Matakuliah
Tahun
Versi
: T0234 / Sistem Informasi Geografis
: 2005
: 01/revisi 1
Pertemuan 06
Fungsi Analisis pada SIG
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan
mahasiswa akan mampu :
• Menunjukkan fungsi-fungsi analisis dari
suatu pemodelan dengan SIG (C3, TIK06)
2
Outline Materi
• Materi 1 : Jenis Fungsi Analisis
• Materi 2 : Pengukuran dalam SIG
• Materi 3 : Perbedaan analisis data Raster
dan Vektor
• Materi 4 : Permasalahan dalam analisis data
3
Jenis Fungsi Analisis (1)
•
•
•
•
•
•
•
Reclassification
Buffering
Neighborhood
Integrating data-Map Overlay
Spatial Interpolation
Analysis of Surfaces
Network Analysis
4
Jenis Fungsi Analisis (2)
Reclassification :
• Usually to produce a new simple code image from a
complex original image, is a very useful technique to be
used in further analysis.
Original class
1. Forest
Reclassification
2. Paddy field
3. …….
1. Green Area….
4. Housing
5. ………
2. Red Area…..
5
Jenis Fungsi Analisis (3)
Buffering :
• Is used to identify a zone of interest around an entity or set
of entities. Buffer zones around :
Points
Line
Area
6
Jenis Fungsi Analisis (4)
Neighborhood :
• The values of individual
cells are altered on the
basis of adjacency
E.q. : Filtering, will change
the value of a cell
based on the attributes
of neighboring cells.
Applying 3x3 square filter
to recalculate value for
cell c4 (in the right)
6
3
3
2
1
2
2
5
3
3
2
1
1
2
4
3
2
2
2
1
1
3
2
2
2
1
1
1
2
1
2
1
1
1
1
1
1
2
1
0
0
0
a
b
c
d
e
f
Minimum Filter c4 = 1
Maximum Filter c4 = 3
Mean Filter
c4 = 1.89
Modal Filter
c4 = 2 (most frequently occurring class)
Diversity Filter c4 = 3 (number of different classes : 1,2,3)
7
Jenis Fungsi Analisis (5)
Integrating data-Map Overlay :
•



•




Vector Overlay
Point in Polygon
Line in Polygon
Polygon on Polygon
Raster Overlay
Point in Polygon (using add)
Line in Polygon (using add)
Polygon on polygon (using add)
Polygon on polygon (Boolean alternative)
8
Jenis Fungsi Analisis (6)
Spatial Interpolation :
•
•
•
•
Local or Global
Exact or approximate
Gradual or Abrupt
Deterministic or stochastic
Analysis of Surfaces :
• Calculating Slope & Aspect
• Visibility Analysis
9
Jenis Fungsi Analisis (7)
Network Analysis :
• Location-allocation Model
• Route Tracing
• Quantitative Spatial Analysis
– Exploratory & Descriptive Statistics
– Predictive Statistics
– Prescriptive Statistics
10
Pengukuran dalam SIG
• Pengukuran Raster
– Length
• Pythagorean Distance
• Manhattan Distance
• Proximity Distance
– Perimeter
– Area
• Pengukuran Vector
– Distance
– Area
11
Analisis data Raster & Vektor
Perbedaan analisis data Raster dan Vektor :
- Users need to be aware of the strengths &
weakness of different type of GIS (raster & vector).
- Have limitations of some of the functions they
routinely apply (e.q. length measurements).
- GIS analyst should be able to produce useful
answers by combining data analysis functions into
an analysis scheme.
- New analysis tools frequently start out in the
academic domain
12
Permasalahan dalam analisis data
Permasalahan dalam vector & raster overlay :
1.
2.
3.
4.
The modifiable areal unit problem.
Ecological fallacy
Selecting threshold criteria
Visual complexity
13
Penutup
• Mahasiswa diharapkan telah mampu
menunjukkan fungsi-fungsi analisis dari
suatu pemodelan dengan SIG.
14