抄録
Tropical rainforests was the primary land source for oil palm plantations development in Riau Province (Ramdani and Hino 2013). Our hypothesis is that the expansion of the area devoted to oil palm plantations at the expense of primary and secondary tropical rainforests will increase the local surface temperature. In this study, we used remotely-sensed data to quantify land use changes from tropical rainforests to oil palm plantations (Figure 1), calculated the surface temperature from thermal infrared data supplied by band 6 of the Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+), examined the correlations of surface temperature to foliage cover, and conducted field work to verify the results obtained using the remotely-sensed data.
For this study, we used a new spectral index, principal polar spectral greenness (PPSG) that is potentially more sensitive than other indices to small changes in foliage cover at high cover levels. The outcome of satellite image processing is only 0.2 °C different from direct temperature measurement in the field. Our study indicated that less density of the closed-canopy composition of oil palm trees resulted in higher surface temperature.
