基于复杂性科学的绿洲城镇化演进理论探讨

Mechanism of oasis urbanization: A theoretical framework based on complexity theory

基于复杂性科学,引入涌现、协同、"吸引盆"等概念和模型,从涌现生成、协同维生、临界相变三个维度构建绿洲城镇化演进的理论框架。对绿洲城镇化的生成、演化和转型的过程与机理进行系统剖析,并据此对诺瑟姆曲线进行新的解读。研究表明:1绿洲城镇是以人为核心的绿洲地域系统在多时空维度上的结构和功能的整体涌现现象,涌现形成的条件包括生成主体、自组织与受限生成机制、环境策略;2竞争与协同机制维持了绿洲城镇化系统的生命活力与进化稳定,是系统演化的根本动力,系统不同层级具有不同的协同维生机制,根据协同学和耗散结构理论构建的绿洲城镇化演进的协同度和有序度可以识别系统演化方向;3绿洲城镇化过程实质上也是系统的自组织临界相变,该过程是一个渐变与突变、有序与混沌、稳态与非稳态的辩证统一;4时空间的正负反馈机制使绿洲城镇化复杂性与有序性不断提高,且不断向自组织临界态靠近,城镇化系统外在表现为活力与多样性增强。

Oasis cities are the most concentrated zones of human activity and the most vulnerable places in the arid region of northwest China. The urbanization rate rose from 15% at the beginning of the reform and opening up to 44.75% in 2013. Oasis urbanization is a typical complex giant system, featured with nonlinearity, self- organization, self- adaptability,fluctuation and feedback. Research on the mechanism of oasis urbanization is significant for the planning and construction of new- type urbanization in China’s arid areas. Based on complexity theory, we analyzed the generation, evolution and transformation process of oasis urbanization, and built the theoretical framework of oasis urbanization evolution mainly from three dimensions of the emerging generation, coordinated sustenance and critical phase transition innovatively, by using proper concepts like emergence and synergism and the model of basin of attraction, according to which the Northam Curve was reinterpreted. The study indicated that：（1） Oasis city is an entire structural and functional emergence phenomenon of a human- centered oasis region system from the perspective of multiple spatial and time dimensions, and its formation conditions include generating subjects, self- organization and limited formation mechanism and environment policy.（2） Competitive and synergic mechanisms keep the vitality and evolution stability of the oasis urbanization system, which is the basic motive force of the system evolution. According to the synergetics theory and dissipative structure, we build the synergy degree and order degree of oasis urbanization evolution to recognize the evolution direction of such system.（3） Oasis urbanization process is also essentially a self- organized critical phase transition, which is the dialectical unity in the aspects of rheology and mutation, order and chaos, stability and non-stability.（4） The positive and negative feedback mechanisms in space and time improve the complexity and order of oasis urbanization, which approaches to the state of self- organized criticality; meanwhile, the vitality and diversity of urbanization system are reinforced in this process. Furthermore, the complex system models, such as multi- agent model, the complex adaptive system model,bionic calculation and social computing, will play an important role in the research of urbanization simulating and forecasting.