Upper Midwest Environmental Sciences Center

Home About Director's Overview History of Center Employee Directory Map to Center Partners State Field Stations Lake City, Minnesota La Crosse, Wisconsin Bellevue, Iowa Great Rivers, Illinois Open River, Missouri Havana, Illinois Field Station Directory Science Programs Aquatic Ecosystem Health River Ecology Long Term Resource Monitoring Wildlife Ecology Geospatial Sciences and Technology Science Initiatives Science Topics Data and Tools Publications Software Multimedia News

The Long Term Resource Monitoring Program An element of the Upper Mississippi River Restoration - Environmental Management Program Water Quality

Table 2.

Calendar used for stratified random sampling in the Long Term Resource Monitoring Program. The primary sampling period begins on a Monday and extends over the next 14 days exclusive of weekends. A third week may be used if necessitated by urgent circumstances, safety considerations, or equipment failure. The SRS sampling schedule takes second priority if it conflicts with fixed-site sampling.

Sampling period	Start date	Rationale
Spring	Monday of last full work week in April	Period of maximum discharge in the Upper Mississippi River
Summer	Monday of last full work week in July	Late summer conditions, typically low-flow period of maximal water temperature, minimal oxygen
Fall	Monday of second full work week in October	Low-flow period after aquatic vegetation die-back and before ice formation. Period of maximum waterfowl migration. Moved forward a week in 1996 and 1997 to avoid conflict with waterfowl hunters.
Winter	Monday of last full work week in January	Period of maximal ice and snow cover, lowest water temperatures, and minimal oxygen concentration.

Page Last Modified: April 17, 2018