By analyzing the fundamental spatiotemporal characteristics of spatiotemporal objects, six query primitives, which are temporal range, spatial range, spatiotemporal range, temporal relation, spatial relation and attribute state, are proposed based on object-oriented snapshot model. Centered on time, atomic queries are defined, and approaches to constructing complex queries from these atomic queries are proposed. On the purpose of rendering the proposed query model more systematic and adaptable, application semantics are not considered in defining query primitives and atomic queries. In addition, owing to its clear expressiveness in GIS, the model possesses considerable implementability and can serve as the foundation and basis of implementations of spatiotemporal query interfaces in temporal GIS.

By analyzing floating taxi trajectory data, and using complex network theories, the complex structural (including topological structural, weight structural and spatial structural) properties of urban taxi passenger flow network is researched. The results indicate that the distances of taxi passenger flow obey a log-normal distribution. Distributions of degree, weight strength and distance strength of nodes indicate power-law decay with a “cut-off”. Weight distribution of edges also fits a power-law distribution quite well. There are strong power-law correlations between degree and both weight strength and distance strength. The assortative mixing of weight strength of nodes shows a slight positive correlation. These results indicate the relationships of topological, weight and spatial structural properties of taxi passenger flow network, and will be beneficial for revealing the interplaying mechanism and principles among urban spatial, functional and population travel characteristics.