Download Sistem Informasi Geografis

Sistem Informasi Geografis
Manajemen Basis Data dalam SIG
Aurelio Rahmadian
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
Building
Located on
Resides
Parcel
Owned
by
Shelf
Occupant
Upper
Slope
Plateau
Joe Jonesor
Terrace
Owner
Simple Entity –
Relationship
(E-R) Diagram
Entities represented as
rectangles,
relationship as
diamonds and
attributes as ellipses.
Apex Co.
Lower
Deep
Rise
Slope
Ocean
Desain Konseptual
E-R Model
1. Parts of E-R Model:
• Entities;
3. Rules for identifying
entities, relationships,
and attributes:
• A common noun corresponds
• Relationships between entities;
• Attributes of entities or relationships. to an entity type;
• A transitive verb corresponds
2. Types of normal relationships: to a relationship type;
• An adjective corresponds to
• Belonging to;
an attribute type.
• Set and subset relationships;
• Parent-child relationships;
• Component parts of an object.
Desain Konseptual

Each entity and its attribute map into one or more relational
tables.
Area terbangun
Bangunan
Bangunan
Bangunan
Bangunan
Rise

kantor
rumah sakit
sekolah
pertokoan
Koordinat Letak
Luas
Milik
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).
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
An example of metadata tables:
1. Organization Information
Name of Organization
Department
Room/Suite#
Number & Street Name
City
State
Zip Code
Shelf
Phone Number
Fax Number
Upper Plateau
Contact Person
Slope
or
Extension Number Terrace
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
Lower
Deep
Rise
Slope
Ocean
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
Plateau
or
Terrace
Lower
Deep
Rise
Slope
Ocean
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;
Konstuksi 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
1
1
1
1
2
2
1
1
1
2
2
2
2
2
2
1
1
2
1
3
3
3
3
2
3
3
3
3
3
3
3
3
3
3
3
3
Value Attribute Table
Cell Value Real World Entity
1
Lake
2
Wooded
3
Built-up
Konstuksi DB

Vector GIS Data
Vector GIS Data
Vector GIS Polygon Layer
2
1
3
Polygon Attribute Table
Polygon
Numbet
Identity Attribute
1
Lake
2
Wooded
3
Built-up
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 masingmasing 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