Spaceborne radar monitoring of forest fires and forest cover change : a case study in Kalimantan (2007)

The devastation of tropical rain forests has been proven to have a significant effect on global climate change. The sustainability of these forests becomes a major concern for the international community. The Indonesian Ministry of Forestry (MOF) is eager to carry on forest inventory activities and to generate forest resources information.Advanced spaceborne radar techniques are a very promising tool to monitor forests. This technique is complementary with the existing spaceborne optical imagery which suffers too much from cloud cover. Radar provide reliable information on a regular basis and has been applied in various types of applications e.g. forest classification.The approach presented in this thesis includes. Firstly, multi-temporal classification of spaceborne Synthetic Aperture Radar (SAR) data using Iterated Conditional Modes which is proposed as a fast step of Maximum Likelihood classification in order to circumvent the slow image segmentation step. Secondly, slope correction dealing with steep slopes that considerable has geometric distortion. Thirdly, textural analysis has been applied to derive additional information layers in multi-temporal classification from fine structures in the radar images.The study focuses on three test site areas i.e. Sungai Wain test site area, the Gunung Meratustest site area and the NASA AirSAR PacRim-II test site area.This area experienced long drought periods associated with the El Niño Southern Oscillation (ENSO)phenomenon. For this study the severe ENSO event of 1997 - 1998 is of particular interest.Forestfires occur almost every year in this test site area, however,each event is specific in intensity and extent. A longer time series ofradar images takes every event observations into account.The results show high accuracy ranging from 85.2% to 98.8% for almost all land cover types. Slope correction has positive effect, but in accuracy does not seem to be very high. It is showed that the induced slope correction is around 1 dB while values up to 10 dB were expected. The resolution of the digital elevation model is an important factor for the correction of relief in spaceborne SAR data. When the resolution is too coarse, i.e. spatial features of slope correction are coarser than the actual structures; the pattern of relief will be flattened out. Utilization of textural features yields a significant improvement of overall classification accuracy, which increases from 36.5% to 48.5%.The approach developed for the Gunung Meratus has a wide applicability. This approach seemed to be sufficiently mature to apply it for others areas, for example the Mawas and Sebangau peat swamp forest area. This methodology of radar monitoring system may have the potential to become the core system for 'fast illegal logging response' within the Indonesian MOF.The implementation of the SAR monitoring for the Indonesian MOF is speeding up the ongoing decentralization policy. Recommendations are offered here to the Indonesian MOF, particularly for local authorities to enhance their capability in providing fast, accurate, and reliable information on forest condition. This capability will ensure the sustainability of the remaining tropical rain forest in the country.