Manajemen Basis Data dalam SIG
Sistem Informasi Geografis
Sistem Manajemen Basis Data SIG
SIG merupakan perangkat pengelolaan basis data (DBMS =
Data Base Management System) dimana interaksi dengan
pemakai dilakukan dengan suatu sistem antar muka dan
sistem query dan basis data dibangun untuk aplikasi
multiuser.
SIG merupakan perangkat analisis keruangan (spatial analysis)
dengan kelebihan dapat mengelola data spasial dan data non-
spasial sekaligus.
Sistem Manajemen Basis Data SIG
Syarat pengorganisasian data:
Volum kecil dengan klasifikasi data yang baik;
Penyajian yang akurat;
Mudah dan cepat dalam pencarian kembali (data retrieval) dan penggabungan (proses komposit).
Tipe Data Data lokasi:
Koordinat lokasi
Nama lokasi
Lokasi topologi (letak relatif: sebelah kiri danau A, sebelah kanan pertokoan
B)
Data non-lokasi:
Curah hujan
Jumlah panen padi
Terdiri dari variabel (tanah), kelas (alluvial), nilai luas (10 ha), jenis (pasir)
Data dimensi waktu (temporal):
Data non-lokasi di lokasi bersangkutan dapat berubah dengan waktu (misal:
data curah hujan bulan Desember akan berbeda dengan bulan Juli)
Desain Konseptual
Data Model
A data model is a formal specification for the entities, their
attributes and all relationships between the entities for the GIS.
The purpose of a data model is to make it possible for both user
and GIS analyst agree on the data definitions which is
represented completely rigorous and unambiguous fashion.
Desain Konseptual
Deep Ocean
Shelf
Upper Slope
Rise Lower Slope
Plateau or Terrace
Building Located on Parcel
Resides Owned
by
Occupant Joe Jones Owner Apex Co.
Simple Entity – Relationship (E-R) Diagram
Entities represented as rectangles, relationship as diamonds and attributes as ellipses.
Desain Konseptual
E-R Model
• Entities;
• Relationships between entities;
• Attributes of entities or relationships.
• Belonging to;
• Set and subset relationships;
• Parent-child relationships;
• Component parts of an object.
1. Parts of E-R Model:
2. Types of normal relationships:
3. Rules for identifying
entities, relationships,
and attributes:
• A common noun corresponds
to an entity type;
• A transitive verb corresponds
to a relationship type;
• An adjective corresponds to
an attribute type.
Desain Konseptual Each entity and its attribute map into one or more relational
tables.
Each relationship is a regular relationship executed by the relational database query system or a spatial relationship and if it is not a standard operation then the indicated operation which usually includes a complex computation need to be written (using Avenue Script/Macro Language).
Rise
Area terbangun Bangunan kantor
Bangunan rumah sakit
Bangunan sekolah
Bangunan pertokoan
Koordinat Letak
Luas
Milik
Desain Konseptual Metadata is “information about data”: (i) describe the characteristics of the data (entity
and attributes) using its standard name, and (ii) provide information on its accuracy and
its source and its archiving provision.
Important functions of metadata: provide (i) a basic data description of a data set; (ii)
information for data transfer / sharing; (iii) information for entries into clearinghouses
to catalogue the availability of data.
Metadata should serve as: (i) a documentation and data management tool; (ii) data
definition, source documentation, management and updating, data archiving and
retention requirement; (iii) information to support database description for spatial data
clearinghouses.
Desain Konseptual
Deep Ocean
Shelf
Upper Slope
Rise Lower Slope
Plateau or Terrace
An example of metadata tables:
1. Organization Information
Name of Organization
Department
Room/Suite#
Number & Street Name
City
State
Zip Code
Phone Number
Fax Number
Contact Person
Extension Number
E-mail Address
Internet Address
Comments
2. Reference Information
Filename
File Format
Availability
Cost
File Internet Address
Metadata Created By
Date Metada Created
Metadata Updated By
Date Metadata Updated
Metadata Standard Name
Comments
5. Attribute Information
Data Object Name
Data Attribute Name
Attribute Description
Attribute Filename
Code Set Name
Code Set Description
Measurement units
Accuracy Description
Comments
Perencanaan DB
The quality of information
Information is stored in a database;
Bad construction and data error will give Garbage instead of
Geographic Information System;
What kind of map projection will be used;
What scale is the data;
What is the coverage;
How much attribution should be included;
What is the attribute data format;
What is the data reliability;
How fast is it to be retrieved.
Perencanaan DB Information required for database design:
A complete list of data, properly defined and checked for
validity and consistency (from the master data list, E-R data model, and metadata entries);
A list of potential data source (maps, aerial photos, tabular
files, digital files) cataloged and evaluated for accuracy and completeness (from available data survey);
The list of functional capabilities required from the GIS
(from needs assessment). Such as visualization, spatial analysis, statistical analysis and modeling.
Perencanaan DB
Entities,
Attributes, and
Spatial Object
Deep Ocean Rise
Lower Slope
Plateau or Terrace
Perencanaan DB
Plan for data sharing
Benefits of data sharing include: (i) the development of much
larger database for far less cost; (ii) the development of more
efficient interaction between public agencies; and (iii) all
agencies shared the same up-to-date database / information.
Database maintenance requires two efforts: ongoing user
training (how to maintain the database) and user support (who
will be responsible for updating which data).
Perencanaan DB
Designing the Database
Most of databases in GIS software packages are based on the
relational database model;
Two choices of using data table: as much data in one table or
small/compact data in one table;
How you will represent the data: point, line, polygon, network,
etc.
Konstruksi DB
Database construction/conversion is the process of building
the digital database from the source data - maps and tabular
files.
The main emphasis is management of the activity and quality
assurance / quality control of the converted data.
Konstruksi DB
Data Conversion
Manual digitizing using a digitizing tablet and cursor tool
(puck);
Scanning (converts lines and text into series of pixels);
Raster to Vector Conversion (convert series of pixels into series
of (x,y) coordinates points), this facility is usually provided by a
GIS software;
Hybrid solution (overlaying vector format data with an image
provides a powerful graphic display tool;
Konstruksi DB • Map graphics represent all of the features (entities) on a map as
points, lines, areas, or pixels;
• Tabular databases contain the attribute information which describe the entities (building, parcel, etc.);
• A common key (graphics data index) must be established between the map graphics and the tabular database records to create a link.
Graphics Data Index
Konstuksi DB
Raster Data (pixels)
Raster GIS Data
Graphics Grid / Raster Value Attribute Table
1 1 1 1 2 2
1 1 1 2 2 2
1 1 2 2 2 2
1 3 3 3 3 2
3 3 3 3 3 3
3 3 3 3 3 3
Cell Value Real World Entity
1 Lake
2 Wooded
3 Built-up
Konstuksi DB
Vector GIS Data
Vector GIS Data
Vector GIS Polygon Layer Polygon Attribute Table
Polygon Identity Attribute
Numbet
1 Lake
2 Wooded
3 Built-up
1 2
3
Basis Data Relasional
Basis Data relasional menggunakan tabel dua
dimensi yang terdiri atas baris dan kolom untuk
memberi gambaran sebuah berkas data.
Basis Data Relasional
MHS
NPM
Nama
Alamat
10296832
Nurhayati
Jakarta
10296126
Astuti
Jakarta
31296500
Budi
Depok
41296525
Prananingrum
Bogor
50096487
Pipit
Bekasi
21196353
Quraish
Bogor
Basis Data Relasional
MKUL
KDMK
MTKULIAH
SKS
KK021
P. Basis Data
2
KD132
SIM
3
KU122
Pancasila
2
Basis Data Relasional
NILAI
NPM
KDMK
MID
FINAL
10296832
KK021
60
75
10296126
KD132
70
90
31296500
KK021
55
40
41296525
KU122
90
80
21196353
KU122
75
75
50095487
KD132
80
0
10296832
KD132
40
30
Basis Data Relasional
Keuntungan:
Bentuknya sederhana
Mudah melakukan berbagai operasi data
Basis Data Relasional
Sumber:
Dinar D.A. Putranto,
‘Pendekatan Basisdata
Berorientasi Obyek untuk
Manajemen Tata Ruang Kota’,
Disertasi Doktor, ITB, 2000.
Hybrid & Integrated System Pengertian 1: Struktur data vektor dan struktur data raster dapat dipadukan pada suatu
sistem, dengan melengkapi fasilitas konversi vektor ke raster dan raster ke vektor. Selain itu juga disediakan fungsi-fungsi untuk mengolah masing-masing struktur data
Pengertian 2: Data SIG terdiri dari dua bentuk data: yaitu data grafis yang menyatakan entitas obyek dan data attribut. Data grafis yang terdiri dari data koordinat dan data topologi disimpan di berkas yang terpisah dari data atribut. Data atribut ditangani oleh database management system. Penggabungan kedua tipe data dilakukan melalui suatu kode identifikasi, misal kode identifikasi poligon, garis atau titik. Hal yang sama juga dapat dilakukan „linkage‟ antara grid-cell modules dengan database management system.
Pengertian 3: Operasional SIG secara keseluruhan yang terdiri dari SIG software, CAD software, Image Processing software, GPS software, Open-Source components, DBMS system
Hybrid & Integrated System
Hybrid & Integrated System