(EGB) Evaluating the Processes Governing Particle-Reactive Element Transport in an Arctic River System: Coupling Hydrology, Geochemical Tracers, and Hydrologic Models

(EGB) 评估北极河流系统中颗粒反应元素输运的过程：耦合水文、地球化学示踪剂和水文模型

• 批准号: 9807590
• 负责人: Frederick Sayles
• 金额: $ 44.6万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-15 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9807590&HistoricalAwards=false
• 关键词: EGB; Evaluating; Processes; Governing; Particle

9807590SaylesWe propose an interdisciplinary approach for the evaluation of the riverine transport of sediments and particle-associated contaminants that is applicable to many sparsely measured river-dominated coastal systems. To overcome data restrictions and cover large spatial scales, we propose the joint use of geochemical, hydrodynamic, and hydrological data sets together with high-resolution models of transport and geochemical processes. Our objective is to provide basic information on the pathways, dynamics, and controls on transport and depositional environments, and to explore the sensitivity of the system to contaminant- loading and accumulation. A very important aspect of the study is the deliberate design of the approach to use the often-minimal monitoring network on river systems together with limited field observations. We propose to focus our study on the Ob River, one of the four largest rivers flowing into the Arctic Ocean. It is representative of large Arctic rivers in many respects, but is unique in a way that adds greatly to its utility for the present study. The Ob basin has been the site of the bulk of the nuclear weapons production and development program of the former Soviet Union. As a result of releases from thee facilities, a variety of tracers has been introduced, over the past 50 years, into the river system at known point-sources providing unique opportunities for studying pollutant transfer rates and mechanism, as well as basic sediment transport and deposition within this large arctic river system. We will use a two-dimensional hydrodynamic model with sediment-transport and geochemical interaction submodels to interpolate between river data sets. In a statistical sense, we will evaluate how the fate of the particles and associated tracers is governed by the geochemistry, the hydrology, the geometry of the river configuration, and the physical processes that must be responsive to the river geometry, flow, and the physics of sediment transport. The links between the geochemical data derived from the sediment cores, the historical hydrologic data, and the models will be established through developing detailed chronologies for the cores. This chronology then would be used to relate changes in accumulation rates and sediment characteristics in space and in time to multiyear changes in hydrologic conditions and model predictions.Recently obtained data from Ob above its confluence with the Irtysh provide strong confirmation of the utility of studies in this river basin. The sediments from this river contain uniques isotopic signatures that effectively "tag" its sediments. One isotopic ratio, 240Pu/239Pu, is ~constant over the past 50 years providing a label to identify these sediments in mixtures down stream. A second tracer, 237Np, varies strongly over times, by up to an order of magnitude, providing a time varying signal for use in estimating transport and deposition rates. Such unique signatures are ideal for meeting the goals proposed here. This proposal was submitted to the EGB Program and is being jointly funded by:1. Division of CTS (Arndt) and (Roco)2. Division of INT - (Dudka)3. Division of OPP - (Ledbetter)4. Division of OCE - (Buesseler)

我们提出了一种跨学科的方法来评估沉积物和颗粒相关污染物的河流运输，该方法适用于许多稀疏测量的河流主导的沿海系统。为了克服数据限制和覆盖大空间尺度，我们建议联合使用地球化学、水动力和水文数据集以及高分辨率的运输和地球化学过程模型。我们的目标是提供关于运输和沉积环境的途径、动力学和控制的基本信息，并探索系统对污染物负荷和积累的敏感性。这项研究的一个非常重要的方面是精心设计方法，利用通常最小的河流系统监测网络和有限的实地观测。我们建议将研究重点放在流入北冰洋的四大河流之一的鄂毕河上。它在许多方面都是北极大河的代表，但在某种程度上是独一无二的，这极大地增加了它在本研究中的实用性。Ob盆地一直是前苏联大部分核武器生产和发展计划的所在地。在过去的50年里，由于三个设施的释放，各种示踪剂已经被引入到河流系统中，在已知的点源处，为研究这一大型北极河流系统中的污染物转移速率和机制，以及基本的沉积物运输和沉积提供了独特的机会。我们将使用二维水动力模型与泥沙输运和地球化学相互作用子模型在河流数据集之间进行插值。在统计意义上，我们将评估颗粒和相关示踪剂的命运是如何由地球化学、水文学、河流配置的几何形状以及必须响应河流几何形状、流量和沉积物运输物理过程的物理过程所控制的。沉积物岩心的地球化学数据、历史水文数据和模型之间的联系将通过开发岩心的详细年表来建立。然后，这个年代学将用于将空间和时间上的积累速率和沉积物特征的变化与水文条件和模式预测的多年变化联系起来。最近从鄂毕河与额尔齐斯河汇合处获得的数据有力地证实了在该流域进行研究的实用性。这条河的沉积物含有独特的同位素特征，可以有效地“标记”其沉积物。其中一个同位素比值240Pu/239Pu在过去的50年里保持不变，这为在下游的混合物中识别这些沉积物提供了一个标签。第二种示踪剂237Np随时间变化很大，可达一个数量级，为估计运输和沉积速率提供了一个随时间变化的信号。这种独特的签名是实现本文提出的目标的理想选择。该提案已提交给EGB计划，并由以下机构共同资助：CTS （Arndt）和（Roco）分部INT - (Dudka)部门3。OPP - (Ledbetter)事业部OCE部-（经销商）