Monitoring farmland loss and projecting the future land use of an urbanized watershed in Yogyakarta, Indonesia

摘要

This study analyzes land use changes in Yogyakarta, Indonesia, specifically farmland loss, which has occurred as a result of rapid urbanization by employing remote sensing, GIS, and land use modeling techniques. Landsat images from 1992 and 2004 and ASTER Terralook images from 2009 were classified using a supervised classification to generate land use maps. Land use change was detected using a post-classification method. During 1992-2009, high-density built-up areas increased by a factor of 3.7, and 80.47 km~2 of farmland was lost due to land conversion to built-up areas during the same period. Based on these findings, land uses for the year 2029 were spatially simulated using Dyna-CLUE model for three scenarios: business as usual, farmland protection, and minimum required farmland. The results reveal that the ongoing trend of land use conversion combined with the lack of implementation of proper spatial policies will lead to a large loss of farmland and that it is desirable to protect prime farmland from urban sprawl.