Geographical Calculation Of Optimizing Location Of Public Service Facilities In Rural Areas

How to scientifically locate public service facilities in rural areas and improve the service level of public service facilities is one of the important tasks to realize the strategy of rural revitalization.In view of the needs of rural construction in China and considering the characteristics of limited financial expenditure and low traffic accessibility in environment areas,this study uses the facility location-network design method to solve the problem of optimal location of public service facilities in mountainous villages.The facility location-network design method not only pays attention to the location of facilities,but also emphasizes the optimization design of traffic road network.At the same time,this paper improves the traditional facility location-network design method,divides the original single objective into multiobjective,and introduces multi-objective optimization theory to solve the facility location-network design problem.In addition,the classical facility location-network design model does not consider the situation that the road can be upgraded.This paper constructs a multi-objective facility location-network design model with three road scenarios(only consider the existing road,assume that the road can be upgraded and the road can be built or upgraded).The location optimization of rural public service facilities is different from that of urban public facilities.In the process of building the model,we must consider the accessibility of roads,the ruggedness of roads and the limited level of financial expenditure in rural areas.Thus,the multi-objective models are constructed for facility location-network design problems based on gravity center model,facility location-network design problems based on coverage model and public facility location-network design problems based on neighborhood avoidance model respectively,and robust optimization method is used to solve facility location-network design problems considering uncertainty.(1)The problem of rural public facilities location-network design based on the gravity center model is analyzed with the rural school location as a case study.In the process of building the model,two factors are mainly considered.One is to ensure that the travel cost(time spent)of students to school is the least,the other is to ensure that the cost of school facilities construction and road construction and upgrading is the least.The objective function of center of gravity model is mainly used to ensure that the total time spent by all residential students arriving at the nearest school is the least.Based on this,a multi-objective facility location-network design model including three road scenarios is constructed to minimize the cost of student travel,facility construction and road upgrading.(2)The location optimization of rural medical emergency facilities is selected as a case to analyze the problem of facility location-network design based on coverage model.In the process of building the model,three factors are considered,the first is to minimize the penalty value of the uncovered residential areas;the second is to minimize the total time spent by all the residents to reach the nearest medical emergency center;and the third is to minimize the construction cost of the medical emergency center and the cost of road construction and upgrading.Coverage model is used to determine whether the residential areas(demand points)are within the coverage of medical emergency center facilities.If the residential areas are within the coverage,they will not be punished,otherwise they will be punished.The objective function of coverage model is to minimize the penalty cost of uncovered residential areas.Based on this,a multi-objective facility location-network design model with three road scenarios is constructed to minimizing the penalty value of uncovered residential areas,minimize the time spent on patients arriving at the medical emergency center,minimize the cost of facility construction and road upgrading.(3)The location optimization of rural garbage transfer station is selected as a case to analyze the problem of facility location-network design based on neighborhood avoidance model.In the process of building the model,three factors are considered,the first is to ensure a certain distance between the refuse transfer stations and residential areas,the second is to minimize the total cost of refuse transport in all residential areas,and the third is to minimize the construction cost of refuse transfer stations and the cost of road construction and upgrading.The anti-center model is used to describe the neighborhood avoidance problem of rural refuse transfer station,that is,to ensure that the Euclidean distance from the nearest residential area(demand point)of the refuse transfer station is the largest.Therefore,the objective function of the anti-center model is chosen as one of the objective functions of the multi-objective location-network design model of adjacent avoidance facilities.Based on this,a multi-objective locationnetwork design model of adjacent avoidance facilities with three road scenarios is constructed.(4)Because there are many random and uncertain factors in the location of public facilities,we need to deal with them through uncertainty theory.Taking the location of rural medical emergency facilities as an example,this paper mainly considers the influence of weather conditions and other natural conditions on the time of medical emergency treatment,and constructs a multi-objective model aiming at minimizing the penalty value,the travel cost of patients in residential areas,the construction cost of medical emergency centers and the cost of road construction and upgrading.The multiobjective model is transformed into a single objective,and then the p-robust optimization method is used to construct a robust optimization model under uncertain travel cost.The model also contains three road scenarios.In terms of geographic calculation method,the search efficiency of simulated annealing algorithm is limited.Therefore,based on simulated annealing algorithm,this paper absorbs the idea of group search,mutation and crossover of genetic algorithm,and combines with fast non-dominated sorting approach,proposes an improved multiobjective simulated annealing algorithm(IMOSA).The IMOSA algorithm overcomes the problems of low search efficiency and limited precision of traditional multiobjective simulated annealing algorithm.To verify the feasibility of the algorithm,the algorithm is applied to practical cases,and the results show that it can effectively solve the multi-objective facility location design model.The results show that the efficiency of students' schooling,medical first aid and garbage transportation has been gradually improved from road scenario 1 to road scenario 3,and the number of residential areas not covered and the cost of garbage transportation have also been gradually reduced.In addition,by comparing the results of three scenarios,it is found that the traffic network conditions have an important impact on the location of rural public service facilities.Rational improvement of traffic conditions can effectively improve the service level of rural public facilities.To verify the effectiveness of the proposed algorithm and model,this study used geographic information science method,take Visual Studio.Net 2010 as the development platform,use C# language,MATLAB language and ArcGIS Engine 10 component library to develop a location optimization system of rural public service facilities based on transportation network.Finally,the system has been applied to the location optimization of public service facilities of in Guizhou province(taking the location of rural schools,medical first aid and garbage transfer stations as an example).The system provides assistant decision support for rational planning and location of public service facilities in mountainous and rural areas.