Upper Midwest Environmental Sciences Center
| 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. |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://www.umesc.usgs.gov/reports_publications/ltrmp/water/tables/table2.html
Page Contact Information: Contacting the Upper Midwest Environmental Sciences Center
Page Last Modified:
December 31, 2012
