Study On The "Double Evaluation" Method Of County-Level Land Space In Southern Tibet ——A Case Study Of Langkazi County

With the rapid development of urbanization,human demand for space has increased.In this context,reasonable control of space and straightening out the core position of the spatial planning system have become the focus of the government.In the development process of spatial planning system,in order to solve the problems such as conflicts between various plans,the work of"multi compliance and integration"is put on the agenda.In recent years,land space has become the cornerstone of human survival and social development and an important carrier of ecological civilization construction.Evaluating the carrying capacity of resources and environment and the suitability of land space development（hereinafter referred to as"double evaluation"）and identifying the development status and development potential has become an important means of land space development.Based on the theories of short board and the relationship between man and land,combined with relevant concepts,this paper constructs the evaluation ideas and methods of"double evaluation"at the county level in southern Tibet,demonstrates the rationality of the methods,makes an empirical analysis with Langkazi County as an example,and constructs the evaluation index system according to local conditions,The12.5m×12.5m grid created by the county vector boundary is used as the evaluation base map,the results are calculated by means of model quantitative evaluation and identification matrix,finally identify the problem of land space conflict,analyze the problem formation mechanism,and put forward the strategy of land space development and protection.Main conclusions:（1）the ideas and methods of County-level Land Spatial Suitability evaluation are constructed,the index system is established according to the index selection principle,considering the availability of index data,the scientific evaluation method is selected,and the suitability evaluation is carried out according to the evaluation idea and the principle of"ecological priority".（2）The ideas and methods of county-level resource and environment carrying scale evaluation are constructed.Under the condition of finding out the natural conditions of the evaluation area,the factors restricting regional resource development are identified.Different regional restrictive factors are considered differently,and then the resource and environment carrying scale evaluation is carried out under the restrictive factors.（3）Combined with the evaluation ideas and methods,this paper takes Langkazi County as an example to make an empirical analysis.In terms of the suitability of land and space development,the important area of ecological protection is 3731.32 km~2 and the extremely important area is 4239.58 km~2.The area of unsuitable area for agricultural production is 3543.24km~2,and the area of suitable area is 188.08 km2.The area of unsuitable area for urban construction is 3430.39 km~2,and the area of suitable area is 300.93 km~2.In terms of the carrying capacity of resources and environment,the carrying capacity of agricultural production is 2248.27hm~2,the carrying capacity of urban construction is about5176.55hm~2,and the carrying capacity of grassland resources is 546951 sheep.（4）Comparing and analyzing the three types of spatial suitability with the data of the third national land survey,we identified the existing cultivated land of 27.49km~2 and urban construction land of 7.9km~2 in the extremely important ecological protection area,and analyzed the problem formation mechanism,which is mainly affected by factors such as nature,transportation,economy and development direction Agriculture and towns put forward three strategies for the development and protection of land and space in Langkazi county.This study clarifies the evaluation ideas of"double evaluation"at the county level,constructs a scientific evaluation method,and obtains complete evaluation results through empirical analysis,which not only provides a theoretical basis for the preparation of land spatial planning in Langkazi County,but also provides a reference for the"double evaluation"in southern Tibet,deepens the purpose and significance of spatial planning,and promotes the construction of multi-dimensional land spatial planning system.