The early warning system of environmental quality in production base of green food supported by GIS—A case study from the national ecological agriculture demonstration area in Qing’an County，Heilongjiang Province

Taking the production base of green food，the national ecological agriculture demonstration area in Qing’an County as an example,this paper forecasts the occurring probability of environmental quality status in the coming five years and analyzes the early warning of environmental quality negative evolution and the early warning of aggravation speed by adopting the Markov chain model.The results show that the early warning signal of negative evolution has been given by the environmental quality in Jubao Village,Dongyang Village and Nihe Farm located in the studied area.And the environmental quality aggravation speed is the fastest in Jinxing Village,Hongxing Village,Jianye Village,Jianmin Village,Shuangli Village and Dongyang Village.Finally,the solving countermeasures are put forward.