Evaluation of urban agriculture multi-functionality development models based on multi-dimension evaluation

Urban development and urban agriculture constitutes an integrated system due to the complicated interaction mechanism of functional complementation and promotion. The multi-functionality of agriculture has been increasingly highlighted during urbanization and the gradual integration of urban agriculture into urban economic, social and ecological development and spatial formation. Urban development, encompassing the natural environment, resource endowment, development foundation and comprehensive strength, is significantly different in the eastern, central and western regions of China. Therefore, diversified development models have been tailored for urban agriculture constantly highlighting the related advantages and characteristics in different regions of China. Evaluating the developing rationality and current characteristics of urban agricultural multi-functionality and exploring the related development models suitable for specific regions are helpful in coordinating urban functions, urban agricultural multi-functions and for formulating urban agriculture development strategies based on region-specific conditions. It is necessary to coordinate the development between urban functions and functions produced by urban agriculture for sustainable development of urbanization areas. We quantitatively assessed urban agriculture multifunction from the aspects of production function, economic function, social function and ecological services in 22 cities of China using a four-dimension evaluation model. We classified and proposed ten development models of multifunctional development of urban agriculture based on the assembly of the related four functions using the system clustering method. The research showed that an individual or comprehensive functions provided by urban agriculture presented obvious differences among the eastern, central and western regions of China. This was due to the differentiation of natural environment, and social and economic development of different regions. From cities in the western region of China to cities in the central and eastern regions, urban agriculture multifunction development models shifted gradually from weakly coordinated development to generally coordinated development and then to strongly coordinated development. It shifted gradually from ecological priority development to predominantly social and ecological development model and then to production, social and economic development model. The development level of ecological services of urban agriculture exceeded 0.40 for cities with the model of ecological priority development. Then, the development level of social functions of urban agriculture was more than 0.55 in cities with the model of social priority development. Next, the development level of economic functions of urban agriculture reached 0.80 in cities for which the model was economic priority development. Finally, the development level of production of urban agriculture reached 0.75 in cities for which the model was provisioning priority development. This series of multi-functional urban agricultural development models suggested that multi-dimensional evaluation method actually reflected the development level of urban agriculture multifunction and the related regional differences in China. Furthermore, it not only provided accurate measurements for evaluation of development degree of urban agricultural functions under different urbanization level, but also clearly indicated the development of the internal structure of urban agricultural services and functions in each city and the related development merits and demerits. The research had important implications for the optimization of urban agricultural multifunction, scientific adjustment of urban agriculture structure, and implementation of coordinated policies on the development of urban agriculture multifunction with the development of urban socio-economy.