutant loading to downstream urban systems?

车站火灾目前被认为是洛杉矶县历史上最大的火灾，也是加州历史上第10大火灾。被烧毁的地区紧邻洛杉矶盆地东侧的密集城市地区。这些位于圣盖博山脉的城市荒地地区现在将受到洪水、泥石流和沉积物流增加以及严重水质问题的影响。已知圣盖博山脉接收来自洛杉矶大都市区的高负荷大气污染物（干的和湿的）。这些山脉的径流通常为下游城市水道提供大量径流，然后将其引导到渗透池或含水层补给区，或进入将水通过密集的城市地区输送到沿海海湾的输送渠道。这些城市边缘流域的火灾后径流现在可能会对下游城市系统产生重大的、可能有毒的化学负荷，影响区域供水、生物区系和生态系统功能。来自该RAPID赠款的资金将允许对受显著大气沉积影响的城市边缘流域中风暴驱动的污染物通量（包括营养物，金属，多环芳烃，沉积物和其他辅助参数）进行立即和广泛的调查，并被完全烧毁。以前收集的火灾前的研究流域的数据将允许一个独特的和全面的比较，燃烧前的行为，推进燃烧后的水文地球化学耦合和流域质量负荷的变化的知识，并提供关键数据，以改善地球化学和水文模拟后燃烧系统。拟议研究的总体目标是更好地了解灾难性野火后控制城市边缘流域化学和物理反应变化的机制。具体而言，我们建议解决以下科学问题：1）火灾后的水文地球化学耦合（行为）如何从火灾前的条件改变？2)风暴变异性如何影响火灾后径流行为和耦合的污染物通量？3)燃烧对河岸硝酸盐土壤储存和河水输出有什么影响？以及4）灾难性燃烧对下游城市系统的季节性污染物负荷有何影响？