Automated Techniques to Identify Lost and Restorable Wetlands in the Prairie Pothole Region

Abstract

Wetland loss in the Prairie Pothole Region has been substantial, and automated techniques to estimate wetland loss and identify priority wetlands for restoration are crucial if important ecosystem services provided by wetlands are to be maintained. A suite of automated methods was developed to establish a historical wetland inventory and to identify the proportion of permanently and temporarily lost wetlands in a prairie pothole watershed in Alberta, Canada. A power law analysis of area vs. frequency of historical wetlands provided estimates of permanently lost wetlands. Combining the historical wetland inventory with an inventory of existing wetlands provided estimates of temporarily lost wetlands. 22,204 historical wetlands comprising 12,431 ha were estimated in the watershed. Permanently lost wetland number and area were estimated as 11.1% and 0.6% respectively, and temporarily lost wetland number and area were estimated as 61.1% and 78.3% respectively. Existing wetlands represented only 27.8% of the total historical number and 21.2% of the total historical area. 1,588 ditch-drained (relatively easy restore) wetlands were identified from the inventory of temporarily lost wetlands using digital terrain analysis, representing a potential recovery of 7.2% of the historical wetlands by number and 9.8% by area.