Survey Site Selection Based on the Spatial Sampling Theory:A Case Study in Xiamen Island

We often run into the problem of how to distribute sample points in the process of social survey.Traditional spatial sampling theory is primarily used in single-target.However,social survey questionnaires sometimes are multi-objective.And some objectives are attribute data,for example,a survey related to people's age,education and other social information.Therefore,we should make some improvements based on traditional sampling methods to meet current requirements.Depending on the idea of multi-object and spatial variation,we make a multi-objective survey in this study.In order to meet the need of sampling in the questionnaire survey of Xiamen Island's settlement,we use the sandwich spatial sampling model,balancing the cost of sampling and sampling precision.In general,we adopt three methods: simple random sampling,spatial stratified sampling and sandwich spatial sampling.After comparing of those three methods,the results showed that:(1) When prior knowledge is not sufficient,the result by means of simple random sampling is more reasonable.But when there is sufficient prior knowledge,stratified sampling in space can make more representative samples for the sampling,and also can improve the accuracy of sampling.(2) The distribution of sample points of spatial stratified sampling is primarily related to stratification.The higher the stratified level,i.e.the higher the complexity of the regional,the more the number of sample points is.(3) By comparing the results of spatial stratified sampling by integrated factors and by experts,we can see that stratified sampling is directly or indirectly related with the stratifying process,the rationality of the stratifying design affects the rationality of sampling results.So,in the process of spatial stratified sampling,the rationality of stratifying design is very important for the stratified sampling.The objective of this study is to provide a basis for the sampling in the settlement of Xiamen Island,offer a concept of "complexity" to describe the situation of various regions,and suggest several ideas on the establishment of the multi-objective spatial sampling model.