“Vector data consists of points, lines and polygons representing geographic features in the real world. QGIS can read and write different types of vector formats.”
QGIS uses the library called GDAL to read and write various formats. In order to do analysis and make maps in a GIS, we need to have data. There are many techniques for creating GIS data. The most common methods are digitizing, importing GPS data, and converting spreadsheet data with latitude and longitude. Once the data has been generated it can then be used in a GIS software and in this module, we will explore the various methods available for loading vector data.
Goal: To explore how to load vector data
Vector layers are differentiated by their type which are points, lines, and polygons. Points contain only a single coordinate pair. Points are typically used to model singular, discrete features such as buildings, wells, power poles and sample locations. Points have only the property of location. Lines are composed of multiple, explicitly connected points. Lines are used to representing linear features such as roads, streams, faults, boundaries, and so forth. Lines have the property of length. Polygons are created by multiple lines that loop back to create a “closed” feature. For polygons, the first coordinate pair (point) on the first line segment is the same as the last coordinate pair on the last line segment. Polygons are used to represent features such as city boundaries, geologic formations, lakes, soil associations, vegetation communities, and so forth. Polygons have the properties of area and perimeter.
There are various ways to load the data into QGIS but the most efficient is the browser as it automatically filters for the correct type to load into QGIS.
Click here to download the sample data for the lesson.