| From time immemorial,the food security and people’s livehood are closely interrelated.Currently,there are three problems of food security in Hohhot,which includes the low rate of food self-sufficient,the unreasonable makeups of varieties and the increasing gap between food supply and demand.Based on the perspective of supply side,grain yield safety is the basis of all.In this paper,I researched the trend of grain yield and the fluctuation of grain yield respectively with the angle of short-run fluctuation and long-run fluctuation.And also,I did an empirical research on the factors which effect the fluctuation of grain yield.Firstly,I made a quantitative analysis of the characteristic on the grain yield fluctuation.1.I studied the period,amplitude and types of fluctuation of grain yield by fluctuation index.2.I studied the fluctuation contribution rate of varieties to the total by variance decomposition.3.I studied the fluctuation of grain yield in different regions by EMD(Empirical Mode Decomposition)algorithm.Secondly,based on the research above,I focused on the factors which effect the fluctuation of grain yield.According to the forming mechanism of the fluctuation,I studied the climate(seasonal)effect and factors input on grain yield fluctuation by AHP(Analytic Hierarchy Process).And also,I acquired the degree and the trend of the influence of each index on grain yield fluctuation.Finally,I draw the conclusion as follows.1.Climate is the key factor on fluctuation of grain yield,and they have the same cycle.2.There has a trend that capital substitute agricultural,which is based on the urban and rural economic structure.3.Diversified planting structure is conducive to reducing grain yield fluctuations,and also help to resist the risk of fluctuations.According to the conclusions above,the following suggestions are put forward.1.Improving agricultural infrastructure,especially on the construction of irrigation and water conservancy.2.Increasing agricultural capital investment.3.Optimization of agricultural planting structure.4.Improving grain production detection and early warning mechanism.5.To speed up the enactment of the "Grain Law". |
