MONITORING TEMPORAL VARIATION IN AQUAPONDS USAGE AND MAPPING SPATIAL DISTRIBUTION OF ABANDONED AQUAPONDS IN COASTAL REGION OF ANDHRA PRADESH USING GEOSPATIAL TOOLSPrasuna Rani P., Sunil Kumar M. and Geetha Sireesha P.V.Abstract Coastal ecosystem is highly fragile and considering the impact of climate change, it is necessary to monitor the resources periodically using technologies like remote sensing and GIS. A study was carried out to monitor the temporal and spatial variation in aquapond usage and the extent of abandoned ponds in erstwhile Guntur district, Andhra Pradesh. The satellite data based digital interpretation techniques and optical indices were considered for the study. The satellite data pertaining to 2017, 2018 and 2019 were processed and analyzed for land use and land cover with decision rule classifier algorithm using spectral indices individually and in combination (considering indices like NDWI, NDVI, MNDWI and WRI) with the help of thresholds. The aqua pond region left unutilized continuously for three years were considered as abandoned ponds. Results indicated that there was a variation of around 1000 ha in extent as well as spatial distribution of used ponds in different seasons. The maximum extent of used aquaponds was observed during February-May season in 2018, while the lowest extent was observed during August-December period in 2017. Overlay analysis of both the seasons in a year indicated that a maximum of 4303 ha of aqua pond area was left empty or unused throughout during 2018. Overall, an extent of 1324 ha of land was found to be left unutilized during all the years of study, i.e 2017, 2018 and 2019 and is considered as the abandoned aquapond area. The highest abandoned aquaponds region was observed in Nizampatnam mandal. |