Urban Emergency Shelter Location Choice And Space Layout

It is the basis for urban harmonious development that public facilities are allocated scientifically and rationally with the aim to maximize efficiency and fairness, so public facility location theory has been concerned deeply by the scholars from various fields such as geography, economics and management. Existed literatures are mainly in qualitative research and little in quantitative research, and in those quantitative studies, mostly limit to figure theoretical models and discuss algorithm but seldom combine theory with empirical case.At the same time, the evaluation of spatial distribution reasonability about public facility is still in the exploratory stage without forming a unified or universally standard. Thus, researches of public facility location theory are abundant but still deficient in the combination of empirical research to guide the spatial distribution of specific public facility. Being worth pointing out that systemic research framework has not been formed from the public facility location theory, location choice to adjustment and optimization, rationality evaluation of spatial distribution in the field of public facility location research. Based on this, this paper takes urban emergency shelter as the object of study and under the above systemic research framework tries to research its location choice and spatial distribution combining with empirical case.This paper firstly defines the connotation of urban emergency shelter, and summarizes the types and related standards of planning and construction of urban emergency shelter. On the basis of summing up related studies of public facility location theory, this paper then indicates that the welfare theory and public goods theory in economics as well as location decision-making analysis of public facility in geography and management science can be used to direct the location choice and spatial distribution of urban emergency shelter. Lastly, this paper concludes some related theories, such as the theory of welfare economics, public goods theory, fairness and justice theory, location theory and public facility location theory.During the quantitative process of public facility location research, the selection and construction of the location model are the most critical links. Based on analyzing the applicability of facility location models, four type models of public facility location choice are generalized, which are the basis to build location models of urban emergency shelter in different levels.Taking P-median problem as the basis of the location model for fixed refuge and maximal covering location problem as the basis of the location model for center refuge, the models can be achieved by means of adding corresponding restrictions, respectively. Putting the constructed models into the location choice of seismic shelter for evacuation in Nanjing and combining location optimization rules of seismic shelter for evacuation, the location optimization schemes of Nanjing seismic shelter for evacuation on different levels can be gained.Through dividing the service range and configuring the people scale, the spatial distribution scheme of emergency shelter comes true on the basis of location choice and optimization of urban emergency shelter, and the empirical study takes Nanjing as an example. First of all, with the goal that the residents can quickly and efficiently reach the nearest refuge at the moment of disaster, the model of service range division and the configuring method of people scale within the service scope of emergency shelter are raised. Secondly, applying the above methods to Nanjing, the spatial distribution schemes are realized after dividing the service range and allocating the people scale of groups’and center seismic shelters for evacuation, separately. Finally, by the contrast of existing scheme and original planning, the effectiveness of the above models can be verified.Spatial distribution of public facility has direct impact on the service results for citizens. Firstly, this paper clarifies the definitions of the fairness and reasonability of spatial distribution for public facility. Then, from the perspective of accessibility, this paper constructs six indices which are service area ratio, service population ratio, average accessible emergency shelter area, population gap of emergency shelter, service capacity ratio and service overlap ratio. Lastly, using the six indices and network analysis based on GIS, this paper analyzes the accessibility, equity and efficiency of urban emergency shelters and further estimates its rationality of spatial distribution. The results show that the rationality of spatial distribution of groups’ seismic shelters for evacuation is higher than that of center seismic shelters for evacuation in Nanjing.Emergency shelter is an important barrier for the city against all kinds of disasters. Whether it’s layout is reasonable or not, it will have an important impact on urban safety. First of all, the main problems of emergency shelter in the course of planning and construction are summarized at home and some recommendations and countermeasures are made. Then the layout principles of emergency shelters with different types are analyzed according to its function, so as to guide the reasonable configuration of urban emergency shelter from a macro perspective. And finally, some issues in connection with the layout of urban emergency shelter planning have also been discussed.Drawing the facility location models and algorithm in mathematics and operational research into the process of location choice of urban emergency shelter, location models and optimization methods of spatial distribution for urban emergency shelter are constructed based on the location theory of public facility, and then spatial distribution schemes of urban emergency shelter are formed. Meanwhile, evaluation indices and method of spatial distribution rationality for urban emergency shelter are put forward in this paper. Moreover, empirical research verifies that the models and methods are scientific and effective. In briefly, the related results enrich the content of public facility location theory, perfect the methodology system of public facility location research, provide a new approach for location decision-making analysis of public facility, and offer the theoretical guidance and methodological reference for location choice and spatial distribution of emergency shelter in other cities.