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The continual growth of large and complex databases necessitates the need for more simplified access to the data. Databases have become a key component in managing the voluminous amount of data gathered by different organizations. However, searching and analyzing this data can become time consuming and complicated.
The choice of a GIS data model is an important step in order to integrate large volumes of different data. A data model named Core Data Model of Nepal was designed for IKM/MENRIS ICIMOD as a means to integrate all the themes and provide the user with the ability to organize, update and display spatial, and attribute data according to the thematic domain. The domains are Administrative, Environment, Infrastructure, Hydrography and Topography.
For the past years since its inception, MENRIS/ICIMOD has been developing an integrated Geographic Information Systems (GIS). All these databases were developed using mainly Arc/Info environment. Existing structure of the databases will be a big obstacle to the development of the multidisciplinary projects. Because of this situation an attempt has been made to update the database design and migrate the existing features and attributes from coverage, and shape file format to geodatabase format and to develop an integrated GIS data model to cope with the up to date technology. Whereas coverages maintained graphic features and attributes in separate but related files, geodatabase maintain graphic features and attributes in a true relational database management system (RDBMS) such as an Oracle or SQL Server database.
Core data (vector, raster data) of Nepal is stored in ArcSDE. ArcSDE is an application server that facilitates storing and managing spatial data (raster, vector, and survey) in a DBMS and makes the data available to many kinds of applications. Another advantage of storing data in ArcSDE is that it supports long transaction editing as well as modeling “what if” scenarios by creating versions. Versioning lets users create multiple, persistent representations of the database without making copies of the data. More than one user can modify the same data. At the end of an editing session, edited features are merged into a target version and conflicts are reconciled.
MENRIS Metadata Editor is developed to enable users to create, edit or view GIS metadata without having to use any standard GIS software. This is a further development of MENRIS Metadata Viewer, created earlier, which had only metadata viewing capability. This editor can read ArcView shapefile and extract its extent information and also extract projection information from the projection (.prj) file. The metadata created by using this editor will be ISO 19115 compliant.
ImageSearch: Spatial Search on ImageCatalog database With this ImageSearch application, the users can do spatial search for metadata of satellite imageries in the ImageCatalog database. This application is developed using MapObjects and Visual Basic with basic zoom and pan functions. It also communicates with ImageCatalog database (stored in MS Access file) using Dynamic Data Exchange (DDE). In this application, when the users selects an area of interest on the HKH administrative map, the application searches for imageries belonging to that area of interest in the ImageCatalog database and shows the result in MS Access.
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