Research On Forecasting And Early Warning Of Outbreak Risk Of Sudden Oak Death

“Tree flue” is a devastating disease for the trees and plants,which is caused by a special germ.This disease is known as the sudden oak death in America.The trunk of a plant infected with the germ will shed black liquid,and the leaves will wither immediately,which will cause the plant to become black from the root to leaves,and to die eventually.At the same time,the foliage of infected host plants can produce sporangia and spread long distances with wind or rain.At present,Sudden Oak Death mainly occurred in the west coast of the United States,Britain,France,Germany and so on.However,with the progress of globalization,the possibility of Sudden Oak Death spreading to other suitable areas is continuously increasing.In its fifth assessment report,the UN Intergovernmental Panel on Climate Change(IPCC)pointed out that there were four possible trends in future climate change based on the different GHG emission patterns.With the change of climate,the global change of the risk of Sudden Oak Death outbreak should be studied.This study is a part of remote sensing diagnosis of forest ecological health in environmental health remote sensing diagnosis system.Based on the latest Sudden Oak Death outbreak data,global land cover data and meteorological data from 2000-2017,the paper uses Maxent model to predict the risk areas of Sudden Oak Death in different climate scenarios and different periods.The predicted results of China,the west coast of the United States,and Europe were contrasted and analyzed.Hysplit model was used to conduct early warning research on the Sudden Oak Death propagation trajectory in Zhangzhou,Fujian Province,China and California.The main research contents include:(1)To collect SOD outbreak data and various climatic factors data,and predict the global outbreak risk of Sudden Oak Death in 2000 by Maxent model.Future climate factors are selected on the basis of the future global climate change trends provided by the IPCC,predict the global outbreak of “Tree flue” in the future(in 2050 and 2070).(2)Analyze the predicted results of the global Sudden Oak Death outbreak risk areas.The forecast results of the Sudden Oak Death outbreak risk area on the west coast of the United States are analyzed.The results indicate that high-risk areas of Sudden Oak Death outbreaks in the West Coast of the United States will expand from the coastal areas of central California,the coastal region of Southwest Oregon,the Puget Sound of Washington,to the entire western coastal region of Washington and Oregon.In the RCP8.5 climate scenario,high-risk areas in the United States West Coast will increase by 174% The results of the prediction of the Sudden Oak Death outbreak risk area in Europe were analyzed.The results showed that the high-risk areas of the Sudden Oak Death outbreak in each period mainly concentrated in the southwestern coastal areas of Great Britain,the northern coastal areas of France,the northern coastal areas of Spain and the northwestern areas of Spain.China’s Sudden Oak Death outbreak risk area of the predicted results were analyzed.The results showed that the risk areas in China are mainly in Anhui,Jiangxi,Zhejiang,Fujian,Guangxi,Guangdong,Yunnan,Sichuan and Chongqing.(3)The Hysplit forward trajectory model and meteorological data were used to simulate the trajectory for a month in July 2007.July 2011.and July 2015 respectively in California,USA.The simulation results and the next year’s Sudden Oak Death outbreak points are conducted an overlay analysis.In the meantime,the same method was used to simulate the four hypothetical outbreak points of Sudden Oak Death at Zhangzhou Harbor in Fujian Province,China for a month(in April 2016).(4)The trajectory simulations in California are analyzed.Simulation results of the propagation trajectory in Zhangzhou,Fujian Province show that Sudden Oak Death will spread from Zhangzhou Port to Zhejiang,Jiangxi and Guangdong.The regions with the frequency of more than 20% are mainly located in the coastal areas of Fuzhou and Xiamen.