Meteorological Conditions in South East Asia
8 December 1998
The ASEAN Fire Weather Information System (ASFWIS) a co-operation between ASEAN and the Canadian Forest Service it provides maps describing the current fire weather situation in South East Asia. This system is based upon the Canadian Forest Fire Danger Rating System (CFFDRS) (for further infomation to the CFFDRS refer to http://www.nofc.forestry.ca/fire/asean), and is currently tested on an experimental basis. Studies have shown that the CFFDRS is applicable outside of Canada. Currently it is also used in a modified form in New Zealand (see References). In New Zealand the Fire Weather Indices Fine Fuel Moisture Code (FFMC) and the Initial Spread Index (ISI) represent the fire danger in the scrublands. The Duff Moisture Code (DMC) is also applicable in South East Asia, because it potentially describes the moisture state of the upper peat layers in peat and peat swamp forests. All three parameters may serve as a suitable indicator of forest fire danger in South East Asia.
According to the ASFWIS (http://www.nofc.forestry.ca/fire/asean/) for 24 November 1998 these parameters are slightly increasing almost all over South East Asia. The highest FFMC readings are recorded for northern Vietnam, with the FFMC ranging between 90-92. Due to changed weather conditions, the ISI readings in northern Thailand and northern Vietnam decreased over the last days.
Fig.1. FFMC output of the ASFWIS
Fig.2. DMC output of the ASFWIS
Fig.3. ISI output of the ASFWIS
These findings are consistent with the current weather reports from Badan Meteorologi dan Geofisika (http://bmg.cbn.net.id/) which records rainy and cloudy conditions for Indonesia with temperatures between 18°C (Bandung) and 32°C (Samarinda) with relative humidity ranging from 60% up to 98%. The general forecast for whole Indonesia is rainy and cloudy.
The Meteorological Service of Singapore (http://www.gov.sg/metsin/hazed.html) reports on 7 Dezember 1998 for the South East Asian region "cloudy conditions were again observed over central Sumatera. No hot spots were detected". The Meteorological Service states for the near future that: "rainfall in the region is expected to be near or above normal for the next few months. However it should be noted that many parts of Indonesia (Kalimantan and parts of Sumatera) would be in their traditional dry season in the next few months. As such, though extensive and prolonged smoke haze is unlikely for this period, occasional short periods (e.g. a few days) of slight to moderate haze in a more localised manner remain probable".
The FFPCP project in Palembang (http://www.mdp.co.id/ffpcp/overview.htm) records no hotspots on 5,6 and 7 Dezember 1998.
Summary: Although the current fire weather conditions do under normal conditions not favour extensive land clearing by fire or escaping wildfires, the consequences of the large wildfires of 1997-98 must been taken into consideration. These fires had caused extensive degradation of primary and secondary forests along with the spreading of "alang-alang" (Imperata cylindrica) grasslands. These grasslands facilitate the spread of uncontrolled fires over large areas. It can be predicted that in November-December with only moderate fire danger new vegetation fires will occur.
See also the IFFN Country Notes.
