Metode Neraca Energi Untuk Perhitungan Radiasi Transmisi Menggunakan Data Citra Landsat ETM+

Abstract

Radiation transmission is needed for forest vegetation especially for the ecosystem under canopies. Quantity of radiation which could reach into the surface of forest influences chemical, physical, and physiological processes of plants like photosynthesis, transpiration, and respiration. The object of this study is analyzing factors that effect magnitude of radiation transmission in some land covers using Landsat ETM+ images and mapping distribution of radiation transmission. The image was classified into three land covers of vegetation. Those are natural forest, planted forest and shrub. Information of surface temperature was extracted from band 6 (wavelength : 10.40-12.50μm); component of surface energy was extracted from band 1 (0.45-0.52 μm), band 2 (0.52-0.60 μm), and band 3 (0.63-0.69 μm); and calculated absorbtion and reflection of radiation to estimate radiation transmission. Radiation transmission of natural forest in 2000 is 257 Wm-2, planted forest is 247 Wm-2, and shrubs is 231 Wm-2. While in 2001, radiation transmission of natural forest is 129 Wm-2, planted forest is 112 Wm-2, and shrubs is 104 Wm-2. Radiation transmission in 2000 was higher than in 2001 because of differences of zenith angle and distance of the sun to the earth in both of satellite data that used.