Simulation And Optimization Of Agricultural Industry Structure In Zhucheng City Based On System Dynamics Model

This research takes Zhucheng City of Shandong Province as the study area,based on the agricultural industry structure data for 12 consecutive years from 2005 to 2016,constructs a system dynamics model of agricultural industrial structure,predicts the trend of agricultural industrial structure in Zhucheng City in 2017-2035 and conducts multiple scenarios.Simulation analysis of the findings was done coupled with proposed optimization adjustment.The main findings are as follows:(1)The system dynamics model of agricultural industrial structure in cities is constructed.Based on the related concepts of agricultural industrial structure and system dynamics,as well as the basic theories of industrial structure.This paper analyzes the inter relationships and differences between planting,aquaculture,agro-processing and leisure agriculture in cities.The Vensim PLE software was used to map the three module stock flows of the planting subsystem plus the planting and binding subsystem including the processing and leisure subsystem.Analyzed each variable relationship and indicator data.Mathematical equations in which the variables of the model interact with each other was done by means of multivariate statistical regression to calculate the relevant parameters involved in the equation.Finally,a system dynamics model of agricultural industrial structure in cities is constructed.After the model test,the simulation results are consistent with the actual economic and social development of the cities indicating the model has good reliability.(2)Simulating the development of agricultural industrial structure in the cities of 2017-2035.The research results show that by 2035,the area planted with food crops will be reduced to 110,500 hectares whiles area planted with economic crops will increase to 65,200 hectares and livestock and poultry will reach 5,911.9 thousand tons.The utilization rate of livestock and poultry manure increased from 74.30% in 2016 to 89.87% also the new types of agricultural businesses of the combination mode of crop and livestock industries has increased to 7,667.Total agricultural output value reached 25.132 billion yuan with the output value of the food processing industry increasing to 125.263 billion yuan.The output value of leisure agriculture also increased from 2.148 billion yuan in 2016 to 4.112 billion yuan in 2035.However,in general the proportion of high-efficiency agriculture in cities is low with the scale of each industry being low.There is no link between the crop and livestock industries,which implies there is the need for further improvement in resource utilization in this sector.The industrialization level of fruits,vegetables and tea is low.Subsequently the integration of the first,second and third industries must be prioritized.(3)Completion of industrial structure simulation analysis under multiple scenarios.After optimization,the output of grain crops reached 961,300 tons by 2035;compared with the pre-optimization,the output increased by 57,600 tons.The output of cash crops reached 1,801,700 tons by 2035;compared with the pre-optimization the output increased by 281,400 tons,1.5 times than that of 2015 with a total of 2,572 households have been added to the new types of agricultural businesses of the combination mode of crop and livestock industries.The utilization rate of livestock and poultry manure will reach 98.6%;which will increase by 8.73% compared with before optimization.Compared with before optimization,the value of food processing increased by 73.521 billion yuan compared with the optimization,with a growth rate of 58.69% with the total agricultural output value recording 27.585 billion yuan.The ratio of the output value of agricultural products processing industry to the total agricultural output value reached 4.1:1 from 3.25:1 before optimization.(4)Proposing policy recommendations for the development of agricultural industrial structure in Zhucheng City.The results obtained from the optimization simulation stimulates four key recommendations for promoting the optimization of agricultural industrial structure in cities and towns.The First is to strengthen agricultural planning and rationally adjust the agricultural layout.Secondly,increase investment in science and technology and improve agricultural efficiency.Thirdly is to develop a nutrient management plan,accelerate the development of the combination mode of crop and livestock industries.Lastly is to support new types of agricultural businesses and promote industrial integration.