National wetland map 5 confidence map

The confidence map was compiled to identify areas where wetland extent and hydrogeomorphic (HGM) units (which contributed to defining the inland wetland ecosystem types together with the regional setting) attained at a higher level of certainty compared to other areas. Higher levels of certainty are associated [code 5 in field Confidence_nr] with areas that have been visited in-field by a wetland specialist(s) over multiple seasons and cycles of the wetland hydroperiod, and are therefore more accurately represented in the dataset. Codes 4 to 1 indicate lower levels of confidence that the extent and HGM unit are represented well.

For the purpose of the SAIIAE, higher levels of certainty are associated with areas that have been visited in-field by a wetland specialist(s) over multiple seasons and cycles of the hydroperiod of a wetland, and are therefore likely more accurately represented in the dataset. Accuracy reflects the degree to which the spatial boundaries and/or attributes of the wetlands match those in the real world. A higher confidence score would imply an increase in accuracy, assuming that the spatial boundaries of a wetland had been informed by water, soil and vegetation indicators, and recorded with differential GPSs. Low confidence scores would imply the inverse.

The confidence rating map should always be consulted to assess whether the NWM5 is fit for purpose. The confidence of rivers, estuarine and coastal ecosystems is not reflected in this confidence map. In general, areas mapped as Low confidence may have a 50% omission error, though the commission error may have been reduced to < 10% compared to the previous versions of the NWMs. The appropriate scale of use would be 1:50 000. Where the confidence rating is Low to Medium, Medium and Medium to High, the omission error was estimated to be < 30% and the commission error < 10%.