Factors Influencing Spatial and Temporal Patterns of Metal Deposition to Inland LakesEPA Grant Number: U915766
Title: Factors Influencing Spatial and Temporal Patterns of Metal Deposition to Inland Lakes
Investigators: Yohn (Simpson), Sharon J.
Institution: Michigan State University
EPA Project Officer: Michaud, Jayne
Project Period: August 1, 2000 through August 1, 2003
Project Amount: $91,973
RFA: STAR Graduate Fellowships (2000) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Geology , Ecological Indicators/Assessment/Restoration
The objectives of this research project are to: (1) investigate how the spatial and temporal patterns of metal accumulation rates to inland lakes have changed over time, and (2) determine how the importance of different sources and processes controlling the accumulation rates of different metals to inland lakes have changed over time.
As part of the Michigan Department of Environmental Quality's long-term monitoring program, sediment cores will be collected from multiple lakes throughout Michigan, dated with 210-Pb and 137-Cs, and analyzed for a suite of metals (Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Ba, Pb, U, P, Sn, and Li). It is this multi-element approach that will make it possible to differentiate the influences of different sources and processes. Accumulation rates will be determined for each metal over time within each lake. Within each lake, the elements will be grouped by correlation as a measure of source (e.g., anthropogenic elements, terrestrial elements, elements influenced by trophic status). One element that is representative of each group will be chosen for further statistical analysis. Spatial trends of each of these chosen elements will be examined at certain time intervals. To quantify the effects of different factors influencing the accumulation rates of the elements of interest, a stepwise multiple regression model will be created with each chosen element at each time interval and several factors. The factors are indicators of processes or sources that will influence anthropogenic input, amount of erosion, and trophic status of the lake. Some possible factors include: population density, land use in the watershed, soil type, average slope in the watershed, average temperature, and rainfall. The change in relative importance of the different factors will be examined over time to evaluate how sources and processes have changed.
To reduce the amount of contaminants entering a lake, it is necessary to understand what sources and processes are influencing accumulation rates. Sediment chronologies from multiple inland lakes can provide information on the importance of factors such as land use, population density, and atmospheric deposition on the rate of contaminant input, and how the importance of these factors has changed over time. This information can help policy makers by indicating which sources of contamination are the most significant, and also help property owners within the watershed understand their influence on the health of the lake.