Predicting Water Quality for Michigan Inland Lakes

Predicting Water Quality for Michigan Inland Lakes

Overview

The U.S. Geological Survey (USGS) in cooperation with the Michigan Department of Environmental Quality (MDEQ) has been monitoring the quality of inland lakes in Michigan through the Lake Water Quality Assessment monitoring program. However, only a portion of Michigan’s inland lakes can be conventionally sampled each year. A technique was used by the USGS, modeled after Olmanson and others (2001), in cooperation with the MDEQ that uses satellite remote sensing to predict water quality in inland lakes greater than 25 acres. Carlson’s Trohpic State Index (TSI) was used to evaluate the quality of Michigan inland lakes.

Remote Sensing webpages

Follow the links located on the left side of your computer screen under Remote Sensing to navigate the webpages. Process is a simplified explanation of predicting water quality by relating satellite imagery and existing water quality measurements. Report connects you to a link of a report published in 2004 outlining the process in greater detail. Fact Sheet summarizes the process, describes trophic state index, secchi-disk transparency, and Chlorophyll a, and outlines when and where predictions are available. Links is a list of website links to other states with programs to predict water quality. References is a list of references accessed to create the remote sensing program for Michigan. Finally, Downloadable Data/Metadata is a link to an ftp website for data download.

Internet Mapping Service (IMS) interactive website

This information is now available at an Internet Mapping Service (IMS) interactive website. Available online are statewide layers with predicted Secchi-disk and corresponding trophic state index (TSI) values for Michigan inland lakes from years 2003-2006 (2005 layer) by lake average, and by 30-meter pixels (which can demonstrate intra lake variability). Also available are predicted Chlorophyll a and corresponding trophic state index values for Michigan inland lakes from 2004. For more details of the available layers and newly added layers, click here. For a description of how to use the tools on the IMS interactive website click here. Both of the above links can also be accessed from the IMS interactive website.

Limnology links

Understanding Lake Data

by Byron Shaw, Christine Mechenich, and Lowell Klessig

This guide was written to help people understand information about lake water quality and to interpret lake data. Each lake possesses a unique "personality," or set of physical and chemical characteristics which may change over time. Lakes exhibit chemical changes on a daily basis while other changes, such as plant and algae growth, occur seasonally.

Year-to-year changes in a lake are common because surface runoff, groundwater inflow, precipitation, temperature and sunlight vary. For example, the loss of dissolved oxygen can destroy a lake's fish population, but may improve water clarity. Eliminating fish allows algae-eating zooplankton (microscopic animals) to increase, which might reduce algae populations. Because of changes like these, data from several years are needed to show whether a lake is experiencing significant changes in water quality.

This publication explains the physical and chemical compositions of different types of lakes. It covers lakes' nutrient status (trophic condition), and their susceptibility to acid rain. It discusses toxic metals that accumulate in fish and tells how to use general water chemistry principles to document potential changes in water quality. A glossary of technical terms is included to help the reader understand the language used in the study of lakes (limnology).

http://www.dnr.state.wi.us/org/water/fhp/lakes/under/index.htm

Understanding: Lake Ecology Primer

Limnology is the study of fresh or saline waters contained within continental boundaries. Limnology and the closely related science of oceanography together cover all aquatic ecosystems. Although many limnologists are freshwater ecologists, physical, chemical, geological, and engineering limnologists all participate in this branch of science. Limnology covers lakes, ponds, reservoirs, streams, rivers, wetlands, and estuaries, while oceanography covers the open sea. Limnology evolved into a distinct science only in the past two centuries, when improvements in microscopes, the invention of the silk plankton net, and improvements in the thermometer combined to show that lakes are complex ecological systems with distinct structures.

http://waterontheweb.org/under/lakeecology/index.html