The Research On Disaster-shelter Suitability Assessment And Optimized Layout For Urban Green Space

In the process of urban rapid development, many cities face the city disease, such as the environmental deterioration, dense high-rise building, concentrated population, traffic congestions and so on. The problems of city safety crisis are increasingly prominent. The construction of urban disaster prevention, disaster reduction, disaster avoidance and the residents’ demand of disaster avoidance are incongruous. When the urban disasters break out, the resistance of the city is weak, so the security of city residents’life and property are failed to get effective guarantee. As the center of politics, economy and culture, city is concerned for the construction of disaster prevention, disaster reduction and disaster avoidance.Urban green space is an important part of city disaster avoidance place, which not only has the functions of beautifying the environment, maintaining ecological balance, entertainment leisure, sports, science education, but also plays an important the role on disaster prevention, disaster avoidance and relief. Urban green space can provide room for emergency evacuation and post-disaster temporary accommodation when disasters occur. The configuration of emergency disaster facilities and space layout of the urban green space are hotspots for experts and scholars. It has important practical significance for improving the urban security and promoting sustainable development of the city to carry out the suitability evaluation of emergency disaster and urban green space optimization layout of urban disaster-shelter green space.38Greenland patches in Fuzhou main urban area are taken as the research object in this paper. Based on the analysis of the present situation of urban green space construction, Analytic hierarchy process (AHP) and fuzzy comprehensive evaluation (FCE) are used to evaluate the disaster-shelter suitability of urban green space, and realized the quantitative analysis of urban green space planning and construction for disaster-shelter condition. This paper put forward the countermeasures to improve the present situation of urban green space construction conditions. Based on the population and the area of services of disaster-shelter green space, this paper determined service situation of the urban disaster-shelter green space. Combining with the technology of ArcGIS, maximum coverage model was used to get optimization layout for urban disaster-shelter green space. This paper cleared the improvement direction of the existing urban green space construction and planning and layout of new disaster-shelter urban green space in Fuzhou. This thesis gets following basically conclusions:(1) This paper took the safety, efficacy, accessibility and functional into account to analysis the disaster-shelter suitability of the urban green space. Terrain, height of peripheral buildings, fire retardancy of vegetation, width of isolation buffer, distance to high-rise buildings, effectively disaster-shelter area, openness, inner roads, accessibility of residents, accessibility of medical institutions, accessibility of fire control institutions, accessibility of public security agencies, toilets, emergency medical treatment, emergency water supply, emergency tents, emergency power and lighting facilities supply and emergency identified were taken as the evaluation index. Combining with analytic hierarchy process (ahp), index system for the disaster-shelter suitability evaluation on urban green space was constructed.(2)Fuzzy comprehensive evaluation (FCE) is used to realize the evaluation on the disaster-shelter suitability of urban green space. And it turned out that the accessibility of residents, terrain, fire retardancy of vegetation, accessibility of medical institutions, effectively disaster-shelter area of the green space, width of isolation buffer, accessibility of fire control institutions and emergency water facilities are important influencing factors. The most influential factors are terrain and the accessibility of residents. The disaster-shelter suitability of urban green space in Fuzhou was overall well-being, but there are still some differences. Score of Wuyi square on disaster-shelter suitability was highest, which was8.01. Score of Laodongzhe park on disaster-shelter suitability was lowest, which was4.72. Score of other urban green space patches were at a moderate level, which were between five to eight points.(3) Taking the suitability evaluation results of the various disaster-shelter urban green as the basis, the leading causes of the construction difference of each patch were analysised, so as to determine the function of green space around the construction on the shortcomings. The results showed that adding entrances to improve openness, widing the isolation buffer and internal roads, enriching the fire tree species, adding toilets, adding emergency water facilities, adding emergency power and lighting, adding emergency medical facilities and emergency accommodation tent and emergency signs were important measures to improve the suitability of disaster-shelter urban green space. Such as the Wuyi square whose suitability evaluation score was the highest should broad the isolation buffer and add plant fire trees. While the Laodongzhe park whose disaster-shelter suitability evaluation score was the lowest need to add entrances to improve the openness, wide the isolation buffer and internal roads, enrich the fire tree species, add emergency medical facilities, add emergency accommodation tent and emergency signs and so on. Other green space patches can adopt corresponding measures to improve it.(4) Based on the served area and population of urgent disaster-prevention green space, fixed disaster-prevention green space and center disaster-prevention green space, this paper used the functions of network analysis and space overlapping of ArcGIS9.3to analysis the service shadow of urban green space in fuzhou. The results showed that the service situation of urgent disaster-prevention green space and fixed disaster-prevention green space were not optimistic, most of the residents in the northwest of Gulou district, majority area of Jinan district and southeast of Cangshan district are in service blind area. While the center disaster-prevention green space service was in good condition, the residents in the northeast of Cangshan district and local area of the north of Jinan district were in service blind area.(5) Based on the disaster-prevention demand of residents and the goal to service max population and minimum green space patches, this paper used the maximum coverage model to choose layout and address of urgent disaster-prevention green space fixed disaster-prevention green space and center disaster-prevention green space. New66urgent disaster-prevention green space patches were established, the service area was3830.46hm2, which can service240629people. New36fixed disaster-prevention green space patches were established, the service area was7256.15hm2, which can service493844people.