REVEALING SPATIAL PATTERNS THROUGH SPATIAL DATA MINING AND VISUAL EXPLORATION IN TEMPORAL DATA
A. Torun1, S. Duzgun2
1 - General Command of Mapping, Cartography Dept., Ankara, Turkey
2 - Middle East tech Univ., GGIT Dept, Ankara, Turkey
Spatial databases reside terabytes of spatial data that may be obtained from topographic maps, aerial photos, satellite images, medical equipments, laser/lidar scanners, video cameras among others in public and private organizations which also access several databases comprising census, economic, security, and statistical information for enterprise business processes. It is costly and often unrealistic for users to examine spatial data in detail and search for meaningful patterns or relationships among data. Spatial data mining (SDM) aims to automate such a knowledge discovery process in large databases along with visual exploration techniques.
Data on its own has no value. Without exploration techniques, it is possible to end up with massive amounts of data but no information. SDM plays an important role in; extracting interesting spatial patterns and features, capturing intrinsic relationships among spatial data. Being preliminary data mining stage, exploratory techniques allow investigating first and second order effects of the data.
Cartographic visualization allows user to interact with huge spatial datasets to recognize spatial distributions and, relationships and extract meaningful information by facilitating comparison, conceptualizing spatial patterns and processes, and other cognitive skills by making use of the visualization enabled system. Cartographic visualization is the most effective way of communicating information about the location and spatial characteristics of the natural world and of society. Moreover, easy to use spatial exploration and decision making tools integrated in enterprise information systems available for ordinary and non-spatio-experts introduced in daily life and enterprise business workflow.
In the development stage, GIS and GI Technology shaped their strategy due to the needs of powerful customers such as governmental, administrative and research organizations. Individualism, change of individual demands forces the sector to consider how people best understand spatial phenomena, how humans actually perceive and process spatial information, and how this varies among individuals and across cultures. This new trend opens a new perspective and era for cartographic/geographic visualization being a mature visual communication methodology for centuries. From a practical point of view, visual exploration techniques are becoming a kind of common “language” within an enterprise GIS across organizational boundaries.
In this study, firstly, spatial data mining and visual exploration techniques are introduced. Then, an application is implemented on historical data of oil transportation and ship accidents at Istanbul Bogazi to discover spatial patterns among the data and its environment. Within the context of paper, experiences in data preparation, data organization, drawbacks of handling historical data are given.