Wetlands are the transitional lands between terrestrial and aquatic systems where the water table is usually at or near the land surface or the land is covered by shallow water. Wetlands play a significant role in maintaining environmental stability in a world where environmental degradation is increasing day by day. More than half of the wetlands in the world have been lost in the last century mainly due to human activities, including wetland draining or filling, hydrological alternations, chronic degradation due to nonpoint source pollution, and introduction of exotic species. Wetlands are the greatest natural resource recycling ecosystems with multiple nature services and develop a confluence of terrestrial and aquatic habitat to host rich biodiversity genetic resource and provide a critical refuge and breeding ground for many species. It plays a large role in water purification particularly in urban areas in regard to absorption of pollutants, toxins, heavy metals. Satellite remote sensing has proven to be a very useful technique for inventorying, mapping and monitoring of wetland ecosystems due to its synoptic coverage, multi-spectral character and repetitive nature.

Autorentext

Ratnadeep Ray,teaches Remote Sensing and GIS in the Department of Remote Sensing and GIS, Vidyasagar University and is involved in various kinds of research works in the same discipline.And Sakti Mandal,PhD Research Scholar in Department of Geography, University of Calcutta.Currently he has join as an Expert Member of Geography in WBBSE.