Model and Criterion of Urbanization and Ecological Environment Coupling
2005, 25 (4):
Based on Dissipation Structure Theory and the rule of urbanization and ecological environment interaction, the five coupling models which are coordination, basic coordination, threshold, conflict and degradation types have been deduced. According to the models and its evolvement orders, the development paths and trends of the coupling system can been analyzed and forecasted. The threshold is so subtle that we must pay more attention to, or else, the shift from basic coordination to conflict type is dangerous, and the degradation type is so hazardous that we must control and obviate. Through associated analysis and geometrical process, the judgment system to distinguish coordination development has been also put forward on the basis of the coupling models, which is a criterion of evaluating urbanization and eco-environment coordination. If the urbanization comprehensive index and eco-environment comprehensive index are respectively defined as X(t) and Y(t), and differences and the rate of variation defined as ΔX(t), ΔY(t) and ε, the coupling model can be explained on the on a plane. The classifications can be summed up as follows: (1) if ΔX(t)>0, ΔY(t)>0, the coupling system is coordinative; (2) if ΔX(t)=0, ΔY(t)=0 or ΔX(t)>0,ΔY(t)<0, |ΔY(t)/ Y(t-Δt)| =ε, or ΔX(t)<0,ΔY(t)>0, |ΔX(t)/X(t-Δt)| =ε, the coupling system is situated a critical point or a shift threshold; (3) if ΔX(t)>0, ΔY(t)<0, |ΔY(t)/ Y(t-Δt)|<0 or ΔX(t)<0, ΔY(t)>0, |ΔX(t)/X(t-Δt)|<ε, the coupling system is basically coordinative; (4) if ΔX(t)>0, ΔY(t)<0, |ΔY(t)/ Y(t-Δt)| >0 or ΔX(t)<0, ΔY(t)>0, |ΔX(t)/X(t-Δt)| >0,the coupling system is conflictive; (5) if ΔX(t)<0, ΔY(t)<0, the coupling system is degraded. At last as a case, in terms of the models and judgment criterions, Xuzhou city evolved paths and coupling models have been researched by weighted PCA (Principle Component Analysis) from 1992-2002 in order to develop some suggestion. The studies we have performed show that: there are significantly different development paths of urbanization and eco-environment. In Xuzhou, urbanization comprehensive level has continually been advanced but the eco-environment comprehensive quality curve can be regarded as an inverse "U" figure. At the sametime there are four coupling types involved in Xuzhou City, and the coordination & basic coordination types are main ones. With the case studies, it proved the evaluation method and the judgment system which was simple and effective to appraise and coordinated regional urbanization development with eco-environment protection.
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