Remote Sensing for Environmental Monitoring and Change Detection (Proceedings of Symposium HS3007 at IUGG2007, Perugia, July 2007). IAHS Publ. 316, 2007. Copyright © 2007 IAHS Press 100 Mapping and monitoring wetlands using airborne multispectral imagery CHRISTOPHER M. U. NEALE 1 , DENNIS WENGER 2 , HARIKISHAN JAYANTHI 1 & FAYEK FARAG 3 1 Department of Biological and Irrigation Engineering, Utah State University, Logan, Utah 84322-4105, USA cneale@cc.usu.edu 2 Frontier Corporation USA, Providence, Utah 84332, USA 3 National Water Research Center Strategic Research Unit, El-Qanatir, Qalyoubia, Egypt Abstract Wetland areas in the semiarid west of the United States play an important eco-hydrological role. The size, location and function of wetlands are affected by numerous factors such as variations in water availability, water quality, geomorphic characteristics and anthropogenic factors such as runoff from irrigation systems, or discharge of urban effluents. Typically, wetland vegetation occurs in patches of variable size and plant species composition, requiring high-resolution imagery to accurately identify distribution and extent of the different wetland habitat types when mapping these complex systems. Airborne multispectral digital imaging offers several advantages, including cost-effectiveness and ability to resolve wetland features ranging in size from a few meters to hundreds of hectares. This paper describes the mapping of wetland habitats within the Great Salt Lake Ecosystem using high resolution multispectral imagery (1-m pixels). Image classification was based on super- vised signature extraction supported by comprehensive ground truth. An error analysis was conducted using independent ground truth data, and the resulting classification accuracy for the final wetland resource map was 92%. Key words airborne multispectral digital imaging; wetland mapping INTRODUCTION The Great Salt Lake Wetlands Ecosystem (GSLWE) provides critical breeding and staging areas for millions of migratory birds travelling the Pacific and Central Flyways. These wetlands are being rapidly degraded because of rapid urbanization along the Wasatch Front and lack of integrated conservation planning at the municipal (i.e. city) level. Wetlands play an important role in the support and sustenance of aquatic life in and around the Great Salt Lake. Loss in the abundance, distribution and condition of wetlands can not only adversely affect wetland-dependent migratory birds and other wildlife, but can also affect water quality and the sustainability of aquatic life in receiving waters (e.g. the Great Salt Lake and its freshwater tributaries). Wetlands play an important role in regulating water quality and providing habitat for numerous species. In the semiarid western United States these systems are particularly fragile and subject to fluctuations in the hydrological cycle. Many wetland areas have resulted or have been augmented by decades of irrigation runoff. The Wasatch Front borders the GSLWE and is the most populated region in the State of Utah. The rapid urban growth and development experienced over the past decade has resulted in the inadvertent destruction, fragmentation, and alteration of