CHANGE DETECTION ANALYSIS WITH SPECIAL REFERENCE TO AQUACULTURE DEVELOPMENT IN WEST GODAVARI DELTA OF ANDHRA PRADESH, SOUTHERN INDIA USING GEOSPATIAL TECHNIQUES

摘要

Spatio-temporal studies on land use and land cover provide valuable information with regard to natural resources degradation and utilization. Geospatial techniques have widely been used in monitoring the land use and cover changes with special reference to aquaculture farming. The present study is aimed to assess the landscape changes occured in the delta region of West Godavari district, Andhra Pradesh state, South India using a series of multi-temporal satellite data over a period of two decades between 1996 and 2016. Changes were identified using Landsat-TM and OLI imageries and verified by field and other data. The change detection results were examined particulary in focusing the development and consequences of aquaculture within the study area. The accuracy of image classification has found to be more than 90%. The results showed that the agriculture land was enormously decreased to 213.2 sq km (year 2016) from 462.6 sq km in 1996 due to its rapid converstion into aquaponds. Established NDWI, MNDWI, NDMI, WRI indices were used to extract water cover from satellite data. MNDWI was found to be suitable for water feature extraction that produced better accuracy. The enormous growth of aquaculture led to the poor quality of soil and water, and crops deterioration in most of the regions of the study area. The study suggests that the integration of remote sensing and GIS was an effective approach for analyzing the land use and cover changes.