Suitability Evaluation of County-level Spatial Development under the Support of Geographic National Conditions Information Jiongyu MA and Dongyu REN, China ABSTRACT Suitability assessment for the spatial development is of fundamental importance in the national spatial planning, including protecting the national eco-space, rationally distributing the construction space, optimizing the spatial development pattern, etc. We establish the assessment index system, which is suitable for the spatial development of Pujiang County, by using geographical condition data, large-scale survey data, industrial special data, and industrial statistical data. During data processing, we use the GIS spatial analysis technique by choosing terrain, economic level, population density, and artery traffic as the suitability indexes, meanwhile choosing available land resources, available water resources, natural hazard, ecological vulnerability, and environmental capacity as the constraint indexes. From the aspect of the grid-based spatial scale, we particularly analyze the suitability of spatial development in Pujiang County, which involves four development levels: the most suitable, the more suitable, the less suitable, and the least suitable. Overall, each level of region occupies 4 %, 14 %, 15 %, and 67 %, respectively. The spatial suitability in Pujiang can be summarized as ‘large prohibitive development region and strong eco-system constraint’. Moreover, the suitability development level exhibits time-order character. The newly built district is gradually outward according to current status. The development potential in this County tends to gradually reduce. In contrast to previous assessment mode with the administrative district as a unit, the spatial grid-based method makes a great breakthrough, which elaborately reflects the spatial difference between the development suitability and development constraint. This method offers technical supports for determining resource development intensity and improving the well-organized layout of the national spatial science. Key words Land distribution, Land management, Land readjustment, Spatial planning Suitability Evaluation of County-Level Spatial Development Under the Support of Geographic National Conditions Information (10741) Jiongyu Ma, Dongyu Ren and Xuehu Wen (China, PR) FIG Working Week 2020 Smart surveyors for land and water management Amsterdam, the Netherlands, 10–14 May 2020 Suitability Evaluation of County-level Spatial Development under the Support of Geographic National Conditions Information Jiongyu MA and Dongyu REN, China 1. INTRODUCTION Suitability assessment for the spatial development is the core content of county spatial planning, it is an effective method for solving disorderly expansion of construction land, and rationally distributing national spatial resource[1]. After the 19th National Congress of China, the spatial governance system and ability will become more scientific, systematic and democratic[2]. As an important theoretical and functional basis, the suitability assessment for the spatial development is guided by the concept of green development. In the overall development, the suitability assessment identifies regions with different development needs. Regions with low development costs, large capacity for resource environment and strong development needs to undertake high intensity socioeconomic activities, will be allowed to conduct high intensity development. On the other hand, regions with high ecological value but low development ability will be focused on eco-system maintenance rather than other socioeconomic activities[3-4]. In traditional suitability assessment methods for the spatial development, the evaluation unit is administrative district. But, using administrative district as the evaluation unit will lack the consideration of the actual spatial distribution. Thus, the evaluation result will hardly reflect the spatial development characteristics and details, and seriously affect the guidance value for reginal spatial functional zoning[5]. In recent years, under the support of GIS technology, spatial grids have been gradually applied to various types of research, providing ideas and technical supports[6-8]. The grid utilities equal size square grid to form the basic regional unit, providing different function and policy guidance for different unit and fully express the elemental differences in spatial distribution[9-12]. This paper uses GIS spatial technology and takes Pujiang , Chengdu, China as the research area. Under the same evaluation index, the paper compares and analyzes the differences in the evaluation results of the suitability assessment for spatial development from the perspectives of the administrative district unit and the grid unit to determine a more suitable county range spatial development. 2. STUDY AREA Pujiang is a county that belong to the Chengdu city. Pujiang is in the southwest of Sichuan Suitability Evaluation of County-Level Spatial Development Under the Support of Geographic National Conditions Information (10741) Jiongyu Ma, Dongyu Ren and Xuehu Wen (China, PR) FIG Working Week 2020 Smart surveyors for land and water management Amsterdam, the Netherlands, 10–14 May 2020 Basin and Chengdu Plain, between 103 ° 19 ′ to 103 ° 41 ′ east longitude and 30 ° 05 ′ to 30 ° 20 ′ north latitude. Pujiang is adjacent to Pengshang city and Meishang city on the east side and is surrounded by mountain area on the west side. Pujiang is located at the intersection of Chengdu, Meishan and Ya'an, close to the Tianfu new district which is part of Chengdu's "half an hour Economic Circle". Currently, the main transportation method in Pujiang is by road. There are four main roads, eight county roads, and four coach stations (long distance bus stations). Furthermore, by 2020, the plan for "three railway, two highway and five expressway" will be realized in Pujiang. In 2016, the GDP of Pujiang is 11.797 billion Chinese Yuan (around $1.7 billion USD), a YoY growth of 10.5 percent. The per cap GDP of Pujiang is 46,463 Chinese Yuan (around $6,698.14 USD), a YoY growth of 16.2 percent. The structure of the three-sector (primary industry, secondary industry and tertiary industry) is 15.7:49.8:34.5. The year-end population of Pujiang in 2016 is 268,291 people, where 29.5 percent is urban population and 70.5 percent is rural population. The year-end permanent resident population is 254.1 thousand people, reaches an urbanization rate of 40.51 percent. 3. EVALUATION INDEXES AND RESEARCH METHODS 3.1 Evaluation indexes Suitability assessment for the spatial development applied the territorial function theory and the main function planning theory in assessing the spatial development. In addition, the suitability assessment for the spatial development consider important variables including ecological and environmental conditions, resource bearing and the degree of utilization, economic benefits and development needs of the area to provide more accurate assessment result. Thus, considering the territorial function and the main function planning of Pujiang, the evaluation indexes for the suitability assessment are generated from two aspects, suitability and constraint. The suitability indexes include topography, population, economic level, and impact of traffic arteries. The constraint indexes include available land resources, available water resources, impact of natural hazard and ecological vulnerability. 3.2 Research methods 3.2.1 Data collection and processing This research collects and uses data of Pujiang for the year 2016. The data sources include Development and Reform Bureau, Urban and Rural Planning Bureau, Environmental protection Suitability Evaluation of County-Level Spatial Development Under the Support of Geographic National Conditions Information (10741) Jiongyu Ma, Dongyu Ren and Xuehu Wen (China, PR) FIG Working Week 2020 Smart surveyors for land and water management Amsterdam, the Netherlands, 10–14 May 2020 Bureau, Land and Resources Bureau, Statistics Bureau, Transportation Bureau, and Water Authority. The data from Water Authority include gross product, nature preserve, permanent basic farmland, ecological red line, transport facilities layout, water resources (water resource include agricultural water consumption, industrial water consumption, domestic water consumption). The spatial data mainly includes the results of 2016 National Geographic Situation Monitoring and DEM with 10-meter resolution. In order to facilitate data analysis and calculation, the collected data is preprocessed. All text information is organized into table or text form. All spatial data coordinates are uniformly defined as the CGS2000 coordinate system, Gauss-Kruger projection, and all data are uniformly converted into GDB format for storage. 3.2.2 Multi-index comprehensive evaluation According to the evaluation index system, the entropy weight method[13] is used to determine the index weight. In information theory, information is a measure of the degree of order of a system, and entropy is a measure of the degree of disorder of a system; the smaller the information entropy of an indicator, the more information is provided by that indicator, which means it will have a heavier weight in the assessment. The Entropy weight method as following: 1、Standardize the data Standardize the data of each indicator. Suppose there are k indicators 푋1, 푋2,…, 푋푘，where 푋푖 = {푋1, 푋2, … , 푋푛}, and after standardization the value of the indicators are 푌1, 푌2,…, 푌푘， Then 푌푖푗 = (푥푖푗 − min(푥푖))/(max