Towards a Model of the Biogeochemistry of Continental-Scale River Basins: An Amazon Case Study

里奇研究建议她考虑大型流域的动态，并以亚马逊铆钉系统为例进行测试。本提案要解决的核心问题是，大型河流系统如何获得并随后改变其生物地球化学组成？问题和假设将分为以下几个部分：(1)水系的生物地球化学停留如何受到陆地表面的影响？(2)在水系运输过程中，土地效应是如何改变的？总结的工作假设是，“在河流系统的任何下游节点，一包水中溶解和颗粒生物活性物质的数量和组成是可预测的，作为一组共同过程的产物，这些过程根据上游的相对类型、土壤有机含量和质地、水和停留时间以及洪泛区范围的条件而不同。”为了验证这一假设，研究的目标是：(1)实施和执行一个实地采样计划，该计划将有效地提供来自整个盆地的样本，包括来自主要支流的横断面，以及秘鲁和玻利维亚的源头地区。超滤技术将用于处理各种颗粒和分子大小的水。(2)建立基于水、颗粒和溶解物质通过河网路由的定量模型。这项工作将把我们以前开发的水文和化学模型与我们的新信息结合起来。(3)进行实验，确定陆地对有机质组成的影响。利用建模方法，确定了细颗粒馏分中存在的细有机物质的上界和化学选择性。模拟吸收试验将是流域内主动分区的第三次试验。(4)对颗粒出口的控制将通过泥沙移动和路径的测量和建模进行调查。同位素示踪剂将用于确定物质来源的位置。（5）

Richey Research is proposed her to consider the dynamics ogf large-scale drainage basins, using the Amazon Rivet system as a test case. The central question to be addressed in this proposal is, How does a large river system obtain and subsequently modify its biogeochemical composition? The question and hypothesis will be divided into parts: (1) How is the biogeochemical stay of the river system influenced by the land surfaces? (2) How are the land effects modified during transit through the river system? The summaty working hypothesis is that, "The quantity and composition of dissolved and particulate bioactive materials in a parcel of water at any downstreasm node in the river system is predictable as the product of a common set of processes which occur differentially according to upstream conditions of relative typography, soil organic content and texture, water and residence time, and floodplain extent." To test this hypothesis the research objectives are to: (1) Implement and carry out a field sampling program that will efficiently provide samples from throughout the basin, including from the mainstem, from transects along major tributaries, and into headwater regions of Peru and Bolivia. Ultrafiltration techniques will be used to process water across a spectrum of particle and molecular sizes. (2) Develop a quantitative model based on routing water and particulate and dissolved substances through the rivernetwork. This effort will couple the hydrology and chemistry models we have previously developed with our new information. (3) Conduct experiments to determine terrestial effects on organic matter composition. Using a modeling approach, upper bounds of fine organic material thwt exist in the fine particle fraction will be determined as will the chemical selectivity. Simulated absorption experiments will be the third test for active partioning within the drainage basin. (4) Controls on particulate export will be investigated using measurments and modeling of sediment mobil ization and routing. Isotopic tracers will be used to determine the location of material origin. (5)