Land Use and Land Cover Change Detection using Remote Sensing and Geographic Information System in Bodri Watershed, Central Java, Indonesia <Research Note>

Remote sensing and GIS technologies are very useful for mapping LULC patterns and detailing the dynamics of a certain area. The utilization of these technologies has been applied to Bodri watershed in Central Java, Indonesia. The aims of this study are to map and detect LULC changes in Bodri watershed over the last two decades (1991-2001 and 2001-2009). Three data sets of Landsat image acquired on June 28, 1991; July 1, 2001 and June 21, 2009 were used for this analysis. Image classification for mapping LULC was performed by supervised classification through the maximum likelihood method. All of the visible and infrared bands (bands 1-5 and 7) were used for the analysis. LULC change processes were then detected through post classification comparison method. Analyzing LULC changes associated to its slope and elevation were performed by overlaying the classified image with slope and elevation maps which had been extracted from digital topographic map (1:25,000). Six LULC categories were classified as forest, tree plantation, dry farming field, paddy field, settlement and water. The results show that in the period of 1991-2001 there were increases in settlement (56.22%), dry farming field (41.77%) and water (32.41%), and decrease in forest (-31.85%), tree plantation (-15.19%) and paddy field (-12.23%). While, between 2001 and 2009 increase occurred in water (34.17%), tree plantation (12.63%) and settlement (7.47%), and decrease in paddy field (-26.01%), forest (-12.33%) and dry farming field (-1.14%). The changes predominantly took place in the gentle slope (0-8%) and the low elevation (0-500 m) areas. These results show that urbanization and agricultural activities have occurred in these areas. The low land and gentle slope were more widely affected by and vulnerable to human and agriculture caused LULC changes than highland and steep slope areas.