Each year, massive amounts of organic carbon, in the form of dissolved molecules, are transported to the oceans of the world by rivers. The source of most of that carbon is the upper layer of soils within small watersheds, and the movement of water through soils controls organic carbon delivery from the landscape to streams. Standing on the streambank, the investigators look both upslope and downstream, focusing on the interactions of water movement and organic carbon supply, investigating processes within the hillslope soils, individual stream reaches, and the entire river network. This proposal will integrate dynamic mathematical models that describe organic carbon movement, transformation, quantity and quality in terrestrial and aquatic environments and will generate the first model that links the water cycle and the carbon cycle of river catchments.
The research will have important outcomes for the management of drinking water resources, where watersheds are recognized as the first stage of treatment. Additionally, an increased understanding of the dynamics of organic molecules in water will provide valuable information about the fate and transport of potentially harmful anthropogenic compounds that stick to and are transported with those naturally occurring molecules. Lastly, in developing an understanding of the cumulative role of small streams in the carbon cycle of large rivers, the researchers will contribute information concerning the value of headwater streams to society.
