Basic Spatial Analysis Functions in GIS Flashcards
What is Digimap?
− An EDINA service that delivers OS map data to UK Higher Education institutions
− Allows users to view and print maps of any location in GB at a series of pre-defined scales
− Data also available to download for use in GIS
What is MasterMap?
− Allows you to find, select and download Topography and Integrated Transport Network (ITN) data
What is the Topography layer?
− Large-scale topographic database that offers the most detailed mapping available for Great Britain
− Data are stored as a seamless dataset, i.e. there are no artificial breaks, such as tile boundaries
− Data have been cleaned, structured and vectorised
− Topography layer has nine themes representing:
− Administrative boundaries; Buildings; Heritage and antiquities; Land; Rail; Roads, tracks and paths; Structures; Terrain and height; Water
What is the ITN?
− Definitive road network dataset,
all roads in GB along with routing information for driving and navigation purposes
What is Geocoding?
Assigning XY co-ordinates to ‘something’ such that it can be plotted on a map
What is Reverse Geocoding?
the process of back (or reverse) coding of a point location (X, Y) to a readable address or place
What is geofencing?
Zoning of an area. e.g. on iPhones snapchat filters
What is data conversion and GeoConvert?
It is an online matching and conversion tool for geocoding data
What can GeoConvert do?
− Information about Postcodes
− Obtain postcode metadata (deprivation scores, grid-reference co-ordinates, urban/rural indicators, area classifications, etc.)
− Match One Geography to Another
− Obtain details of the geographical relationships (intersections/matches) between zones in different geographies
− Convert Data from One Geography to Another
− Re-sample (convert) data from one geography to another
What are some built in functions that allow for spatial data analysis?
− Measuring lengths, perimeters, areas
− Selection/querying
− Buffering
− Map overlay e.g. counting points in one layer with respect to polygons in another layer
What is Querying?
A request to select features or records from a database. It is often written as a statement or logical expression
How would you query?
− Click on features using the Info tool − Use the Find tool − Select by location (spatial query) − Features in one layer to select features in another − Select by attribute (SQL query)
What is buffering?
− Measured distance outward from a point, line or polygon to produce a circular zone or a corridor around a feature
What are the two types of buffering?
− Point buffer: Single distance or Multiple (concentric ring)
− Line and polygon buffers
− Variable buffers
