Evolution of Cultivated Land Security System in Jiangsu Province based on Information Entropy
基于信息熵的江苏省耕地安全系统演化分析

The Cultivated Land Security System comprises natural and socioeconomic subsystems.The direction of system evolution is often determined by economic value and benefits of the system's outputs,which cannot fully describe the flows of substances,energy,information and population.Based on dissipative structure theory and cultivated land security system(CLSS) theory,the indicator system for evaluating cultivated land development,and the appraisal model for measuring various material flows in cultivated land security system were set up.Furthermore,the annual-based and indicator-based information entropies were obtained in CLSS.Three types of information entropy,including quantity change entropy,quality change entropy and environmental change entropy were calculated by annual-based information entropy to analyze the order and complexity of CLSS.The weights of indicators evaluating CLSS were calculated and the index scores of CLSS were calculated by standardization values of indicators.Index values of cultivated land security system could be applied to identify the development level and degree of harmony of CLSS.Employing the measuring method,the progress of cultivated land security system development in Jiangsu from 1998 to 2004 was described.The results show that the pressuring entropy and supporting entropy concerning cultivated land quantity,quality and eco-environment change violently,with features of entropy change from positive to negative in cultivated land quantity,input-output equilibrium in quality and fluctuation in eco-environment.The total entropy of cultivated land security was increasing firstly and then decreasing from 1998 to 2004,indicating the increased degree of order of CLSS.The development and harmonious degree of CLSS has a significant difference.The development degree of quality and quantity ranks the advanced level with a decreasing trend,while the eco-environment development changes from intermediate to advanced level.As far as the harmonious degree is concerned,the minor change of quantity and quality harmonious degree contrasts to the obvious oscillation of eco-environmental harmonious degree.The leaning harmonious degree of the quantity change varies from strong socioeconomic pressure to strong capability and the leaning harmonious degree of the quality changes from intermediate supporting to intermediate pressure,and the leaning harmonious degree of the eco-environment changes from intermediate socioeconomic pressure to strong supporting.The result of analyzing entropy flow and development and harmonious degree means that the healthy and orderly level of CLSS in Jiangsu has increased,and the coordinating capability has been improved simultaneously.