竞争型公共设施区位决策——概念、选址原则及模型构建

竞争型公共设施竞争性、公益性并存,其区位决策相对更加复杂。首先提出了“竞争型公共设施”的概念,指出“兼顾效率与公平的空间均衡”是其选址的基本原则,并概括出具体选址要求：遵循供需双方的空间相互作用模式、限制至邻近设施的最大出行成本、追求总出行成本最小化、约束设施规模门槛、与低层级设施在出行成本上相区分等。其次构建了基于概率分配规则的重力P中值模型,通过纳入设施规模因子实现区位和规模同步求解,并对邻近设施最大出行成本和设施最小规模进行约束,以实现空间公平-效率、服务质量公平与规模效率等多重目标。最后经过实证检验,优化后的设施布局更为均衡合理。

Competitive Public Facilities Location Decision: Concept,Location Selection Principle and Model Construction

Competitive public facilities are both public-welfare and competitive, among them the comprehensive hospitals are most representative. Their location decision is relatively more complicated. This study aims to solve the problem that how to seek the optimal locations of such facilities. First of all, this study puts forward the concept of “competitive public facilities” which had been not defined systematically and normatively, pointed out that “the spatial equilibrium to coordinate the efficiency and equity” is the basic principle in location selection of competitive public facilities, and summarized a series of location requirements that they are to abide by the spatial interaction between the supply and demand, to limit the extreme travel cost from the settlement to the nearest facilities, to minimize the weighted total travel cost, to restrain the facility scale threshold, and to distinguish appropriately in spatial distribution between the higher level competitive public facilities and the ones. Secondly, gravity P median model was constructed with the probability distribution to replace the proximity rule by embedding the improved Huff probability model in the classic P median model. In such new model, the facility scale factor was introduced to solve facilities location and scale simultaneously, and then two factors were constrained that they are the biggest travel cost from some settlement to the corresponding nearest facility as well as the minimum facility scale. The objective function and a series of constraints just been mentioned can guarantee to realize the multiple targets including the spatial equity—efficiency, quality of service fairness and scale efficiency. Finally, the model was applied to the empirical test as to the comprehensive hospitals location decisions in Wuxi urban district, the results showed that: 1) The optimal facilities distribution is more balanced, and new hospitals locations form three layers that are the main core, secondary core and outer layers, which can comprise reasonable structure with more appropriate division, meanwhile the scale configuration of hospitals is in conformity with the population distribution on the whole. 2) The spatial equity of the optimal locations calculated with the new model shows bigger advantage, since a class of related indicators are improved that they are the Gini coefficient of available service resources quantity potentially for residents and other such indexes. 3) And at the same time, it is decreased properly that is the weighted average travel time from the settlements to all the hospitals, which can achieve the collaborative layout and spatial mismatch among the hospitals and the community health service organizations. In addition, it is important to note that this study focuses on the discussion of theory and approach, rather than the application with the intact model. Futhermore, when the new model is applied to the actual planning and location selection, concerned parameters and constraints should be adjusted appropriately by planning situation. All in all, the above study can support certain decision basis for future public facilities distribution adjustment or new town construction, meanwhile can enrich the concerned research about public facilities location allocation both here and abroad.