ABSTRACT
Wetlands are vital ecosystems for planetary and human health as they provide essential ecological services such as purifi cation of water, cycling of nutrients, and recharge of ground water and also provide wetland products such as fi sh, rice, and some forest resources.[1,2] Wetlands are often rich in biodiversity and are important sites for biogeochemical processes such as the production of methane and nitrous oxide as well as fi xation of carbon and nitrogen.[1,3,4] Historically, wetlands were considered a hindrance to development and were modifi ed following dredge and fi ll operations, pollutant runoff, eutrophication, and fragmentation by roads.[5] The key role of wetlands in sustaining ecological health has only been recognized recently prompting their monitoring and conservation.[5,6] Over the last four decades, remote sensing has served as an important and powerful tool for mapping, monitoring, and characterization of wetland ecosystems. All types of wetlands including inland freshwater marshes, coastal tidal marshes, mangrove ecosystems, and forested wetlands or swaps have been studied using remotely sensed data available at different spatial, spectral, and temporal resolutions. This entry provides an overview of the data, methods, application areas, and challenges of remote sensing of wetlands.
