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Poster Session
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An application of Remote Sensing techniques in forestry Hazard Monitoring and Damage Estimation
- Meteorological Satellite Information Integrated with GIS to Increase Correct Interpretation and Precise Location of Forest Fires.
Due to the displacement under the Satellite, frequently large distortion is created in observation areas, which causes difficulties to observe and correctly locate forest fires. Although the application of Meter logical Satellite is to monitor and assess forest fires, location techniques are still very important.
In order to solve locating problem we have incorporated Geographic information system (GIS) into fire monitoring system by Meteorological Satellite data. Functions of GIS are: (a). Broadly locate and judge fire hazards areas, and provide timely information to the responsible organizations; (b) Set up geographic coordinates, identify fire occurrence site and provide basic data to fire fighting agencies; (c) mark out burned spots, increase the ratio of correct interpretation of fire sites, and to avoid misinterpretation problems that would indicate normal fire as fire hazard. Without such information, residential areas and brick kilns are mis-interpretated as fire hazards; and (d). Determine fire categories, and differentiate forest fire from wild fire in grassland.
By applying GIS, fire-locating accuracy by Meterological Satellite is incresed from 0.1 (latitude and longitude) to plus and minus 0.5 kilometer.
- recording Complete Course of Fire Occurrence and Spreading Servicing researches on Forest Fire
One of the important advantages of using Meterological Satellite to monitor forest fire is that it can record whole process from happening to expanding . It can trace back to the status before fire occurrence upon the request, which provide overall and actual information for forest fire research. For example, during the destructive forest fire in Daxinganling, we had collected all data of four passes eac day by Meterological Satellite from 1stof May to 30th of June of 1987. We conducted multiple researches and analysis by these data integrated with other information, such as decides the time of and research ofire occurrence with relation to the environmental factors, and found out the internal rule of suddenly occurred forest fire. Meterological Satellite data provide a clear evident on starting time of the destructive forest fire in Daxinganling because fire spots were found on the imagery which was caus\ght at tow o'clock in the afternoon on May 6th, and no spots were found on imagery that was caught back to May 1st; so the fire occurring time was determined without error, which facilitate the extraction of other related data (meterological data) to analyze the courses. Researches on fire stretching pattern, spreading speed, expanding trends were conducted which laid a better foundation for further understanding of fire hazard.
Generally, application of Meterological Satellite data in forest fire monitoring has created a wide research area, and it is a potential and valuable work but it has to be further developed.
Assessment of forest disastrous losses by Remote Sensing data
Wide application of remote, sensing techniques has provided and effective means to assess in a timely fashion forest losses caused by natural disasters, and understand different kinds of disasters.
Remotely sensed data used in evaluating forest disasters losses are acquired from SPOT, TM and Meterological Satellite. The types of disasters we have evaluated are forest and wind damages.
- Assessment of Burned Acreage by Meterological Satellite Data
Using Meterological Satellite Data to assess burned acrease after forest fire is charattrized by high speed, low cost, but precession is low.
After a forest fire it is an urgent need to know the burned acreage for rehabilitation project in order to work out a proposal for rescue construction. Although the traditional assessing method, such as ground survey, can provide reliable data, it has high cost and slow in speed. Using Meterological Satellite data can provide such information immediately after fire occurrence. For example, the destructive forest fire in Daxinganling was completely suppressed on June 6th. By using Meterological Satellite data we estimated the burned acreage was 1.32 million hectares with a accuracy 96% of the precise statistics.
A simple method to use Meteorological Satellite to evaluated forest fire losses is to count pixals, which are multiplied by pixels areas. In large burned region, the statistical precision of disastrous estimation by this method is over 90% and high statistical bias may occur in small areas (under five square kilometers). A relatively precise method to calculate fire damage is to integrates Meterological Satellite data with GIS which locates fire boundaries and estimates the acreage.
No matter what method is adopted, attention must be paid to te estimating operation which should be conducted after reduction of abnormal heat effects. A primary point is to judge burned areas by changes of grey scale in imagery because the low spatial resolution of the Meterological Satellite can easily cause an over estimation of burned areas.
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