The Research Of Forest Health Risk In Guangzhou

At present, forests are facing many severe unhealthy risk issues in China, such as low forest coverage, poor site quality, simple stand structure, increased plantations, reduced biodiversity, severe soil erosion, forest disasters etc, each year they produced enormous ecological and economic losses to our forests. Therefore, comprehensively understanding, objectively analyzing, scientifically making a strategic decision of forest health risks is an important task for sustainable forest management from the system and overall perspective, has important theoretical and practical significance to promote the sustainable development of forestry.The research of this paper is an important part of a major project "Guangzhou Digital forestry and trees of wood protection system construction projects"(GZIT2010-ZB0533) which charged by my mentor as the total technical director. This paper takes the system science theory, sustainable development theory, forest health theory, and so on, as a guide, conduct comprehensive study of forest health risks in Guangzhou. During the course of the study, the research progress at home and abroad on the connotation of forest health, forest health risk factors, risk assessment of forest health, forest health risk warning are reviewed, and we make an evaluation, early warning, prevention research on forest health risks from three aspects of forest structure, function, environment, combining the physical geography, socio-economic, forest resources and forest health status quo of Guangzhou. The main findings are as follows:(1) combining with the latest research results of domestic standards, experts and scholars, select20categories of risk factors from the three aspects of forest structural, functional, environmental risks, conduct in-depth analysis and calculation for forest health risks of Guangzhou and its eight regions (municipalities), and divide into15categories of factors (C class) according to function categories.(2) In the15categories of (C class) forest health risk factors, there are a number of indexes (D class) in each category, in accordance with the principle of index selection, combining with qualitative analysis, make measure analysis and screen out 22evaluation indexes of forest health risks, work out a classification threshold table of the22evaluation indexes of forest health risks, build evaluation index system of forest health risks.(3) By means of Standard Ratio Method and Efficacy Coefficient Method, two groups of22level values of evaluation indexes of forest health risks have been gained in Guangzhou and its eight regions (municipalities), and provide a quantitative basis for forest health risks assessment and its analog evaluation.(4) The weights of22evaluation indexes of forest health risks have been obtained with the help of Analytic Hierarchy Process (AHP) in Guangzhou, respectively D1(0.006), D2(0.018), D3(0.009), D4(0.009),D5(0.010), D6(0.010), D7(0.043), D8(0.045), D9(0.015), D10(0.015), D11(0.015), DI2(0.046), D13(0.046), D14(0.046), D15(0.031), D16(0.043), D17(0.192), D18(0.192), D19(0.069), D20(0.113), D21(0.013), D22(0.013).(5) Select four methods of composite index method, efficacy coefficient method, artificial neural network method, and fuzzy comprehensive evaluation method, take the year as time scale, take Guangzhou and its eight regions (municipalities) as spatial scale, and construct risk evaluation models. Through the models, this paper calculate four groups of risk evaluation index value, and conduct analogy evaluation of forest health risks. Comprehensive evaluation level of forest health risks has been considered as slight according to the five risk rank criterion.(6) Based on the early warning indexes screening principle, through qualitative and quantitative analysis, screen out the16risk early warning indexes; determine the limits of the various risk early warning indexes including the five risk early warning rank of non, mild, medium, high, huge. Finally establish early warning indexes system of forest health risks.(7) Get the weights of the16early warning indexes including the forest no-coverage rate, the plantation area occupancy, commercial forest area occupancy, forest growing stock per hectare on average by applying analytic hierarchy process mothod:0.018,0.0180,0.018,0.018,0.033,0.033,0.057,0.057,0.064,0.064,0.027,0.027,0.167,0.167,0.065,0.167. (8) Determine the early warning index values of Guangzhou and its eight districts (municipalities) by applying efficacy coefficient method and the standard ratio method. Conduct the single index police intelligence forecast as for the16early warning indexes, establish corresponding early warning model by using Composite Index Method and Efficacy Coefficient Method, acquire two groups of the early warning composite index values of forest health risk of Guangzhou and its eight districts(municipalities):respectively0.271,0.283,0.277,0.258,0.316,0.262,0.263,0.239,0.324and0.659,0.682,0.614,0.637,0.542,0.643,0.681,0.682,0.619. The early warning status of forest health risks of Guangzhou and its eight districts(municipalities) is light and the early warning level is two according to the early warning level criterion.(9) Through the study of all types of forests disaster laws, regulations, and number of files during1984-2011years, analyze the problems which exist in forest fires, pests and diseases, meteorological disaster prevention and the issues which exist in the operating right and transfer process of woodland, propose to establish a sound legal system of Guangzhou forest health risks; build forest health risks catastrophic insurance communities; establish forest health risks dynamic early warning system; improve the prevention techniques and measures of forest health risks to guard against future forest health risks.Forest health risk is dynamic, random, there are many types of risk, the influencing factors are complex. the forecasting and early warning, prevention, governance of forest health risks will be a long and arduous task, the research on forest health risks is a complex system project. With the development of science and technology, new theories, new methods, new technologies will be further applied to the study of the forecasting and early warning, prevention, governance of forest health risks, carrying out a comprehensive study on forest health risks has a very important significance. to reduce the ecological and economic losses and promote sustainable development of forestry.