Tracing Fine Sediment Transport in Fluvial Systems Using Fallout Radionuclides

9814814 Matisoff尽管我们了解沉积物和沉积物污染物的总体路径，但我们对它们通过排水网络和接收体的过境时间了解甚少。 本项目的目标是开发一种创新但广泛适用的工具，以研究景观细泥沙的侵蚀机制和细悬浮颗粒物在渠道中的传输特性。 具体而言，我们的目标是回答悬浮泥沙的来源问题（是来自片蚀，细沟侵蚀，银行侵蚀，或再悬浮的底部沉积物？）;来自流域的细沉积物的输送率（即，从地貌侵蚀并输送到接收沃茨的沉积物比例，或仅部分输送并停留在地貌上或河床中的沉积物比例;从土壤覆盖地貌新输送的悬浮沉积物与从河床再悬浮的悬浮沉积物的比例;细颗粒物的过境距离;颗粒物的停留时间;以及来自流域的细颗粒流量。 我们将采用我们开发的一种新技术，使用沉降物放射性核素（7 Be，137 Cs和210 Pb）作为溪流悬浮的细沉积物的示踪剂。这项为期两年的研究将集中在怀俄明州和蒙大拿州的黄石河流域。 在第一年，我们将解决动力学的跟踪和积雪，土壤，底部沉积物和悬浮沉积物的放射性核素签名的特性。 在第二年，我们将在一个融雪驱动的水文过程中，描述900公里范围内细沉积物的来源和运输。 实验设计包括在排水网络的不同位置收集降水、土芯、河漫滩沉积物、渠道底部沉积物和悬浮沉积物样品;自然存在的短寿命（7 Be）和长寿命样品的伽马能谱（137 Cs 210 Pb）沉降物放射性核素和其他重要放射性核素标记（214 Bi，40 K）吸附在沉积物上，提供了不同时间尺度上沉积物运动的示踪剂，示踪了1950年研究区某高地源区释放的尾矿的运动; 9814814 Matisoff尽管我们了解沉积物和沉积物污染物的总体路径，但我们对它们通过排水网络和接收体的过境时间知之甚少。 本项目的目标是开发一种创新但广泛适用的工具，以研究景观细泥沙的侵蚀机制和细悬浮颗粒物在渠道中的传输特性。 具体而言，我们的目标是回答悬浮泥沙的来源问题（是来自片蚀，细沟侵蚀，银行侵蚀，或再悬浮的底部沉积物？）;来自流域的细沉积物的输送率（即，从地貌侵蚀并输送到接收沃茨的沉积物比例，或仅部分输送并停留在地貌上或河床中的沉积物比例;从土壤覆盖地貌新输送的悬浮沉积物与从河床再悬浮的悬浮沉积物的比例;细颗粒物的过境距离;颗粒物的停留时间;以及来自流域的细颗粒流量。 我们将采用我们开发的一种新技术，使用沉降物放射性核素（'Be，117 CS和21 OPb）作为溪流悬浮的细沉积物的示踪剂。这项为期两年的研究将集中在怀俄明州和蒙大拿州的黄石河流域。 在第一年，我们将解决动力学的跟踪和积雪，土壤，底部沉积物和悬浮沉积物的放射性核素签名的特性。 在第二年，我们将在一个融雪驱动的水文过程中，描述900公里范围内细沉积物的来源和运输。 实验设计包括在排水网络的不同位置收集降水、土芯、河漫滩沉积物、渠道底部沉积物和悬浮沉积物样品;自然存在的短寿命（'Be）和长寿命样品的γ能谱（117 Cs anCf 2 'OPb）沉降物放射性核素和其他重要放射性核素标记（214 Bi，@K）吸附在沉积物上，提供了不同时间尺度上沉积物运动的示踪，追踪了1950年研究区一个高地源区释放的尾矿的运动，分析了颗粒的大小和浓度;以及波动运动学和质量平衡建模。

9814814MatisoffDespite our understanding of the gross paths taken by sediments and sediment-bound pollutants, we have a poor knowledge of the transit time for their passage through the drainage network and to receiving bodies. The goal of this project is to develop an innovative but broadly applicable tool to investigate the erosion mechanisms of fine sediment from the landscape and the transport characteristics of fine suspended particulates in channels. Specifically, we aim to answer questions on the the source of the suspended sediment (Is it from sheet erosion, rill erosion, bank erosion, or resuspension of bottom sediments?); the delivery ratios of fine sediment from the watershed (i.e., the proportion of sediment that is eroded from the landscape and delivered to the receiving waters or the proportion that is transported only part way and resides on the landscape or in the streambed); the proportions of suspended sediment that is newly delivered from the soil mantled landscape versus resuspended from the bed; the transit distance of fine particulates; the residence time of particulates; and the flux of fines from the watershed. We will employ a novel technique we have developed that uses fallout radionuclides ( 7Be , 137Cs, and 210Pb ) as tracers of fine sediments suspended by streamflow.The two-year study will be focused in the Yellowstone River watershed in Wyoming and Montana. During the first year we will address the kinetics of the tracing and the characterization of the radionuclide signature of the snowpack, soils, bottom sediment, and suspended sediment. During the second year we will characterize the sources and transport of fine sediment over a distance of 900 km during a snowmelt-driven hydrograph. The experimental design includes collection of precipitation, soil cores, floodplain sediment, channel bottom sediment, and suspended sediment samples at various locations in the drainage networks; gamma spectroscopy of samples for naturallyoccurring short-lived (7Be) and lonaer-lived ( 137Cs 210 Pb) fallout radionuclides and other important radionuclide tags (214 Bi, 40K) that adsorb to sediment providing tracers of sediment movement over different time scales; tracing the movement of mine tailings that were released from an upland source area in the study area in 1950; analyses of particle sizes and concentrations; and wave kinematic and mass balance modeling.9814814MatisoffDespite our understanding of the gross paths taken by sediments and sediment-bound pollutants, we have a poor knowledge of the transit time for their passage through the drainage network and to receiving bodies. The goal of this project is to develop an innovative but broadly applicable tool to investigate the erosion mechanisms of fine sediment from the landscape and the transport characteristics of fine suspended particulates in channels. Specifically, we aim to answer questions on the the source of the suspended sediment (Is it from sheet erosion, rill erosion, bank erosion, or resuspension of bottom sediments?); the delivery ratios of fine sediment from the watershed (i.e., the proportion of sediment that is eroded from the landscape and delivered to the receiving waters or the proportion that is transported only part way and resides on the landscape or in the streambed); the proportions of suspended sediment that is newly delivered from the soil mantled landscape versus resuspended from the bed; the transit distance of fine particulates; the residence time of particulates; and the flux of fines from the watershed. We will employ a novel technique we have developed that uses fallout radionuclides ('Be, 117CS , and 21 OPb) as tracers of fine sediments suspended by streamflow.The two-year study will be focused in the Yellowstone River watershed in Wyoming and Montana. During the first year we will address the kinetics of the tracing and the characterization of the radionuclide signature of the snowpack, soils, bottom sediment, and suspended sediment. During the second year we will characterize the sources and transport of fine sediment over a distance of 900 km during a snowmelt-driven hydrograph. The experimental design includes collection of precipitation, soil cores, floodplain sediment, channel bottom sediment, and suspended sediment samples at various locations in the drainage networks; gamma spectroscopy of samples for naturallyoccurring short-lived ('Be) and lonaer-lived (117 Cs anCf2 'OPb) fallout radionuclides and other important radionuclide tags (214 Bi, @K) that adsorb to sediment providing tracers of sediment movement over different time scales; tracing the movement of mine tailings that were released from an upland source area in the study area in 1950; analyses of particle sizes and concentrations; and wave kinematic and mass balance modeling.