data management

Question 1

spatial data?

Answer 1

Spatial data are all the data that can be
localized in a spatial reference system.

Question 2

geographical data?

Answer 2

are all the data that can be semantically identified and localised in a spatial reference system about the earth

Question 3

What is management?

Answer 3

is the process where the resources of an organisation are coordinated and directed in the direction of the accomplishment of commonly decided goals

Question 4

What is GIS?

Answer 4

A geographic information system (GIS) is a framework for gathering, managing, and analyzing data which are spatially referenced to the Earth

Question 5

components of GIS

Answer 5

• Hardware or computer equipment
• Software
• Data
• People
• Methods (business rules)

Question 6

what problems can GIS help to answer?

Answer 6

• Location: The exact position on Earth.
• Patterns: How features are distributed.
• Trends: Changes over time.
• Conditions: Requirements or limits.
• Implications: Potential effects of actions.

Question 7

What are the three components of spatial data?

Answer 7

Temporal (When): the time of an event or data collection.

Thematic (What): the characteristics of the data.

Spatial (Where): the geographic location of the data.

Question 8

What are the two types of spatial coordinate systems?

Answer 8

Geographic Coordinate Systems (GCS): Used to locate objects on the Earth’s surface in 2D or 3D space.

Projected Coordinate Systems (PCS): Used to locate objects on a flat map in 2D; PCS = GCS + map projection.

Question 9

What are the four types of attribute data?

Answer 9

Nominal: Classifies features into groups without order (e.g., cities, countries).

Ordinal: Orders data into ranked categories without exact values.

Interval: Provides values with equal units, allowing distance interpretation.

Ratio: Like interval, but with a true zero,

Question 10

What are the five types of spatial entities in conceptual data modelling?

Answer 10

• Point: Represents a single location (e.g., city, landmark).
• Line: Represents linear features (e.g., roads, rivers).
• Area (Polygon): Represents enclosed areas (e.g., lakes, parks).
• Network: Represents interconnected features (e.g., transportation, utilities).
• Surface: Represents continuous features (e.g., elevation, temperature).

Question 11

What is geodataframe in GeoPandas in Python?

Answer 11

is a data structure that combines the functionality of a Pandas DataFrame with spatial data, allowing you to store tabular data (rows and columns) and geometries (points, lines, or polygons) in one structure.
.

Question 12

What are raster and vector data? What are the common data formats of raster and vector data?

Answer 12

• Raster data: spatial data using a grid of cells ass building blocks to represent features
  -> GEOTIFF, ERDAS
• Vector data is spatial data using cartesian (x,y) coordinates to define the shape of spatial features, the point is the basic building block
  -> GEOJSON, SHAPEFILE

Question 13

What is a layered approach?

Answer 13

involves combining data about different features, with each layer representing a specific type of feature. these layers may use diff data formats, spatial models or coordinate systems, may require transformation to combine them correctly

Question 14

What is a minimum bounding box (MBB)？Why is it useful for spatial indexes?

Answer 14

is the smallest rectangle, aligned with the coordinate axes, that fully encloses a spatial feature or dataset. It is often used in spatial indexing to simplify calculations.

Question 15

What are the common spatial topological relations in PostGIS?

Answer 15

equals, intersects, disjoint, touch, cross, overlap, within, contains

Question 16

What is a buffering? What is an inward buffering? What is an outward buffering? What is a bi-directional bufferring?

Answer 16

• Buffering: creation of a zone of interest around an entity
• inward buffering: buffer zone extension inward from a polygon boundary
• outward buffering: extension outward from a polygon boundary
• bi directional buffering: outward and inward direction

Question 17

What is a map overlay analysis?

Answer 17

Map overlay analysis combines two or more spatial layers to create a new layer, helping to identify connections, or patterns among features

Question 18

What is spatial interpolation? Some existing methods?

Answer 18

process of using points with known values to estimate values at other unknown points

methods:
* linear triangulation
* inverse distance weighted
* kriging

Question 19

What are the classic applications of network analysis?

Answer 19

• Shortest paths: Finding the shortest path between two points on a network.
• Traveling salesperson problem: Finding the shortest route that visits multiple locations and returns to the start.
• Allocation modelling: Allocating resources by modeling supply and demand through a network.
• Route tracing: Tracing the flow of goods, people, services, or information through a network.

Question 20

What is geographic interoperability?

Answer 20

Geographic interoperability is the ability of information systems to exchange spatial data about the Earth and its features, and to collaboratively run software that can manipulate this data over networks.

Question 21

What are WMS, WFS, and WCS? What are the typical operations/functions they offer?

Answer 21

• web map service: produces maps of spatially referenced data dynamically from one or more distributed geospatial databases.
• Web feature service: Provides geographic features to clients and allows them to add or modify features.
• Web coverage service: service that allows access to underlying raster or coverage data.

Question 22

What is metadata? Why is it important for spatial data sharing?

Answer 22

Metadata is “data about data.” it refers to a file that describes basic characteristics of data or resources. Geospatial metadata are used to document geographic digital resources

It is important because it allows users to: Discover and understand the data, Evaluate the quality and correctly use the data

Question 23

What is INSPIRE?

Answer 23

.
is an EU initiative to create a spatial data infrastructure, making geographic information more accessible and interoperable for sustainable development.