Minnesota comprehensive wetland assessment monitoring and mapping strategy
It is a policy of the State of Minnesota to achieve “no net loss” and to increase the quantity, quality and biological diversity of wetlands in the state (M.S. 103A.201). Efforts to assess wetland status and trends in Minnesota were found to be inadequate. The Minnesota Comprehensive Wetland Assessment, Monitoring and Mapping Strategy (CWAMMS) defined a framework for measuring progress toward this policy.
The overall goal of the CWAMMS was to develop a broadly understood, scientifically sound strategy for monitoring and assessing status and trends in wetland quantity and quality statewide. To meet this goal three complementary approaches were recommended:
- Develop an integrated, geo-referenced, online accounting system for wetland permitting and conservation activities
- Random sample survey plots
- Update the National Wetland Inventory in Minnesota
Fact sheet summary of the CWAMMS as of January 2006- Fact sheet summary of the CWAMMS as of January 2005
Random sample survey — Minnesota Comprehensive Wetland Assessment Monitoring and Mapping Strategy
The Comprehensive Wetland Assessment Monitoring and Mapping Strategy was developed by these partners:
- Board of Water and Soil Resources
- Minnesota Department of Agriculture
- Department of Natural Resources
- Minnesota Pollution Control Agency
- U.S. Fish and Wildlife Service
Minnesota initiated a statewide random survey in the spring of 2006 to track trends in wetland quantity. The DNR Resource Assessment Program and the US EPA Environmental Monitoring and Assessment Program assisted with the statistical design of the survey [link to the pdf copy of the final RAP design]. Color aerial photographic imagery of 1,830 randomly selected 1-sq.-mile plots was initially acquired and wetlands within these sample plots were mapped from this imagery. Similar imagery will be acquired and interpreted each year in 250 “Common” plots and every three years in 1,580 “Panel” plots. Following completion of the first three-year cycle, wetland quantity results will be reported, and establish “baseline” conditions. Repeating panels 1-3 in future cycles will allow comparisons with this baseline to determine whether wetland quantity in the state is changing.
A companion survey program to assess regional trends in wetland quality or “health” is planned to begin in 2007. A main component of this survey will be the utilization of indicators developed by the MPCA Biological Monitoring Unit and possibly other methods to assess the condition of depressional wetlands mapped as part of the quantity survey.
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Status and Trends of Wetlands in Minnesota — Depressional Wetland Quality Baseline (wq-bwm1-06) - A Comprehensive Wetland Assessment, Monitoring, and Mapping Strategy for Minnesota (file size = 4 MB)
- Survey Design Factors for Wetland Monitoring
- Survey Design of Minnesota's Depressional Wetland Quality Assessment (November 2007)
Figure 1. Location of statewide random sample survey plots, including annual and panel plots
PDF file of Wetland Survey Map
Minnesota Integrated Wetland Accounting System
A geo-referenced online permitting and accounting system will enable viewing wetland permitting information in real time and allow querying of permitting and related regulatory results by various geographic areas and will improve overall accounting of wetland protection programs
Initial work for phase 1 (wetland permitting actions) of the online wetland accounting system is being led by the Minnesota Board of Water and Soil Resources in collaboration with the Department of Natural Resources and the Minnesota Pollution Control Agency. This planning phase is expected to be completed by September 2007.
Updating the Minnesota National Wetland Inventory
Original MN NWI Imagery VintageMinnesota’s first-generation NWI mostly originates from imagery acquired in the mid 1980s. Wetlands were mapped using 1970s imagery in a small part of NW MN and a large region in NE MN.
An updated inventory will serve as a valuable resource to improve wetland protection.
Wetland inventory data is used for many purposes by many government and private enterprises. A consortium of local, state and federal government entities along with nonprofit organizations and private business working together may be able to share the cost of updating Minnesota’s NWI.
Updating the NWI could be done most cost effectively using a combination of traditional Color infra-red (CIR) imagery along with new sensors. However, the new technologies must be further evaluated to find the most accurate and cost-effective approach to locate and map wetlands.
Pilot NWI Update AreasWetland mapping is typically done with spring leaf-off imagery. This is particularly critical in the forested regions of Minnesota where a clear view of ground features is obscured by tree canopies. Finding small temporary wetlands under the forest canopy will likely always be a significant challenge.
The U.S. Fish and Wildlife Service (USFWS), in cooperation with Minnesota Natural Resource agencies is testing the effectiveness of newer remote sensing, image processing, and mapping technologies in several wetland mapping pilot projects. In one pilot project near Duluth the USFWS used fall CIR imagery and a limited coverage of spring CIR imagery. Nearly four times more wetlands were mapped using fall CIR imagery compared with the wetland area mapped in the first-generation NWI. This difference is mostly attributable to the larger scale of the current imagery compared with the 1:000 B&W imagery in the first-generation NWI. These results support the potential to effectively use imagery collected for other program purposes such as FIA, which typically use CIR imagery but from a different season.
