Collaborative Research: Delivery and Burial of Particulate Organic Carbon (POC) on Ocean Margins Dominated by Small, Mountainous Rivers: the Role of Effective Discharge

我们将研究控制不同类型陆源颗粒有机碳(POC)通过美国西海岸山区小河流运输的基本因素，重点是Umpqua、Eel和Salinas河。此外，我们将探索河流流量和邻近沿海海洋的波浪/风能之间的一致性，作为控制陆源POC最终命运的关键因素(即广泛的扩散和退化与局部的积累和保存)。为了实现这些目标，将从所有三条河流和泛滥平原沉积物中收集具有代表性的悬浮颗粒物样本，以量化各种排放过程中POC负荷的大小和组成。洪水过后，对洪泛平原和大陆边缘的沉积物进行事件反应采样，将提供对短期碳埋藏模式的洞察。还将在河流流域和沿海海洋收集更长的沉积物档案，以记录过去几千年来最大的事件，并在气候变化和人类引起的分水岭变化的背景下调查POC埋葬规模和组成的历史变化。我们将结合这些数据来调查与陆地-海洋连续体中不同类型的碳的输送和埋藏相关的事件的规模和频率。我们的结果将通过将它们与USGS测量站、NOAA海洋浮标和NWS气象站的数据集整合在一起，扩大到整个美国西海岸边缘。这项工作更广泛的意义和重要性在于，小型山区河流占全球向海洋输送颗粒物的50%，并主导着北美西海岸。然而，尽管碳在全球和区域上具有重要意义，但对于碳是如何从高地势盆地输送并埋藏在沿海边缘的，缺乏定量的了解。通过重点研究河流流量的变化，这项研究将在水文学和海洋学之间建立统一的联系。通过我们的事件响应采样，我们将开发新的方法来吸收来自陆地和海洋实时监测站的日益增长的信息流。最后，在不断变化的水文气候条件和土地利用方式下，河流流域的物质流量具有广泛的社会相关性。沉积物和与颗粒相关的有机污染物都是美国地表水中的常见污染物。因此，通过提供有关河流悬浮泥沙和碳负荷的新信息，并将知识扩展到罕见的高强度事件，我们将对研究区域内与污染物有关的问题提供重要的启示。

We will investigate the fundamental factors controlling the transport of different types of land-derived particulate organic carbon (POC) by small, mountainous rivers on the US West Coast with an emphasis on the Umpqua, Eel and Salinas Rivers. Moreover, we will explore the coherence between river discharge and wave/wind energy in the adjacent coastal ocean as the key factor controlling the ultimate fate of land-derived POC (i.e., widespread dispersal & degradation vs. localized accumulation & preservation). To achieve these objectives, representative samples of suspended particulate matter will be collected from all three rivers and from floodplain deposits to quantify the magnitude and composition of the POC load over a wide range of discharges. Event-response sampling of sediments from both the floodplains and continental margins following floods will provide insight into short-term carbon burial patterns. Longer sediment archives will also be collected within the river basins and coastal ocean to provide a record of the largest events over the past several millennia and to investigate historical changes in the magnitude and composition of POC burial in the context of climatic changes and human-induced alterations of the watersheds. We will combine these data to investigate the magnitude and frequency of events associated with the delivery and burial of different types of carbon across the land-ocean continuum. Our results will be up-scaled to the entire US West Coast margin by integrating them with data sets from USGS gauging-stations, NOAA ocean-buoys and NWS meteorological stations. The broader significance and importance of the work resides in the fact that small, mountainous rivers account for 50% of global transport of particulates to the ocean and dominate the west coast of North America. However, in spite of their global and regional importance, a quantitative understanding of how carbon is transported from high-relief basins and buried on coastal margins is lacking. By focusing on how delivery and burial vary as a function of river discharge this research will forge a unifying link between hydrology and oceanography. Through our event-response sampling, we will develop novel approaches to assimilate the ever-increasing flow of information from real time monitoring stations on land and in the ocean. Lastly, the flux of material through river basins under changing hydroclimatic conditions and land-use practices has widespread societal relevance. Both sediment and particle-associated organic contaminants are common pollutants in US surface waters. Thus, by providing new information on river suspended-sediment and carbon loads, and extending knowledge to rare, high-magnitude events we will shed important light on pollutant-related issues within the study region.