Application of Geospatial Technology for Wetlands’ Mapping and Change-Detection: A Case Study in Selected Areas of South Eastern Coast in Ampara District, Sri Lanka

In global context, the anthropogenic pressure increases the loss of wetland and its resources. Wetlands and estuaries are highly productive and act as critical habitats for a variety of plants, fish, shellfish, and other wildlife (Klemas, 2011). The detection and evaluation of the wetland with modern technology is an important phenomenon to conserve the wetland area and its ecosystem. Remote sensing (RS) has a long history of successful applications within the field of wetland delineation, using a multitude of satellite platforms and sensors (Allan, 2016). This paper is an attempt to object-based approach to derive the change detection inventory information of wetland for selected administrative areas of South Eastern coast in Ampara District within the period of 1991 to 2017 using Toposheets and Google Earth imagery. Further, it also explores the human activities which pressure on wetland including agricultural practices (land encroachment), new settlements, solid waste dumping, land cover changes and etc. Google Earth imagery of 1991 and 2017 were collected and subjected to the GIS analysis to find the result of this study. According to the results, agricultural and built-up area has increased in 1991 by (9.4 per cent), 2017 (16.4 per cent) and 1991 (0.1 per cent), 2017 (2.1 per cent) respectively whereas there has been a decrease in the forest and wetland areas in the years of 1991 (80.3 per cent), 2017 (72.7 per cent) and 1991 (3.5 per cent), 2017 (2.9 per cent) respectively.