KEMAMPUAN SALURAN TERMAL CITRA LANDSAT 7 ETM+ DAN CITRA ASTER DALAM MEMETAKAN POLA SUHU PERMUKAAN DI KOTA DENPASAR DAN SEKITARNYA

Abstract

This research was carried out in some parts of Bali Province, including Denpasar city and the surrounding regencies. The purposes of this research are: 1) to determine the pattern of surface temperature in Denpasar city; 2) to determine the accuracy level of the thermal channels in the Landsat 7 ETM+ and ASTER images for mapping the pattern of surface temperature in Denpasar city; 3) as well as to determine the relationship between the surface temperatures with building and with vegetation coverages. The method applied in this research are density slicing analysis, the 3rd ordo polynomial regression analysis, the root mean square different (rmsD), and the product moment correlations. The image enhancement techniques which are used in this research include thermal data calibrations, urban index transformation, and vegetation index transformation. The results of this study shows that the pattern of urban surface temperature spreads spatially and does not occur exclusively only in the city center but also in its surrounding areas; found in settlements with the density ranging from compact to more compact; also found in dry land with vegetation density ranging from sparse to sparser. Starting the value of rms difference can be used as the standard measurement in assesment of the surface temperature extraction accuracy. The 6.1st channel of Landsat 7 ETM+ image is the best which shows the rms difference of 4.95, followed by the 13rd channel of ASTER image with the rms difference of 5.73. The value of highly positive correlation between building density index with surface temperature is 0.73. It means that each increased of building density index value will be followed by increasing of surface temperature value. The value of highly negative correlation also happened between vegetation density index (vegetation coverage) with the surface temperature is -0.53. It means that each increased of vegetation index value will be followed by decreasing of surface temperature value.