Summary: | 碩士 === 國立成功大學 === 環境工程學系碩博士班 === 101 === Indonesia's tropical rainforests are the third largest in the world. However it has been also reported that Indonesia is now the second deforestation in the world. While rapid deforestation is reported in Sumatra and Kalimantan during the last two decades, Papua is the last island which still has large proportion of forest cover among the major islands in Indonesia. Many deforestation studies focus on Sumatra and Kalimantan, but only few in Papua. However the deforestation studies need to be conducted for Papua to maintain the existing forest and to analyze the possibility of deforestation in Papua. Because more logging concessions have been granted for timber and industrial development since 2000, deforestation rates are expected to be increased. However, no data for the spatial and temporal distribution of deforestation particularly for the year after 2000 exist. This study aims to evaluate the status of forest and the effectiveness of policies applied in Papua. Two major challenges in this study were i) to understand “forest change” beyond make understanding of “total forest cover lost”; ii) to obtain/acquire a consistent remotely sensed data overcoming limitations imposed by the large amounts of cloud cover in Papua every year. Moderate Resolution Imaging Spectroradiometer (MODIS) land cover data used a consistent land cover classification system throughout the world in the annual time series from 2001 to 2007. It allows getting a better understanding about the characteristic of spatial and temporal of deforestation in the large area with annually data availability overcoming the two challenges above mentioned. Together with GIS change detection methods with a classification approach is used to track deforestation in Papua Island. The MODIS landcover data was reclassified to two classes (forest and non-forest). We develop a change detection algorithm to detect the deforestation and reforestation area by identifying the difference between multi-year reclassified landcover data. A significant part of overlapping between the detected deforestation and reforestation area was found, because the 500m resolution landcover data is insufficient to identify the type of change when reforestation and deforestation were both occurred in a small region (such as a permitted unit or area). Since there is no information available to identify the overlapping, we assume that the overlapping area was contributed by deforestation and reforestation evenly. Based on this assumption of overlapping, our change detection result showed that the 7-year deforestation and reforestation area in Papua was 617,613 ha and 1,466,988 ha, respectively. Based on regency specific of deforested area, Merauke contributed 46% of deforestation in Papua Island. Jayawijaya become the most deforested regency where 24% of its area is deforested. The largest deforestation (296,094 ha) happened in the south part of Papua which is the area of agricultural expansion and followed by the middle part of Papua about 122,021 ha where mining and agriculture exist. The deforestation rate in Papua was estimated to be 102,936 ha/year by linear regression. A considerable area of deforestation was detected in the first changing-period (2001-2002) because many new concessions were granted for industrial development. The rate derived in this study is 30% and 37% lower than the rate estimated in 1950-1985 and 1985-1997, respectively. The number of reforestation showed 58% higher than deforestation number (42%), it indicated that forest management start run well. However, considering Papua is the last region which still has a large proportion of forest. Government should pay attention of those deforestation activities, control the granting of concession permits and enforce the law to mitigate deforestation in Papua.
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