SGER: Fate and Transport of Carbon and sediments During a Mississippi River High Water Event

这项探索性研究小额赠款（SGER）将利用2008年4月发生在密西西比河的10年峰值流量来收集碳和沉积物通量的直接测量数据。特别是，这一罕见的事件为回答以下问题提供了一个理想的机会：1)不同来源的有机碳是如何被河流运输和加工的？2)泛滥的河流如何积聚并将沉积物分配到邻近的湿地？采用两阶段采样方案（船基和陆基）对河流的悬浮负荷、总有机碳、散装有机碳年龄谱、营养物质和水文学进行采样。水声技术将用于确定洪水中河流的速度结构。短寿命的、自然产生的放射性同位素(如：将结合x射线摄影和经典沉积学方法来量化最近的沉积。将收集长岩心，最终将这些速率与长期沉积历史进行比较。鉴于2005年发生在密西西比河三角洲地区的环境破坏，再加上该地区对当前和未来气候变化的脆弱性，本项目解决的问题与社会、政策和决策者以及广泛的环境和工程科学家都高度相关。

This Small Grants for Exploratory Research (SGER) award will take advantage of the ~10-year peak-flow to occur in April, 2008, in the Mississippi River to gather direct measurements of carbon and sediment flux. In particular, this rare event provides an ideal opportunity to answer the following questions: 1) How is organic carbon of varying sources transported and processed by rivers? and 2) How do flooding rivers accumulate and distribute sediments to adjacent wetlands? A two stage sampling program (ship-based and land-based) will be employed to sample the suspended load, total organic carbon, bulk organic carbon age spectra,nutrients, and hydrology of the river during the peak-flow event. Hydro-acoustic techniques will be used to determine the velocity structure of the river in flood. Short-lived, naturally occurring radioisotopes(e.g. 7Be) will be used in combination with x-radiographs and classical sedimentology methods to quantify recent deposition. Long cores will be collected to ultimately compare these rates to long-term sedimentation histories.In light of the environmental destruction that occurred in the Mississippi River delta region in 2005, coupled with the region's vulnerability to current and future climate changes, this project tackles issues that are highly relevant to both society, to policy and decision makers, and to a broad spectrum of environmental and engineering scientists.