Dr. Simkins’ research broadly focuses on past changes in coastal, marine, and glacial environments and the processes that control those changes, primarily using sedimentological and geomorphological archives. For more information and available graduate student positions, visit her research website.
My primary research interests are in the areas of (1) catchment hydrology, focusing on hydrological and geochemical transport processes, and (2) land-atmosphere interaction, including the exchange of water, energy, and gaseous compounds such as carbon dioxide, nitrous oxide, and methane between the terrestrial surface and the atmosphere. I seek to develop an integrated understanding of how the hydrological cycle, vegetation processes, and atmospheric dynamics are linked as well as how these connections are manifest in terms of nutrient cycling and ecosystem function.
My overall research interest is in watershed biogeochemical processes and identifying the hydrologic drivers of those processes. More specifically, my research focuses on the status and trends of stream flow and stream-water quality in response to stressors, including air pollution, climatic variability, and anthropogenic land-use influences.
My research focuses on the chemical quality of surface water and the geochemistry of sediments. Measures are sought for the amount and sources of anthropogenic inputs of both major elements and trace elements into freshwater catchments and estuarine and deltaic depositional sites. Interest has been devoted largely to river and estuarine systems of the temperature zone, but also includes tropical systems, especially in Southeast Asia.
My research focuses on the complex interactions and constraints that govern the evolution of natural landscapes, including surfaces of other planets. This research combines field studies, theory, simulation modeling, and quantitative analysis. Field studies have included evolution of channels in badlands, the natural regime and man’s influence on the Colorado River in the Grand Canyon, and the role of groundwater sapping in erosion of sandstone canyons in the southwest U.S..
My general field of interest is low-temperature aqueous geochemistry, encompassing problems in water-rock interactions, kinetics of geochemical reactions, and evolution of groundwater chemistry in various hydrogeological environments. My research includes elements of field studies, laboratory experimentation, and theoretical modeling. One research project is focused on the fate and transport of bacteria and organic contaminants in groundwater and is a collaborative effort with Messrs. Mills and Hornberger.
My biogeochemical research includes investigations on the natural and anthropogenic controls on chemical cycles at the watershed, regional and global scales. I started first with trace metal biogeochemistry of the coastal ocean, and then expanded to investigations on the increased acidification of the atmosphere, soils and fresh waters. My current research focuses on beneficial and detrimental effects of reactive nitrogen as it cascades between the atmosphere, terrestrial ecosystems and freshwater and marine ecosystems. My most recent work examines how to maximize the use of nitrogen for