3161 Advanced Analysis

Advanced Analysis in GIS  Network Operation (connectivity)

Advanced Analysis

 Contiguity operation (raster)  Interpolation and proximity operation  Fuzzy Analysis  GIS Analytical Models  Cartographic Algebra  Expert systems  Linear combination  Digital Terrain Models

URP 3161: Geographical Information System

Ahsanul Kabir

Network Operations

Advanced Analysis

Network consists of roads systems, power grids, water supply system, sewerage systems and the like. Network operations are based on:  Continuous, connected networks  Rules for displacements in a network  Definition of units of measure  Accumulations of attributes value due to displacements  Rules for manipulating attributes

URP 3161: Geographical Information System

Ahsanul Kabir

Network Operations 10

9

Advanced Analysis

5

20

 network analysis depends on the existence of topology in the data  every link and every node in the network must have a unique identity, direction, constraints, start and end.  analysis may include the simulation of moving resources – cars, people, liquids, refuse and so on.  resources moved along these lines encounter resistence in the form of speed limits, road network, peak traffic, barriers, one-way streets, weight limits, traffic lights, bus stops, sharp curves etc. URP 3161: Geographical Information System

Ahsanul Kabir

Network Operations

Advanced Analysis

 the network system elements comprise links, barriers, stopping points and centers. Assigning attributes to such elements permits the simulation of realistic situations.  a unit of measure (impedance: time, money, distance) is to employ to evaluate alternatives.  shortest path, optimal allocation of resources are the common application of network analysis  a limit to mention to assign maximum search radius  centers can assign its catchments; several centers can take part in the analysis

URP 3161: Geographical Information System

Ahsanul Kabir

Advanced Analysis

Connectivity operations on raster data 5

4

6

9

5 6

2

4

3

6 3 2

7 4 1 2

 the technique can be used to compute precipitation runoff from a terrain surface (Hydrological Modeling) 

URP 3161: Geographical Information System

Ahsanul Kabir

Interpolation and Proximity Operations

Advanced Analysis

There are many situations in which the available observations are fewer than needed to cover an area satisfactorily. With the use of both interpolation and extrapolation techniques, it is possible to calculate new values for points lying within or outside the applicable data area.

linear

spline Interpolation

URP 3161: Geographical Information System

Ahsanul Kabir

Advanced Analysis

Interpolation and Proximity Operations

linear

spline Extrapolation

The most usual techniques are:  closest point inter/extrapolation  linear inter/extrapolation  spline inter/extrapolation

URP 3161: Geographical Information System

Weighted average IDW Kriging

Ahsanul Kabir

Advanced Analysis

Interpolation and Proximity Operations

URP 3161: Geographical Information System

Ahsanul Kabir

Advanced Analysis URP 3161: Geographical Information System

Ahsanul Kabir

Advanced Analysis URP 3161: Geographical Information System

Ahsanul Kabir