# An Approach for a Spatial Data Attribute Similarity Measure Based on Granular Computing Closeness
## 4 Case Study
### Results Analysis  
Through the calculation of the similarity measure of land use change types based on granular computing closeness proposed in this paper, the similarity matrix of Figure 6 was obtained by calculating of the similarity of land use economic and social indexes in the Guangxi Zhuang Autonomous Region. The abscissa in the figure, from 1 to 22, respectively, represents paddy field, dryland, woodland, shrubwood, open forest land, other woodland, high-coverage grassland, moderate coverage grassland, low-coverage grassland, river and canal, reservoir pit, mudflat, bottom land, urban land, rural residential area, other construction land, sandy land, saline-alkali land, wet land, bare land, bare rock and sea. It can be seen that the similarity coefficient for each land type and itself was 1, and the similarity coefficient was relatively high among types with larger land areas; the similarity coefficient between land types with less land area and other land types was low. The high similarity coefficient indicates that the two types of land use had similar proportions among different levels of different indexes, such as distances from a road being closer or further, GDP being higher or land being cultivated. Due to the variety of land types, the following discussion focuses on the similarity coefficients of paddy fields, forested land and urban land use. Figure 5: Computing framework for the similarity measures of land use change types in Guangxi based on granular computing closeness. Paddy fields refer to cultivated land with a water source guarantee and irrigation facilities that can be irrigated in typical years to grow aquatic crops such as rice and lotus root, and that includes cultivated land for rice and dry crop rotation. Guangxi paddy fields account for more than 75% of Guangxi's cultivated land, and are mainly distributed in the plains, terraces and hilly areas of east and southeast Guangxi, as well as in the west of Guangxi and the mountainous areas of northern Guangxi, especially in the karst mountains. The distribution of paddy fields in Guangxi is uneven and scattered in the valleys of the mountains. The five land types with the largest similarity coefficient to the paddy field land type were dryland, open forest land, woodland, rural residential area and high-coverage grassland; the five land types with the smallest similarity coefficient to the paddy field land type were saline-alkali land, wet land, bare rock, sandy land and bare land. Paddy fields are generally located in agricultural areas, and are generally part of rural settlements outside of towns. Population density, GDP, distance from the road and sea level were all highly similar, and the brightness of night lights in rural areas also showed a high degree of similarity. The paddy fields in Guangxi are mainly planted with rice, and to ensure the irrigated conditions of the paddy fields, especially in hilly areas, they are commonly distributed around the topographic conditions of reservoirs, ponds and rivers. Guangxi paddy fields also have a high degree of similarity with forested land and other wooded land, which are also related to the topographical conditions in Guangxi, and these three types are mainly distributed in low-altitude, low-slope areas. Guangxi paddy fields and low-coverage grassland have a high degree of similarity. Figure 6: Scatter plot of similarity measures of land use types in Guangxi. small similarity coefficient. Low coverage grassland refers to natural grassland with a coverage of 5-20% that is distributed in areas where water is scarce, grass is sparse and conditions are poor for animal husbandry. Low coverage grassland has completely the opposite natural conditions to paddy fields, so the spatial distribution is completely different, resulting in smaller distances between roads, night light values, population density, GDP and other indexes at different levels.