Final exam Flashcards
(40 cards)
What the GIS
GIS (Geographic Information System) stores and processes geographic data to support decisions.
DEFINITION OF A GIS
GIS is a system of hardware, software, and data for handling geographic information (ESRI).
Different between GEOGRAPHIC VS GEOSPATIAL
Geographic relates to Earth coordinates; spatial is broader, covering any coordinate system. The terms are often used interchangeably.
Map and 3kinds
Maps use symbols to show location, attributes, and relationships of geographic features.
Different types of map Topographic and Thematic
Topographic map shows Earth’s surface features and landmarks;
Thematic map focuses on specific data like population or climate
Different between Scale and Resolution
Scale is the map-to-ground distance ratio;
Resolution is the smallest feature size that can be represented in digital data.
Cartographic Abstraction:
Choose, group, simplify, exaggerate, and symbolize real-world features for a map
What the GIS WORKFLOW
Real World
Data Sources
Users
Data Management
Analysis
BASIC FUNCTIONS OF A GIS
Data input,
Data storage and management
Processing
Visualization
Output
Decision Support
COMPONENTS OF A GIS
Data
■ People
■ Methods
■ Hardware
■ Software
What the data أنواعها
Spatial data
■ Non-spatial data
■ Data relationships
■ Temporal data
Metadata (data about data
Different between Attributes and spatial data
Attribute Data: Describes characteristics of spatial features (e.g., census, land records).
Spatial Data: Defines location of features (e.g., coordinates, addresses).
HOW DOES A GIS WORK?
STEP 1
Data Collection
Data Assembly
STEP 2 Data Analysis
STEP 3
Data Integration
Data Display
Three key GIS functions:
Querying, modeling, and visualizing data—all rely on spatial databases.
Data Storage Methods:
• Files: Simple, no structure or relationships
• Databases: Structured, managed by a DBMS
FILE STRUCTURES
There are various ways to store
records in a file:
■ Sequential structure or a simple list
To add a new record in a file, simply append it at the end.
Ordered File:
Records are placed by a key (e.g., name or number), not just at the end.
DBMS database
DBMS: Software for storing, managing, and retrieving data from a.
ADVANTAGES OF DATABASES OVER FILES
Data integrity and security
Reduce data maintenance costs
Data independence and efficient access
Better data sharing
WHAT IS A SPATIAL DBMS (SDBMS)
can work with an underlying DBMS
supports spatial indexing
supports spatial data models,
supports spatial operations
HOW IS A SDBMS DIFFERENT FROM A
GIS? spatial analysis
functions such as:
Search:
● Location analysis:
● Terrain analysis:
● Flow analysis:
● Distribution:
● Spatial analysis/Statistics
Data Independence:
Structural Independence:
Data Independence: Change data without changing the DBMS.
Structural Independence: Change structure without affecting data access.
THE NETWORK DATABASE MODEL
- Designed for complex relationships
- Has owners and members structure
- Supports many-to-many (M:N) relationships
What THE HIERARCHICAL DATABASE MODEL
The tree has a root & levels.
• A node is a record.
• A branch is a relationship
