The Study, Based On Modis Data Fire Alarm

Forest eco-system plays an important role in the homeostasis of the entail nature. Our country is in short of forest resources but have many forest fires. Owing to the actual circumstance of the forest resources, improving the forest fire insurance will bring some reality meaning on the aspects of rising the forest overlay rate and protection of environment. The fire insurance includes two aspects: fire occurrence of earlier period forecast (always be called fire insurance grade forecast) and after a fire occurrence of earlier period detection (i.e. small fire point monitor).1. According to the earth's surface temperature of MODIS data anti- playThe temperature is the direct factor of the fire insurance forecast, By passing the influence to the environment, the high or low of the air temperature can indirectly act on the combustible thing, and change the physical property of it, then influence the fire insurance grade. Using the split-window arithmetic- According to the difference absorb of vapor between two close together channels, we take the earth's surface ratio radiation rate as input variables and then correct the atmosphere and earth's surface ratio radiation rate, so as to acquire the earth's surface temperature.2. According to the relative humidity of the MODIS data anti- playThe atmosphere moisture content is an important parameter of the forests' combustibility and measuring the spread speed of forest fire.The biggest influence of combustible thing is atmosphere moisture content, almost all forecast system have relationship with the input factor-atmosphere moisture content. The atmosphere moisture content and particular degree of humidity obtained by MODIS data can be used to calculate the relative humidity.3. Fire potential index application research analysisThe FPI model make use of the combustible thing model diagram, the burden of live and dead surface vegetation, degree of humidity to estimate the possibility of forest fire occurrence. Using the MODIS data take off all factors which fire forecast in used, including: relative humidity, temperature, 10 hours time lag combustible humidity, normal vegetation water index, vegetation green. The application of FPI molder factor in fire forecast was analyzed through the weather, vegetation data in Heilongjiang 2004-10 and other south provinces 2008-3, which were obtained by MODIS, will obtain Heilongjiang and south meteorology,4. The construct of FPI-△NDVI fire point monitor indexThe present research intends to introduce the author's fire-monitoring method of FPI-△NDVI, or a fire point index—FPI index by using the fire point radiation MODIS data and the 22 channels as well as the 31 channels (background radiation). According to the fire-monitoring principle and the difference between the background radiation and fire point radiation, fire accidents can take place usually only when the vegetation coverage reaches a certain extent. It is just for this reason that we have revised the conditions of the fire-occurrence and excluded the possibilities of fire-causing disasters by removing the areas with no vegetation and the places with scarce vegetation, for it is necessary to remove the liability for the bare soil or the urban thermal islands to get on fire.5. The application of FPI-△NDVI fire point monitor indexBy taking the fire that took place in Heilongjiang province on Oct. 15, 2004 and South as an example, in particular, this paper has drawn a few kinds of geographical features of the principle and analyzed the values of NDVI as well as the relations between the different surface types. Next, we have taken cloud as the biggest factor that helps to define FPI and the NDVI threshold value with the vegetation being the key factor influencing the fire burning. Three strong points can be found in the use of MODIS absolute fire point recognition algorithm, which can be illustrated as follows: first of all, it is the noise ingredient for the effective attenuation-detecting instrument; secondly, it may have some counter-balanced influence on the air movement in a certain degree; third, it helps the fire-detectors' to narrow their scanning attention. Thus, it can be concluded that the suggested method of ours helps to enhance its monitoring precision with greater extraction speed.