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

小行星9628368 在许多集水河流系统中，溶解性有机物（DOM）的浓度和组成是一个关键的水质特征。 受DOM相互作用控制的过程包括：1）DOM中腐殖酸组分对微量金属的络合作用，控制微量金属的迁移和生物有效性; 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组分之间的相互作用，在饮用水中形成三卤甲烷; 4）DOM对可见光和紫外线的吸收及光产物的产生。 DOM还可以通过影响水生生态系统的内部过程对水质产生间接影响，例如，光合作用和异养活性。 在这个建议中，我们提出了一个研究计划，以调查流过程及其相互作用与集水过程中确定的空间和时间模式的DOC的数量和质量的流在落基山脉。 研究任务将包括实验增加DOC富集的水流段，以量化的相互作用，在hyporheic区，现场监测，以确定天气的空间模式沿着河道和山坡蒸渗仪的DOC的数量和组成，并扩展数学模型解释的结果。 对河流内过程的研究将包括继续评估近河和集水规模过程的作用。

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.