Lec_12_Intro to Geodatabase and Topology

26
Introduction to Geo-database and Topology Prof. Dr. Sajid Rashid Ahmad [email protected] Atiqa Ijaz Khan _ Demonstrator [email protected]

Transcript of Lec_12_Intro to Geodatabase and Topology

Introduction to Geo-database and Topology

Prof. Dr. Sajid Rashid Ahmad

[email protected]

Atiqa Ijaz Khan _ Demonstrator

[email protected]

GEO-DATABASE

Monday, March 30, 2015Institute of Geology, University of the Punjab

2

Geo-Database

• “A database or file structure used primarily to store, query, and manipulate spatialdata. Geo-databases store geometry, spatial reference system, attributes, andbehavioral rules for data.”

• A geo-database contains datasets represents collections of information with a realworld interpretation.

Monday, March 30, 2015Institute of Geology, University of the Punjab

3

History

• In the beginning, there is NO link between Spatial and Non-spatial data.

• 1st Generation:

• Then, both get linked, but stored in separate files.

• 2nd Generation:

• Finally, the spatial and non-spatial datasets are stored in Same table/folder.

Monday, March 30, 2015Institute of Geology, University of the Punjab

4

Monday, March 30, 2015Institute of Geology, University of the Punjab

5

Geo-Database In ArcGIS

• An ArcGIS geo-database is a collection of geographic datasets of varioustypes held in a common file system folder.

• It is a native data structure, used to edit and manage the data.

• It maintain the integrity of the spatial data.

• It store comprehensive information related with each other through objects,feature classes, feature datasets, etc.

• It is a container used to store information.

• It has easy access and management options.

• Users can apply sophisticated rules and operations to data through it.

• It supports multi-user editing.

Monday, March 30, 2015Institute of Geology, University of the Punjab

6

Why to Use it: Benefits

• It is more robust (strong) and extendable than shapefile.

• It make use full capabilities of ArcGIS.

• Support multi-user editing.

• Faster and efficient.

• Manage large datasets easily.

• Use to edit topology.

• Non-spatial data is stored in standard format. Like DBMS (DataBaseManagement System)

Monday, March 30, 2015Institute of Geology, University of the Punjab

7

Types of Geo-Database

• There are 2 major types:

• Single-user Geo-database:

• Personal

• File

• Multi-user Geo-database:

• Enterprise

Monday, March 30, 2015Institute of Geology, University of the Punjab

8

Geo-Database

Single user

File

Personal

Multi-user

Enterprise

Monday, March 30, 2015Institute of Geology, University of the Punjab

9

Monday, March 30, 2015Institute of Geology, University of the Punjab

10Key Properties Personal File

Description Original data format for

ArcGIS geo-databases

stored and managed in

Microsoft Access data files

A collection of various types

of GIS datasets held in a

file system folder

Number of Users Single user and small

workgroups with smaller

datasets

Single user and small

workgroups:

Storage Capacity 1TB-256TB 2GB

Supported Platforms Supported by Widows Supported by Cross-

platforms

Security Operating Windows

Data Type Supported by Geo-database

• The data types supported by geo-database are:

• Shapefile

• Computer Aided Drafting (CAD)

• Triangular Irregular Networks (TIN)

• Grids

• Imagery

• Attribute tables

• Raster Data

• Grids

• GPS coordinates

• Survey measurements, etc.

Monday, March 30, 2015Institute of Geology, University of the Punjab

11

Monday, March 30, 2015Institute of Geology, University of the Punjab

12

Fundamental Datasets in Geo-database

• There are 3 major types of datasets, that are supported by Arc Geo-database:

• Feature Class

• Raster Datasets

• Tables

• These are said to be the structure of geo-database.

Monday, March 30, 2015Institute of Geology, University of the Punjab

13

Monday, March 30, 2015Institute of Geology, University of the Punjab

14

1. Feature is an instant of a feature class.2. It is Spatial Object.3. Use to organize theme related feature class.

Feature Class

Monday, March 30, 2015Institute of Geology, University of the Punjab

15

1. It contains objects having same spatial references.2. It is a collection a feature class.

Feature Data-sets

Monday, March 30, 2015Institute of Geology, University of the Punjab

16

TOPOLOGY

Monday, March 30, 2015Institute of Geology, University of the Punjab

17

Topology

• “A branch of mathematics that deals with the properties of a figure that remainsunchanged ever when the figure is bent, stretched, or otherwise distorted.”

• “In geo-databases, topology is the arrangement that defines how point, line, andpolygon features share coincident geometry.”

Monday, March 30, 2015Institute of Geology, University of the Punjab

18

Types of Topology

Topology

Map Topology

Geo-database Topology

Monday, March 30, 2015Institute of Geology, University of the Punjab

19

Map Topology

• “A temporary set of topological relationships between coincident parts simplefeatures on a map, used to edit shared parts of multiple features.”

• Allows user to edit on scree, by adjusting edges (lines), nodes (end points oflines), etc.

• Can be applied to shapefile and feature class.

• It does not use topology rules.

• Provides with limited version of topology.

• Available at Topology toolbar.

Monday, March 30, 2015Institute of Geology, University of the Punjab

20

Geo-database Topology

• “Geo-database topology defines the spatial relationships of data that all featureclasses must be in the same feature datasets”

• It can only be created for vectors, not for raster.

• It stores errors, exceptions etc.

• It has more extensive rules of topology.

• It can manage and fix the topological errors.

Monday, March 30, 2015Institute of Geology, University of the Punjab

21

Topological Convention

• A topology can reference one or more feature classes from the same featuredataset.

• A feature dataset can have more than one topology.

• However, a feature class can only belong to one topology.

• A feature class cannot belong to a topology and a geometric network.

Monday, March 30, 2015Institute of Geology, University of the Punjab

22

Topology Rules

• “A group of instruction to the geo-database defining the permissible relationshipsof features within a given feature class or between features in two different featureclasses.”

• Different types of rules are available for different types of spatial relationships.

• Some rules are for within a feature class.

• Some rules are for between two feature classes.

• There are 26 rules available in ArcGIS Topology, having 3 divisions:

• Polygon Rules

• Line Rules

• Point Rules

Monday, March 30, 2015Institute of Geology, University of the Punjab

23

Monday, March 30, 2015Institute of Geology, University of the Punjab

24

Download the Rules Poster: Link

http://www.google.com.pk/imgres?imgurl=https://apollomapping.com/wp-content/user_uploads/2014/05/topology_rules_poster-

300x234.jpg&imgrefurl=https://apollomapping.com/blog/g-faq-spatial-topology-gis-part&h=234&w=300&tbnid=whDwfYDh4DhTtM:&zoom=1&docid=Lak_ZoGKneoPr

M&ei=7Z8VVdyCFI3uatHbgqgO&tbm=isch&ved=0CCYQMygNMA0

Monday, March 30, 2015Institute of Geology, University of the Punjab

25

Monday, March 30, 2015Institute of Geology, University of the Punjab

26