assessment of grain security in china by using the ahp and dst methods

china is one of the largest grain producing and consuming nations in the world and the importance of grain security to the chinese can never be overemphasized. in this paper, we present a comprehensive early-warning model for evaluating the status of grain security in china. the model is based on the analytic hierarchy process (ahp) method and the dempster–shafer theory (dst). we divided the risk assessment into four stages. first, we seek risk sources and identify the indices to be used in the model. then, we preprocess the index data to obtain the index directions and risk bounds. after that, we assign index weights via ahp method. finally, we evaluate risk of grain security via dst method and determine the overall risk degree. an empirical analysis is conducted to demonstrate the use of the model for evaluating the status of grain security in china. the result shows that the model which conforms to the reality of china is effective and can be used as a grain security pre-warning monitoring tool.