Study On The Optimization Of The Layout Of Disaster Prevention Shelters Of The Reservoir Cities In The Post-three Gorges Period

Since entering the post Three Gorges period,the urban planning and construction of the Three Gorges Reservoir area has been accelerated,which has promoted the socioeconomic growth,population migration,land transformation and the re establishment of ecological environment balance.Reservoir cities have always been prone to various kinds of natural disasters.The impoundment operation of the Three Gorges reservoir has changed the fragile hydrogeological conditions of the reservoir area,intensified the occurrence of landslides,collapses,debris flows,floods,earthquakes and other disasters,resulting in more complex disaster prevention and control status of the reservoir cities.As an important public service facility for urban disaster prevention and mitigation,the reasonable layout of disaster prevention and refuge places will greatly affect the pre disaster prevention and post disaster rescue ability of the reservoir cities.However,due to the limitation of social and economic factors,the construction of disaster prevention shelters is generally lagging behind,and the problem of disaster prevention is generally prominent.Therefore,the research on the planning and layout of disaster prevention shelters is the key problem to be solved in the urban and rural planning and construction of the reservoir area.In this context,the paper takes the disaster prevention shelters in the reservoir area city as the research object,and takes the problem-oriented as the research idea,and makes an investigation and comprehensive analysis of the spatial environment,disaster types,disaster characteristics and the current situation of the construction of disaster prevention shelters in the reservoir area city in the post Three Gorges period.It is found that the comprehensive response capacity of the reservoir area city to multiple disasters is insufficient,and the focus should be on the construction of the center,fixed Three levels of emergency shelter system.Based on this,the paper combines the theories and methods of related disciplines,relying on the mathematical model and GIS technology,constructs the research ideas and planning technical process of multi-level disaster prevention shelters layout optimization in the reservoir area city,and takes Zigui and Badong as the typical cities in the reservoir area as an example to study the research results.The layout optimization scheme can provide the planning and layout of disaster prevention shelters in the reservoir area city More scientific basis.The main contents of this paper are as follows:1)In this paper,the key problems of planning disaster prevention shelters in the reservoir area are analyzed in detail.Based on the investigation and Research on the characteristics of urban spatial environment,the types and characteristics of disasters in the reservoir area and the current situation of disasters in the reservoir area in the post Three Gorges period,this paper summarizes the three characteristics of urban disasters in the ex warehouse area,which are multiple types,wide distribution,seasonal concentration and natural disaster chain.Based on the investigation of the current situation of the disaster prevention shelters in the reservoir area,it is concluded that there is a lack of reasonable layout of the disaster prevention shelters in the reservoir area,and the small and medium-sized emergency disaster prevention shelters are obviously insufficient,which leads to the lack of comprehensive response capacity for the current situation of multiple disasters in the reservoir area.Combined with the relevant theoretical research results and construction practice at home and abroad,this paper puts forward that the key problem of building a multi-level disaster prevention shelter system should be focused on the comprehensive response of multiple disasters in the urban disaster prevention shelter in the reservoir area,and studies and discusses the planning technical indicators of the urban disaster prevention shelter in the reservoir area.2)A multi-level optimization method for the layout of disaster prevention shelters in the reservoir cities is established.Based on the investigation of disaster prevention in the reservoir area,three principles of safety,effectiveness and accessibility are determined as the layout optimization principles of disaster prevention shelters in the reservoir area.Under the guidance of these three principles,this paper constructs a three-step layout optimization technical method,which is based on the evaluation of the suitability of land use for disaster prevention and refuge,the site selection and zoning of disaster prevention and refuge,and the verification of the accessibility of disaster prevention and refuge.Firstly,the suitability of land use for disaster prevention shelters within the research scope is evaluated by comprehensively considering the terrain slope,potential disaster points and major hazard sources The selection and addition of disaster prevention shelters provide a more scientific basis.Then,based on the two basic location models,the set covering model and the p-median model,combined with the actual constraints such as the service radius,the location and responsibility area division model of disaster prevention shelters in the reservoir area are constructed.Based on Arc GIS platform,the model is solved to realize the site selection and responsibility area division of disaster prevention shelters at all levels,and calculate the coverage rate of refuge demand points and the service rate of refuge population in each responsibility area.If the corresponding index requirements are not met,new disaster prevention shelters or expand the scale of existing disaster prevention shelters will be added.Finally,the accessibility evaluation method based on the average minimum impedance is selected,and the network analysis tool in GIS is used to evaluate the accessibility of the layout optimization results and generate the accessibility distribution map.Through the comparison of the current situation and the accessibility of the optimized layout of the disaster shelter,the results of the optimization of the layout are verified,and finally the layout optimization scheme of the disaster shelter in the reservoir area city is obtained.3)Taking Zigui and Badong as examples,this paper makes an empirical study on the layout optimization of disaster prevention shelters.In this paper,Zigui and Badong,the typical cities in the reservoir area,are selected to make an empirical study on the three levels of disaster prevention shelters,namely,the center,the fixed and the emergency.Compared with the current layout of disaster prevention shelters,the coverage and accessibility of all levels of disaster prevention shelters in the layout optimization scheme have been significantly improved,and can meet the requirements of the service rate of the asylum population within the scope of each responsibility area.The results of the empirical study on the layout optimization are reasonable and effective,which can provide a scientific basis for the planning and layout of urban disaster prevention shelters in the reservoir area.Finally,combined with the empirical research program of layout optimization,this paper puts forward some suggestions on the planning and construction of urban disaster prevention shelters in the reservoir area.