ESTIMATION OF CARBON STOCK CHANGES IN ABOVE GROUND WOODY BIOMASS DUE TO VOLCANO PYROCLASTIC FLOW AND PYROCLASTIC SURGE THE CASE OF MERAPI VOLCANO NATIONAL PARK

SELLI FIDI YANI WARDANI, Prof. Dr.rer.nat. Junun Sartohadi, M.Sc.

2013 | Tesis | S2 Geo-Informasi untuk Manajemen Bencana

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Merapi volcano is active volcano which is well known for its pyroclastic flow. Merapi Volcano National Park (MVNP) is susceptible to volcanic hazard since it is located around Merapi volcano. Carbon sequestration in the national park is becoming a priority of forest development as stipulated in Government Regulation Number 28 Year 2011 and Number 49 Year 2011. Therefore, this study aims to know the effect of pyroclastic event to carbon stock in MVNP. In this study the natural carbon rate recovery in MVNP was estimated to determine the growth rate of natural carbon recovery in MVNP. Carbon stock in rehabilitation area was also estimated since there is rehabilitation activity in MVNP. To estimate carbon stock change in MVNP, 2006 QuickBird and 2011 GeoEye satellite imageries were used. Object based image segmentation of high resolution satellites imagery could recognize physical dimensions of individual trees such as crown projection area (CPA). In this study, carbon stock was derived using allometric equation based on measured diameter at breast height (DBH) in the field. A model was developed to estimate carbon stock based on DBH estimation in the field and segmented CPA from the image. Earlier studies had shown that a relation exists between CPA and DBH. Carbon in affected area was estimated based on field measurement because no tree crowns were visible here. Based on the segmentation process, the model of CPA and Carbon in MVNP was developed. The F score which indicate the accuracy of segmentation of needle leaf and broadleaved of 2011 GeoEye were 0.68 and 0.54 respectively. Logarithmic model which has 6.37 % error was used to estimate broadleaved carbon stock while quadratic model which has 10.31 % error was used to estimate Pine tree carbon stock in MVNP. Merapi volcano erupts 4-6 years periodically since 19th century with Volcanic Explosivity Index (VEI) ≤ 2. The VEI 2 pyroclastic flow could reach distance to 7 km from the crater with different direction. Since MVNP is located in range of 7 km from the crater, it always prone to pyroclastic flow. In the affected area, carbon stock is high in the area farthest from the crater.

Kata Kunci : Merapi Volcano National Park, carbon stock, crown projection area