Wetlands are among the most productive areas of the planet, but they are also among the most endangered. Indeed, because of their high productivity, they are extremely rich in biodiversity (fauna and flora) and provide a large number of services for people, called ‘ecosystem services’, divided into three categories: regulating services, supporting services, and cultural services. Many ecosystem services are related to wetlands, such as: flood protection, climate change mitigation, freshwater provision, and public involvement for recreation and tourism purposes (Burkhard et al., 2014).
Remote sensing for monitoring and conservation
Despite these proven facts, the decline in wetland surface, estimated at 50% since the 1900s in the Mediterranean region (MWO, 2012), continues today throughout the world. This surface decline leads to a loss, sometimes irreversible, of biodiversity and benefits for humans. Many national and international actions are being put in place to stop this loss, one of which is acquiring Ramsar status for the wetlands. The Ramsar Convention (1971, Iran) highlights Wetlands of International Importance according to nine criteria specific to the type of wetland, habitats, and animal populations inventoried on site (mainly waterbirds and fish). The status of a Wetland of International Importance is achieved if the proposed site meets at least one of the nine criteria defined by the Ramsar Convention.
Nevertheless, the lack of knowledge about the functionalities of wetlands and their physicochemical and ecological evolution over time makes them poorly understood ecosystems around the world. The data acquired in the field do not always make it possible to quantify the evolution of the wetland surfaces over time as well as their physicochemical parameters, nor to arrive at a complete inventory on a large scale. New technologies, such as remote sensing, are therefore involved in complementing knowledge and understanding the functioning of wetlands on a national or international scale.
Special remote sensing is a term that emerged in 1971 following the launch of the first satellite dedicated to the observation of terrestrial natural resources (Landsat-1). This discipline encompasses all the tools for acquiring, remotely, information on the Earth’s surface. The information is extracted from images of earth-orbiting satellites or aerial photos acquired from overflights by airplane. Remote sensing has the capacity to provide key information for wetland conservation, and thus many national and international projects have emerged in recent years.
Website of the Tour du Valat (https://tourduvalat.org/)
Website of the Ramsar network (https://www.ramsar.org/)