MAPPING WETLANDS: A COMPARISON OF TWO DIFFERENT APPROACHES FOR NEW BRUNSWICK, CANADA

• Published in: Wetlands (Wilmington, N.C.) Vol. 27; no. 4; pp. 846 - 854
• Main Authors: Murphy, Paul N. C., Ogilvie, Jae, Connor, Kevin, Arp, Paul A.
• Format: Journal Article
• Language: English
• Published: 1313 Dolley Madison Boulevard, Suite 402, McLean, Virginia, USA 22101 The Society of Wetland Scientists 01.12.2007; Springer Nature B.V
• Subjects: aerial photography; Biodiversity; continuous field models; depth-to-water maps; Digital Elevation Models; Ecological function; ecoregions; Freshwater; geographic information systems; GIS; image analysis; methodology; REGULAR SUBMISSIONS; Riparian land; riparian zones; soil mapping; soil water content; soil wetness index; Spatial data; spatial distribution; topographic modeling; Topography; Water depth; water table; watershed management; Wetland management; Wetlands; New Brunswick; Canada; Canada, New Brunswick
• ISSN: 0277-5212; 1943-6246
• DOI: 10.1672/0277-5212(2007)27[846:MWACOT]2.0.CO;2

Wetlands have an important role in ecosystem function and biodiversity. Effective management of wetlands requires accurate and comprehensive spatial information on location, size, classification, and connectivity in the landscape. Using a GIS, two provincial wetland maps were compared with regard to their areal correspondence across different ecoregions of New Brunswick. The first consisted of discrete wetland units (vector data) derived from aerial photo interpretation. The second consisted of wet areas modeled by a newly developed depth-to-water index with continuous coverage across the landscape (raster data). This index was derived from a digital elevation model and hydrographic data. The relative advantages and disadvantages of the two approaches were assessed. The two maps were generally consistent with most discrete wetland areas (51%–67 %) embedded in the 0–10 cm depth-to-water class, verifying the continuous modeling approach. The continuous model identified a larger wetland area. Much of this additional area consisted of riparian zones and numerous small wetlands (< 1 ha) that were not captured by aerial photo interpretation. Unlike the discrete map, the continuous model showed the hydrological connectivity of wetlands across the landscape. Both approaches revealed that topography was a major control on wetland distribution between ecoregions, with more wetland in ecoregions with flatter topography.