Study On The Fluctuations In Grain Production And Yield Trend Of Jinan City

The grain is the basic subsistence of human in survival and the development, it is the raw essential material for industry of many national economy department. Especially in China, the such large population, and industrialization development phase, the grain has the special significance. Since founding of the nation, the grain yield of Jinan enhances rapidly, but food production's growth is not a stable change process, but increases in the fluctuation. Jinan's food production fluctuation directly relates Jinan's food production continuing to grow stably, affects its stable grain supplies ability and agricultural sustainable development path's smooth advance. Therefore this article chooses the Jinan food production fluctuation question to carry on the research discussion, It may provides the rationale for Jinan grain yield steady growth and the scientific basis for Jinan to formulate the correct food production policy.This article mainly uses Jinan statistical annual of 1997-2006 year, Jinan economy and social development of 1949-1989 year and Jinan Land Resources Bureau datas, it carry on the analysis of Jinan food production fluctuation from the grain per unit area yield, the grain sown area and grain ultimate output. It used the wavelet analysis method and the BP artificial neural networks method to carry on the forecast to the grain yield tendency. The conclusion is as follows:(1) It is of the primary importance of the fluctuation of meteorological phenomena factors in agriculture in the fluctuation of per-unit-area yield of grain. There are the other factors, such as the Grain crops planter structure and strains of grain etc.(2) There are several factors,such as the country institutional innovations and macroscopic policy, market factor, natural disaster, which have great effect on the fluctuation of total areas of grain.(3) The per-unit-area yield of grain has primary effect on fluctuation of grain yield from 1949 to 2005, reaching 70.94%, after the 80s, the area fluctuation has to the total output fluctuation's influence strengthens the tendency, which means that the proposition of total areas of grain is on the rise. (4) This article uses the wavelet analysis to carry on the much time criterion analysis to the Jinan grain yield change; it has carried on the forecast to the Jinan grain yield future trend. The results show:①the grain yield has 6 years, 14 Years and 20 years, characteristic time scales and corresponding changes from the figures of the wavelet coefficients. At the meantime, the time scales tend to become longer and it indicates that the change of the grain yield of Jinan become steady step by step.The grain yield has the 6 years and 14 years main periods from the wavelet variances analysis, and the 14 years period is especially outstanding. Whether at the big scale or at the small scale, the grain yield in Jinan seems to be increasing in the recent years form the analysis of the figures of the wavelet coefficients.(5) This article utilizes the training BP artificial neural networks to forecast that Jinan grain ultimate output in 2010, 2020 respectively is 268.64×104t, 276.02×104t, the food production assumes the growth movement, and the forecasting result is consistent with the wavelet analysis method(6) According to Jinan food production fluctuation characteristic, this article puts forward the following proposal to weakened the Jinan food production fluctuation: practical protection farming, stable grain crops sown area; increases the agricultural investment, promotes the agricultural land intensive use; introduces the 3S technology, strengthens the monitor; the formulation suits the grain steady growth the policy; strengthens the agricultural science and technology the promotion.