The Research On Evaluation The Method Of Forest-fire Extinguish In Guangzhou

Guangzhou experienced from cut trees for timber production to plant trees in ten years, nowadays it transit to the ecology city, establishing the forest urban. Forest as the most important part of Guangzhou, forest fire often takes place. But how to constrain the loss of the forest-fire, it urgent needs to select the more effective method of fire-fighting, minimum the loss of forest-fire, protects the security of urban ecology.Before 2006, Guangzhou traditional forest fire-fighting method is use wind-force extinguisher, chain saw, chopper open firebreak, No.2 tool and portable squirt to put out the fire. Although the firefighters have some water pumps at that time, it used in few time, more than 90% of the fires are still use the traditional method. In 2006, the fire-fighting method has covert to water-base fire-fighting. It widely use the high-pressure water pump,fire-fighting vehicle and other coorperate technology. Trainning large quantities of professional fire-fighters, The traditional method only use in clear up fire weak area or even not use.This dissertation Reviews the domestic and international forest fire fighting methods and the evaluation of the fire-fighting method. The guideline is systematic science, economics, forest fire science, fire ecology and forest fire managemen, Investigation and study of the socio-economic, geographical, forest resources and forest fire prevention status in Guangzhou City. To meet the Guangzhou City into a "forest siege, the city in the forest," the sustainable development of the metropolitan landscape ecological forest fire prevention work on the needs of the application of qualitative and quantitative analysis method, select 2005 and 2006 as an evaluation time scale. using the effects of fighting to evaluate two fire-fighting methods in Guangzhou.Through the qualitative analysis in two methods, Compare water-based fire-fighting methods with the tradictional methods the main advantage of the water-based fire-fighting methods is as follows:①less firefighter take part in and high safety②Put out more fast, high efficiency③Low probability to back fire④forest survival rate is high, ecological restoration fast⑤Low budget, benefit-cost ratio higher. And discuss each.And then use the comprehensive evaluation method to quantitative evaluate two fire-fighting methods. The results are as follow:(1)Through collecting the dates of the 2 kinds of method, choosing 6 relevant evaluate indexes as follow:the burnt area of the forest fire, injured forest area, amount of direct and indirect economic loss, amount of ecological value loss, set up the forest fire extinguish method evaluation index system, provide each kind of concrete index compute method.(2)Through collecting the forest fire dates of Guangzhou, I find the 20% fires take more than 80% amount of fire burnt area annually. So I arrange the dates from large to small, and choose the dates larger than 80% fire of total burnt area for evaluation, after calculate, there are both 24 fires conform to the condition in 2005 and 2006. then categorize the rank of each fire according to Forest Fire Prevention Regulations, Results shows that there are 6 great forest fires in 2005, and the greatest fire burnt area is more than 200hm2, the rest 18 fires are the ordinary fire, there is only ordinary fire in 2006, and the greatest fire does not exceed 17hm2. Compare 2005 with 2006, the ratio of burnt area is 8:1.(3)Use AHP method to get the weights of each index. Obtain the judging matrix through expert's investigation method, then can calculate out the weight of each index. The result shows:The burnt area of forest fire is 0.238, injured area is 0.252, direct economic loss is 0.126, indirect economic loss is 0.214, ecological value loss is 0.170.(4) The dates after standardized combine with the weights calculate annual forest fire loss composite index:The extremely difference standardize method was used in standardization. Use the standard.dates to calculate the forest fire loss composite index.According to result, the forest fire loss composite index is 8.9 in 2005, and 0.7 in 2006. Compare 2005 with 2006, the ratio of composite index is 12.5:1.(5)Compare with the ratio of burnt area in 2005 and 2006, the ratio is grow from 8:1 to 12.5:1 when use the composite index evaluation, and the proportion is expanded as 12.5:1 according to composite index, the reason to cause disparity is as follows:①Evaluation with single index can not consider every aspect in forest fire influences, but the composite index evaluation assessment can think about more deeper.②water-base fire-fighting method can lower the temperature, reduce the high-temperature impact on trees, and increase the rate of survival, decline the forest losses in burnt area.③The method of isolate combustible things from the edge of fire line will divide the continuous forest zone into separate, in addition, the rate of survival in the inner burnt area is low, cause the reciprocation decrease, and the ecology in this area is hard to rebuild; On the contrary, firefighting with water does not separate the continuous forest zone, and the water can help the plant recover, so the loss of ecology will minish in long term.