Remote Sensing of Coastal Ecosystem

Ecosystem is a unit of ecological community, comprised of biological, physical, and chemical components. The coastal ecosystem is the region of highly dynamic, diverse and productive region on the earth due to the combined action of physical features and bio-chemical processes from land and ocean. Coastal habitats perform a variety of important functions within the ecosystem and support the life history and ecology of many species. The shallow estuarine and nearshore habitats (e.g., submerged aquatic vegetation and large woody debris) are structurally complex and dynamic. They are the nursery areas for juveniles and provide food, refuge from predators, spawning habitats, and a transition zone to physiologically adapt to salt water existence. The sediment and morphodynamics of the nearshore region provide basis for foodweb based upon the nutrient supply and detritus produced by plants like marine algae, estuarine and saltmarsh vascular plants, and eelgrass that grow in highly productive shallow water habitats. Nearshore ecosystem plays a critical role in support of a wide variety of biological resources, many of which are commercially, culturally, aesthetically, and recreationally important to the people of the region. Coastal wetlands act as a buffer to major storm impacts, particularly to damaging storm surges associated with cyclones. Coastal sand areas are an important source of fine aggregate material and beaches are recreational enjoyment, act as breeding, rest and feeding areas for fish, wildlife and waterfowl, and serve as buffer zones in shoreline protection. Recent studies estimate the global economic value of all the services costal wetlands provide to be in excess of $1.6 trillion per year. Coastal wetlands such as brackish water lakes, tidal marshes and mangrove forests, occur at the boundaries of land and ocean and because of their unique position in the landscape, they provide many important ecological services that maintain and improve the health of our earth’s environment. Tidal marshes and mangroves store flood waters that run off from upland, thereby improving water quality by filtering out sediments and nutrients. They are critical habitat for juvenile and adult stages of many economically important marine fish and shellfish species that spend part of their life in the oceans. They also provide essential habitat for many species of waterfowl and wildlife. Study of different biological resources and associated geological processes of the coastal zone enhance the understanding of linkage between biotic and non biotic components and their mutual dependence in sustaining the ecosystems integrities. Different Sensors onboard the remote sensing satellites in orbit have provided greater scope in mapping, monitoring and modeling global, regional and local phenomenon like El Nino, global warming, drought, sea level change, cyclone, fronts and gyres, and flood; processes like erosion and sedimentation,