FOREST DEGRADATION ASSESSMENT IN KALIMANTAN TROPICAL RAIN FOREST (KTRF) USING PHENOLOGICAL AND GEOMETRICAL SHAPE ANALYSIS - Darmawan, Mulyanto (GEOMATIKA, 2010)
Kalimantan tropical rain forest (KTRF), for many years, has been subject for timber extraction, agriculture and plantation expansion, as well as settlement. Although it has experiencing ever land clearing, forest degradation both in spatial and temporal are poorly studied. Many researchersâ works in the forest field had considered that forest degradation is similar to deforestation. They defined a simple definition of deforestation as âconversion of forestâ. When such definition applied, it would create large area of forest degradation. In this study phenological analysis were applied to scale up the understanding of forest degradation in KTRF. In the initial stage, phenological analysis was evaluated using NDVI SPOT Vegetation 10 days composite. Secondly, K-mean classification and Knowledge Base Expert System (KBSE) method were applied to nine phenological metrics (Onset, End, Max, Min, AMP, RtUp, RtDn, and DUR, TIN) to calculate proportion of forest (Pof) and connectivity of forest with other non forest (Cof). Finally, the Geometrical shapes of forest were evaluated to understand forest degradation in Kalimantan forest. Result found that about 46% of Kalimantan forest has been threatened or experience with forest clearance which correspond to plantation and agriculture crops for 26,76% and of 19,24% was patch forest. While the other of 53% was represent natural forest. Of the 53% of the natural forest actually 55% was corresponding to transitional forest, perforated and edge forest at about 8%, 9% and 37% respectively. The critical point found in the phenological analysis mainly to determine the starting point of growing season (Onset) and the end of greenness (End).Keyword: tropical rain forest, deforestation, degradation, phenology analysis, geometrical shapeABSTRAKHutan hujan tropis Kalimantan (KTRF), selama bertahun-tahun, menjadi sumber pengambilan kayu, perluasan pertanian dan perkebunan, termasuk permukiman. Meskipun hutan ini mempunyai sejarah panjang pembukaan lahan (land clearing), informasi tentang degradasi hutan baik secara spasial maupun dan multi waktu sulit didapat. Banyak peneliti di sektor kehutanan menyederhanakan bahwa âdegradasi hutanâ adalah âdeforestasi hutanâ. Mereka menetapkan definisi sederhana deforestasi sebagai "konversi hutan". Namun, ketika definisi tersebut diterapkan, akan menghasilkan luasan angka degradasi hutan yang besar. Dalam studi ini phenological analisis dilakukan untuk meningkatkan pemahaman (Scale up) informasi degradasi hutan di KTRF. Pada tahap awal, phenology dievaluasi dengan menggunakan NDVI SPOT Vegetasi 10 hari komposit. Tahap kedua, klasifikasi K-mean dan method Knowledge Base Expert System (KBSE). diterapkan atas sembilan metrik phenologi (Onset, End, MAX,MIN, AMP, End, RtUp, RtDn, dan Dur, TIN) untuk menghitung proporsi hutan (POF) dan konektivitas hutan (COF) dengan hutan non lain (COF). Akhirnya, bentukan geometris (geometris shape of forest) dievaluasi untuk memahami degradasi hutan Kalimantan. Hasil sementara adalah sekitar 46% dari total hutan Kalimantan terancam ataupun mengalami perubahan, akibat adanya pembukaan hutan baik untuk perkebunan atauypun tanaman pertanian masing-masing sebesar 26,76% dan 19,24% diantaranya adalah hutan patch. Sementara hanya 53% wilayah Kalimantan masih merupakan hutan alami (natural forest). Dari 53% dari hutan alami sebenarnya hanya 55%, sementara hutan transisi (transitional forest), hutan perforasi (perforated forest) dan hutan tepi (edge forest) masing-masing sekitar 8%, 9% dan 37% dari ttal forest. Pekerjaan tersulit yang ditemukan dalam analisis phenological ini adalah pada penentukan titik awal musim tanam (Onset) dan akhir kehijauan (O). Setelah kedua metrik tersebut ditentukan, maka metrik yang lain dapat dihitung.Kata Kunci: Hutan hujan tropis, deforestasi, degradasi, phenologi analisis, bentukan geometrik