Study On GIS And GA In The Selection Of Mountainous Village Natural Environment Suitability For Human Settlements ——A Case Study Of Yuanyang County

Since ancient times,human beings have tended to seek areas with superior natural environment conditions to settle down.However,the natural environment on the earth's surface is complex and diverse,and the mountainous areas is more complex.The selection and reasonable planning of areas suitable for human settlement have become an important part of regional development.It is a multi-objective optimization problem in spatial planning to search mountainous rural livable areas under various natural conditions.The simple spatial optimization problem can be solved by using GIS spatial analysis function.However,natural environment for human settlements involves many factors,the amount of spatial data is large,and using GIS spatial analysis need many times.There is a large amount of data storage in the process of operation,and the application of intelligent genetic algorithm(GA)and GIS in complex multi-objective optimization can save a lot of time,and reduce the amount of intermediate data storage in the process of data processing.In view of the selection of natural environment for human settlement suitable area in mountainous rural,on the basis of GIS spatial analysis,using the characteristics of parallel operation of genetic algorithm,the algorithm can be quickly selected in a large spatial range,which provides technical means and theoretical support for solving complex multi-objective planning and location problem.Based on the characteristics of mountainous areas in Yunnan Province,this paper takes Yuanyang County,Honghe Prefecture,Yunnan Province as an example to build the suitability evaluation model of natural environment for human settlements in mountainous rural areas with reference to relevant indicators.The algorithm search space is obtained by using GIS analysis,and the more livable natural environment area is found in the space by using genetic algorithm(GA).The performance of the algorithm and the selection results are evaluated.The specific research contents are as follows:(1)This paper analyzes the influence factors involved in the natural environment suitability model of human settlements in mountainous rural area,and analyzes the influence of terrain,climate,hydrology,ground cover and other conditions on human settlements environment in combination with data availability.The natural factors are calculated quantitatively,and the suitability evaluation model of natural environment for human settlements in mountainous rural area is constructed.The weights of factors are determined by analytic hierarchy process.Through GIS analysis,the suitability distribution of human settlement natural environment in mountain area was obtained.(2)In this paper,the spatial analysis results of natural environment for human settlement suitability in mountainous rural area are taken as the search space of genetic algorithm(GA).The spatial data are coded by binary coding method and set objective function.The initial population is selected by random method.The fitness of individuals in the population is calculated to carry out the operation of selection,crossover and mutation.After several iterations,the optimal regional distribution of human settlements in mountain rural area is obtained.(3)Combined with the characteristics of natural environment in Yuanyang County,the application analysis of the model was carried out,and the grid map of suitability evaluation of natural environment for human settlement in Yuanyang County was obtained.The grid map is used as the search space of the algorithm,and the best suitable area of natural environment for human settlement in Yuanyang County is selected by genetic algorithm.By comparing the selection results with the beautiful natural villages published by the state.It is found that the areas with the best natural environment can be selected by using genetic algorithm in the whole areas,and most of the beautiful natural villages published by the state can be selected,which indicates that Yuanyang County follows the principle of selecting areas with superior natural environment conditions for development.At the same time,it shows that the combination of GIS and genetic algorithm(GA)is feasible in the selection of natural environment suitable areas for human settlements in mountainous rural,and the results are credible.