Florian Siegert, Gernot Rücker^* & Anja Hoffmann^**

ABSTRACT - In spring 1998 fires have devastated large areas of tropical rainforests in Kalimantan Timur on the island of Borneo in Indonesia. Here we report on results of the synergistic use of NOAA-AVHRR and multitemporal ERS-2 SAR data to analyze this disaster. Using a temporal sequence of more than 150 NOAA-AVHRR hotspot data sets acquired from January to April 1998 and a multitemporal series of 6 ERS-2 scenes we were able to quantify the extent and impacts of the fires and trace the origins of some fires. Virtually all primary (lowland and swamp) forests of the Mahakam basin have been destroyed: The total area severely affected by fire in Kalimantan Timur alone is estimated to be about 4 mil. ha, an area as large as Switzerland. In this study we combined information from the high temporal resolution of the NOAA-AVHRR system and the high spatial resolution of the ERS-2 SAR to derive precise figures on the extent of the fire damage and to gain insight in the spatio-temporal dynamics of the fires. The project was conducted on behalf of the Integrated Forest Fire Management project (IFFM) based in Samarinda, East-Kalimantan,Indonesia. IFFM is a Indonesian-German co-operation project and provides information on fire risk and fire occurrences in East-Kalimantan and receives images from NOAA AVHRR 12, 14 and 15.