Location And Layout Research Of Landslide Emergency Shelters Based On GIS

With the rapid development of China's economy and the continuous advancement of urbanization and industrialization,the spatial scope of human activities has gradually expanded from the eastern plain to the western mountainous areas.The over-exploitation of human beings has caused the destruction of vegetation on slopes and the intensification of soil erosion,which has resulted in frequent geological disasters.Landslides,as the main type of geological hazards,have been increasing in frequency and intensity in recent years,causing great losses to people's lives and property.The location of emergency shelters,as an emergency disaster prevention and refuge action,plays an important role in the pre-disaster and post-disaster recovery stages.However,there are still many problems in the actual study of the location and layout of emergency shelters,such as the single selection of the optimization principle of the shelter layout,the lack of an emergency service facility location model which takes into account the economy,efficiency and fairness of the location,and the failure to consider the impact of landslide disaster points on the safety of the shelter layout.Thirdly,there is a lack of indicators and models to evaluate the layout effect of landslide emergency service facility location model.Therefore,in geological hazard prone areas such as landslides,it is extremely necessary and urgent to plan and layout emergency shelters scientifically and evacuate people timely and effectively.As one of the most serious geological hazards in China,such as landslides,landslides and debris flows,the economic losses caused by landslides in the Three Gorges Reservoir area are more than 1 billion yuan each year,accompanied by casualties.Therefore,it is of great socio-economic significance to optimize the layout of landslide shelters in the Three Gorges Reservoir area.Based on this,this paper only takes Zigui County in the Three Gorges Reservoir Area as the research object,through analyzing the formation reason,occurrence mechanism and spatial distribution law of regional landslide disaster,and combing the related literatures such as risk assessment,location of emergency shelter and so on,determines the location distribution principle of landslide disaster emergency shelter.The model and algorithm are based on the basic principles of location layout such as security,accommodation and accessibility,and the objectives of minimizing the number of shelters,maximizing the balance of personnel allocation and minimizing the total evacuation distance under complete coverage are considered in detail.Based on the location evaluation model and layout optimization model proposed in this paper,combined with GIS spatial segmentation Analyzing and multi-objective evolutionary algorithm,seven Pareto location placement schemes are obtained,and the performance of the algorithm is evaluated by the average evolutionary rate,the dispersion of non-inferior solution distribution and the diversity of solution space distribution.The performance shows that the convergence of the index such as the diversity of solution space distribution,the average evolutionary rate and the dispersion of non-inferior solution distribution is good.The rationality of the parameter setting of the standard evolutionary algorithm and the validity of the generated non inferior solution set.In order to compare the impact of disaster point distribution on the relief effect of emergency shelter layout under different location and layout schemes,this paper first finds the optimal decision-making scheme reflecting the different target orientation of decision-makers through the method of stochastic multi-attribute acceptability analysis,and then uses the comprehensive vulnerability evaluation model to evaluate the shelter of each decision-making scheme.Risk assessment of disaster losses in service areas is carried out,and emergency synergy ability index of refuges is introduced to evaluate the emergency synergy ability of each refuge when dealing with regional risks,and the most reasonable scheme to make the layout of refuges in the region more effective in disaster relief is studied.The results show that the "priority of shelter evacuation distance" scheme has a shorter shelter distance,which can make the residents of disaster-stricken areas arrive at the shelter as soon as possible to avoid risks,while the "priority of shelter number" scheme needs fewer shelters,which can effectively reduce the cost of infrastructure maintenance.However,the two schemes have different shelter locations.The unreasonable distribution and unbalanced distribution of disaster sites have resulted in poor synergy in the process of dealing with regional risks;while the "balanced priority of personnel distribution" scheme is more compromised than the other two schemes in terms of quantity control,balance of personnel distribution and total evacuation distance,and avoids each other.When dealing with regional risks,the emergency coordination ability is better,and it is the most reasonable scheme for the layout of refuges in the region.In this paper,the optimal scheme("balanced priority of personnel distribution")and the existing layout scheme are compared,and according to the problems of unreasonable shelter location,imperfect maintenance and management mechanism,and poor coordination ability of regional disaster emergency response in the current work of landslide disaster prevention and control in this region,the paper puts forward the disaster emergency linkage mechanism to improve under the background of disaster emergency response.The countermeasures and methods for disaster relief and mitigation in this area include the selection of layout principles and layout models,the consideration of uncertainties,the solution of model algorithms and the evaluation of layout effects.Thus,a set of scientific,complete,pertinent and operable emergency service facility location scheme is established.