1. What is GIS?

GIS (Geographic Information System) is a system designed to capture, store,

analyze, manage, and display spatial or geographic data. It integrates hardware,
software, and data to provide tools for mapping, analyzing spatial relationships,
and solving geographic problems.
2. Why is GIS important?
GIS is important because it helps collect, analyze, and show geographic data,
which makes decision-making easier. It is used in areas like city planning,
environmental protection, and emergency management, helping solve problems
and improve planning.
3. What is the difference between Geographic Information Science
(GIScience) and Geographic Information Systems (GIS)?
Geographic Information Science (GIScience) studies the theories and concepts
behind spatial data, while Geographic Information Systems (GIS) focus on the
practical tools and applications for analyzing and visualizing this data.
4. What are the main components of Geographic Information Systems (GIS)?

The main components of GIS are:

1. Hardware: The physical devices used, such as computers, GPS devices,

and servers.
2. Software: Programs that enable data capture, analysis, and visualization,
like ArcGIS or QGIS.
3. Data: Spatial (geographic coordinates) and non-spatial (attributes) data
used for analysis.
4. People: Users and experts who operate and manage GIS applications.
5. Methods: Procedures and techniques for analyzing and processing
geographic data.

5. In which fields can GIS be used? Give two examples.

GIS can be used in various fields, including:

1. Architecture: GIS is used for site selection, landscape design, and

visualizing urban development projects.
2. Construction: It helps in planning infrastructure, analyzing terrain, and
managing construction logistics.
 6. What is spatial data and attribute data?

1. Spatial Data refers to the geographical location and shape of features on

the earth's surface, such as points, lines, and polygons (e.g., rivers, roads,
or land boundaries).
2. Attribute Data refers to the descriptive information related to spatial
data, such as names, numbers, or characteristics (e.g., population of a
region, land use type).

Spatial Data Attribute Data

Point Descriptive (parcel no, owner, etc.)
Line Quantitative (area, parcel, value etc.)
Polygon Qualitative (water, air, soil etc.)

7. What is the difference between them?

Spatial data defines "where" something is located, while attribute data provides
details about "what" is located at that specific place.

8. What are data layers and topology?

Data Layers: In GIS, data layers are different types of information stacked on top
of each other, like roads, rivers, or land use. They can be analyzed separately or
together.

Topology: Topology describes the spatial relationships between features, like

how roads connect or how a river flows. It ensures data integrity by defining
how features relate to each other.

9. What is the implementation steps of the GIS model?

 Data Acquisition: Maps, satellite images, fieldwork.
 Preprocessing: Format conversion, digitizing, edge rectification.
 Data Management: Variable selection, table design, CRUD operations.
 Manipulation and Analysis: Address matching, network analysis, terrain
modeling.
 Product Generation: Creating maps and reports.
10. What are the allied technologies with GIS?

 Surveying  Cartography
 Remote Sensing  DBMS (Database Management Systems)
 Photogrammetry  Desktop Mapping
 GPS (Global Positioning System)  CAD (Computer-Aided Design)
 11. What are the allied disciplines of GIS?

 Geography  Statistics
 Geodesy  Civil Engineering
 Cartography  Anthropology
 Geology  Forestry
 Meteorology  Epidemiology
12. Why study GIS?

Studying GIS helps us understand and work with maps and data about places. It
is useful in many areas like city planning, environmental protection, and
business, and can lead to many job opportunities.

13. Where is GIS being applied?

 Urban Planning: Zoning, land use, and housing development.
 Environmental Science: Monitoring and managing natural resources.
 Healthcare: Tracking diseases and planning health services.
 Transportation: Route planning and traffic management.
 Business: Market analysis, site selection, and logistics.
 Agriculture: Crop management and land use.
 Disaster Management: Emergency response and risk analysis.

14. What do GIS applications do?

GIS applications help create maps, analyze data, and solve problems. They
measure distances, show patterns, and help make decisions in areas like
planning, transportation, and environment.

15. How does GIS differ from related systems?

While DBMS stores data without location information, GIS ties data to specific
places. CAD is used for design and drafting, not spatial analysis, and AM creates
maps but can't analyze multiple data layers like GIS.

16. What are some key terms and definitions in GIS?

 Feature: A single entity that is part of a landscape, such as a building or

road.
 Format: The specific organization of a digital record.
 Fourth Dimension: Refers to time; the first three dimensions determine
location, while the fourth dimension tracks the creation, duration, and
destruction of an object.
 Geocoding: The process of converting analog maps into computer-
readable form, typically through scanning or digitizing.
 Geographic Information Science: Research on issues surrounding GIS
technology and its implementation.
 GUI (Graphical User Interface): The visual tools (windows, menus, icons)
used to interact with a computer.
 Information System: A system that provides answers to queries from a
database.
 Isoline Map: A map with continuous lines joining points of equal value
(e.g., temperature or elevation).
 Land-Cover Map: A map showing the type of surface covering (e.g., forest,
grassland, or cropland).
 Land-Use Map: A map showing human use of land (e.g., agricultural,
residential, or industrial).
 Line Feature: A geographic feature represented by a sequence of locations
forming a line (e.g., a stream).
 Map: A depiction of geographic phenomena, often at a reduced scale,
with symbols geocoded and stored as a data structure.
 Node: A significant point in a map structure, especially those with
topological importance, such as line endpoints.
 Point Feature: A geographic feature recorded as a single point (e.g., a
house).
 Query: A question asked of a database, especially in GIS, to retrieve
specific information.
 Record: A set of attribute values in a database, equivalent to a row in a
table.
 Spatial Data: Data linked to locations in geographic space, typically
displayed on a map.
 Thematic Map: A map focused on displaying a specific theme or spatial
pattern (e.g., population density).
 Topographic Map: A map showing features like elevations and landforms,
often with contour lines.
 Topology: The description of spatial relationships between geographic
features, such as adjacency or proximity.
 Vector: A map data structure using points, nodes, and segments to
represent geographic features.
 17. What is a map projection?

A map projection is the process of converting the curved surface of the Earth
onto a flat map.

18. What are the basic types of map projections in GIS?

cylindrical, conic, azimuthal

19. What is map scale?

Map scale is the ratio of distances on the map to the actual distances on the
ground.

20. What is spatial join?

Spatial join is the process of combining data from different layers based on their
spatial relationships.

21. What is overlay analysis?

Overlay analysis involves layering multiple datasets to analyze the relationships

between them.

22. What are the main models of the Earth?

Sphere, oblate ellipsoid, and geoid.

23. What is datum?

A datum is a reference framework in GIS and mapping that defines the size,
shape, and position of the Earth. It aligns a mathematical model, such as an
ellipsoid, with the Earth's surface to accurately determine locations and
elevations.

24. Which datum is used in Turkey?

WGS84, NAD27, ITRF-96

25. What is UTM?

UTM (Universal Transverse Mercator) is a coordinate system that divides the

Earth into 60 zones, each 6 degrees of longitude wide, for mapping and
navigation.
 26. What is parameters required for projecting a map?

 Latitude of Origin  Scale Factor

 Central Longitude (Meridian)  Units
 Spheroid/Datum  Standard Parallels (for conic projections)
 False Easting and Northing  Zone (for UTM projections)
27. What is Basic properties of geographic features?

 Size  Neighborhood
 Distribution  Shape
 Pattern  Scale
 Contiguity  Orientation
28. What are the main GIS data models?

Raster and vector data models.

29. What is the raster data model?

The raster model represents the real world as a grid of cells (pixels), where each
cell holds a specific attribute value.

30. What are the advantages of the raster data model?

 Simple data structure.
 Easy to overlay and combine layers.
 Compatible with satellite data.
31. What are the disadvantages of the raster data model?
 Requires large storage space.
 Accuracy is limited by cell size (resolution).
 Not suitable for topological analyses.

32. What is the vector data model?

The vector model represents spatial data using points, lines, and polygons.

33. What are the advantages of the vector data model?

Provides high accuracy.

Efficient storage.

Suitable for topological analyses.

34. What are the disadvantages of the vector data model?

Complex data structure.

Less effective for continuous data like elevation or temperature.

35. Why is topology important in GIS?

Topology validates the geometry of spatial data, detects errors, and ensures the
accuracy of spatial analyses.

36. What are the advantages of topological data structures?

Allows automated error detection and correction.

Prevents gaps or overlaps between polygons.

37. What types of databases are used in GIS?

GIS typically uses relational databases (DBMS).

38. What is metadata, and why is it important?

Metadata is data about data, providing information about the dataset's content,
source, and suitability for use.

39. What is a map layer?

A map layer contains data representing a single characteristic of each location
within a geographic area.

40. What does map layer resolution mean?

Resolution refers to the size of cells in raster data, determining the level of
detail represented.

41. Why is raster-to-vector conversion challenging?

Converting raster to vector requires accurately defining boundaries, which can

be complex.

42. What are common raster data formats?

TIF, GIF, JPEG, DEM.
43. What is geocoding in GIS?

Geocoding is the process of converting spatial information into a computer-

readable format.

44. Where can existing map data be found?

 Map libraries.
 State and federal agencies.
 Commercial data suppliers.
 Online sources like the World Wide Web.
45. What is digitizing in GIS?

Digitizing is the process of converting analog map data into digital data by
tracing lines and points.

46. What are common digitizing errors?

Errors include slivers, duplicate lines or nodes, unended lines, gaps, and zingers.

47. What is scanning in GIS?

Scanning is an automated method of capturing spatial data by creating a raster

image of a map.

48. How does GPS determine location?

GPS uses signals from at least four satellites to calculate latitude, longitude,
elevation, and time differences.

49. What is differential GPS?

Differential GPS improves accuracy by using a stationary receiver to measure

and correct timing errors.

50. What is attribute data in GIS?

Attribute data describes properties of spatial features, such as road type, traffic
volume, or surface material.

51. How is attribute data organized?

Attribute data is typically stored in tables, with rows representing features and
columns representing attributes.

52. What is a data dictionary?

A data dictionary is a catalog of attributes in a database, including their types,

ranges, and valid values.

53. What is the role of a database management system (DBMS) in GIS?

A DBMS stores, retrieves, and validates GIS data using defined constraints and
dictionaries.

54. Why is understanding error important in GIS?

Errors in data can affect all GIS operations, especially when comparing maps or
analyzing across scales.

55. What are common sources of error in GIS?

Errors often arise from geocoding methods, data collection processes, and scale
generalizations.

56. What are the six critical functions of a GIS?

Data capture, storage, management, retrieval, analysis, and visualization.

57. What are the two primary GIS data structures?

Raster (grid-based) and vector (coordinate-based).

58. When is raster data structure preferred?

Raster is preferred for general data like remote sensing, terrain analysis, and
forestry.

59. Why is vector data preferred for precise applications?

It maintains high precision and works well with boundaries, land parcels, and
networks.

60. What is the purpose of topological cleaning?

It eliminates duplicate lines, gaps, and slivers to ensure spatial accuracy.

 61. What are the key factors to consider when selecting a GIS?

Cost, training needs, ease of installation, maintenance support, and user-

friendliness.

62. What is line generalization?

Simplifying lines to reduce detail while maintaining their general shape.

63. Why is topological cleaning important in GIS?

It ensures error-free maps by eliminating slivers, closing gaps, and maintaining

proper topology.

64. What is types of GIS analysis ?

 Spatial Analysis: Examines spatial relationships (e.g., buffers, overlays).
 Attribute Analysis: Queries non-spatial data (e.g., filtering by attributes).
 Overlay Analysis: Combines layers to find intersections or unions.
 Network Analysis: Analyzes connected features (e.g., shortest path).
 Surface Analysis: Works with continuous data (e.g., slope, elevation).
 Proximity Analysis: Measures distance (e.g., buffers, nearest neighbors).
 Temporal Analysis: Studies changes over time (e.g., urban growth).
 Statistical Analysis: Identifies patterns and trends (e.g., clustering).
 Raster Analysis: Operates on grid-based data (e.g., map algebra).
 Geostatistical Analysis: Predicts spatial patterns (e.g., interpolation).
 3D Analysis: Models terrains or features in three dimensions.