Stream Catchment Interaction Controlling DOC Concentration and Composition under Varying Flow Regimes in Rocky Mountain Streams

9628368在许多集水-溪流系统中，溶解有机物(DOM)的浓度和组成是一个重要的水质特性。由DOM相互作用控制的过程的例子有：1)DOM腐殖酸部分与痕量金属的络合作用，它控制着痕量金属的传输和生物可利用性；2)增加疏水性有机污染物的溶解度；3)在水处理过程中，由于氯与DOM各组分之间的相互作用，在饮用水中形成三卤代甲烷；以及4)DOM吸收可见光和紫外线辐射并产生光产物。DOM还可以通过影响水生生态系统的内部过程，如光合作用和异养活动，对水质产生间接影响。在这项建议中，我们提出了一项研究计划，旨在研究河流中的过程及其与流域过程的相互作用，以确定落基山脉河流中DOC的数量和质量的时空模式。研究任务将包括向河流段添加富含DOC的水以量化潜流带中的相互作用、现场监测以确定河流渠道和山坡上的天气空间格局、DOC的数量和组成，以及扩展数学模型以解释结果。对内流过程的研究将包括继续评估近流和集水区范围的过程的作用。

9628368 Hornberger In many catchment-stream systems, the concentration and composition of dissolved organic material (DOM) is a critical water quality characteristic. Examples of processes controlled by DOM interactions are: 1) complexation of trace metals by the humic fractions of DOM which control both trace metal transport and bioavailibility; 2) enhancement of the solubility of hydrophobic organic contaminants; 3) formation of trihalomethanes in drinking water as a result of interactions between Chlorine and components of the DOM during water treatment; and 4) absorption of visible and UV radiation by DOM and generation of photoproducts. The DOM also can have indirect effects on water quality by influencing internal processes of aquatic ecosystems, e.g., photosynthesis and heterotrophic activity. In this proposal, we advance a plan of study to investigate in-stream processes and their interaction with catchment processes in determining the spatial and temporal patterns of quantity and quality of DOC in streams in the Rocky Mountains. The research tasks will include experimental additions of DOC-enriched water to stream segments to quantify interactions in the hyporheic zone, field monitoring to deermine synoptic spatial patterns along stream channels and in hillslope lysimeters of amounts and composition of DOC, and the extension of mathematical models to interpret the results. Studies of the in-stream processes will include continuing assessment of the roles of near-stream and catchment-scale processes.