Databases
Locating Corrupted Geodatabase Files A corrupted file geodatabase can cause a variety of issues in QGIS, including crashes, missing data, and errors opening or editing data. Here are some tips for locating corrupted geodatabase files: Check the QGIS log file for error messages related to the geodatabase. Errors about corrupt files or inability to open…
Understanding File Geodatabases A file geodatabase is a geographic database stored in a folder system format on disk. Key capabilities offered by file geodatabases include: (1) storing and managing spatial data in a relational database; (2) support for large file and dataset sizes up to 1 TB; (3) advanced spatial indexing for faster read and…
Ensuring Accurate Location Data The geographic location of spatial features in a GIS is critical to enable accurate analysis and visualization. However, location data can easily become inaccurate due to issues with data collection, transformation errors, or lack of quality control. Implementing methods to continually assess, improve, and maintain the accuracy of coordinate data is…
Standardizing Geospatial Data Integrating geospatial data from different sources often requires standardizing the coordinate systems and data formats used. Defining common coordinate systems and map projections allows different datasets to be viewed and analyzed in a common geographic framework. Converting data to use consistent attribute formatting and metadata standards facilitates interoperability and automated analysis workflows….
Gathering Data from Multiple Sources The first step in enriching GIS analysis is identifying and gathering relevant data from a variety of sources. Government agencies at local, regional, and national levels often provide authoritative spatial data relevant to GIS users. Open data portals have proliferated in recent years, offering freely available datasets for download. Commercial…
The Problem of Inconsistent Data Types Comma-separated values (CSV) files often lack defined data types for their attributes. When importing these untyped datasets into GIS systems, the software must guess the appropriate types like strings, integers, and dates. Sometimes the detection fails or assigns inaccurate types to columns. This can create major issues down the…
Storing Massive Geospatial Data As geospatial datasets grow larger in size and complexity, effectively storing, processing, and analyzing the data poses challenges for database administrators and GIS professionals. PostGIS, as a spatial database extender for PostgreSQL, provides advanced capabilities for working with big geospatial data. Overcoming Database Size Limits By default, PostgreSQL databases are limited…
Combining Diverse Geospatial Data Integrating varied geospatial data sources presents challenges due to differences in formats, standards, coordinate systems, data models, accuracy, and precision. Successful integration requires transforming datasets to match coordinate reference systems, conflating data to a common schema, leveraging interoperability standards, utilizing metadata, and employing customized tools and technologies. When thoughtfully combined, heterogeneous…
Overcoming Data Quality Issues in GIS Geographic information systems (GIS) integrate hardware, software, and data to capture, manage, analyze, and display information related to positions on the Earth’s surface. GIS allows users to view, interpret, question, visualize, and understand data in ways that reveal relationships, patterns, and trends. However, for GIS to deliver reliable and…
Understanding Geospatial Data Geospatial data refers to information about geographic locations that are represented by numerical coordinate values. The coordinates pinpoint positions on the Earth’s surface and define the geospatial component of the data. Understanding key properties like coordinate systems, map projections, and metadata provides the foundation for working with geospatial data effectively. Defining Key…
