High-Resolution Record of Upper Mississippi River Flood Responses to Holocene Climate Change

本研究的总体目标是研究历史上的冲积沉积的上密西西比河（UMR），以推进我们的理解如何气候变化影响的大小和时间的洪水的主要渠道的UMR在西部威斯康星州。这个中部大陆遗址包含了近10，000年来几乎连续的冲积记录，并提供了一个独特的机会来研究这个重要流域的长期和短期极端流量事件的历史。本研究的具体目标是：1）获得高分辨率的记录，以帮助重建全新世洪水在上密西西比河（UMR）的主要和次要渠道：2）定量连接主渠道的洪水制度，从其他研究人员获得的独立的古气候代理;（3）定量分析和对比了气候突变和气候渐变期间UMR系统对极端水文事件的响应; 4）量化洪水水文学对气候变化相对变化的响应（即，更温暖/更湿润、更温暖/更干燥等）。 这些具体目标将通过实地、实验室、统计和模型分析相结合来实现。这项研究很重要，因为极端河流流量的频率或强度的变化有可能对人类社会和自然环境产生重大影响。仪器记录太短，无法充分确定气候变化如何充分影响大型河流系统（如UMR）的水文极端情况。这项研究的结果将有助于我们了解陆地水文系统如何响应全球尺度大气环流的变化。研究结果也有助于理解气候变化与反复出现的极端水文事件之间的关系。

The general objective of this research is to examine the history of alluvial sedimentation of the Upper Mississippi River (UMR) to advance our understanding of how climate variability influences the magnitudes and timing of floods on the main channel of the UMR in western Wisconsin. This mid continent site contains a nearly continuous alluvial record that extends nearly 10,000 years and provides a unique opportunity to examine the history of long- and short-term extreme flow events in this important watershed. The specific goals of this research are to: 1) obtain high-resolution records that can help reconstruct Holocene floods in the main and secondary channels of the Upper Mississippi River (UMR); 2) quantitatively link the flood regime of the main channel to independent paleoclimate proxies obtained from other researchers; 3) quantify and contrast the response of the UMR system to extreme hydrologic events during abrupt climate change and gradual climate change; 4) quantify the response of flood hydrology to the relative changes in climate change (i.e., warmer/wetter, warmer/drier, etc) inferred from proxies. These specific goals will be achieved by a combination of field, laboratory, statistical, and modeling analyses.The research is important because changes in the frequency or intensity of extreme river flows have the potential to produce major impacts on both human society and the natural environment. Instrumental records are too short to adequately determine how climate changes fully influence extremes in flow hydrology on large river systems such as the UMR. Results from this research will help us understanding how terrestrial hydrologic systems respond to changes in global scale atmosphere circulation. The results also should be useful for understanding the relationship between changing climate and recurring extreme hydrologic events.