Transcript Современные зарубежные технологии

Module Spatial
Analysis
Overview
Szekesfehervar
Hungary
Kydyr Nazarkulov
Kyrgyz GIS Centre, ACA* GIScience
Geodesy and GeoInformatics Department, KSUCTA
Content
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What is spatial analysis
Examples of spatial analysis
Types of SA
Conclusion
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Definition
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"A set of techniques whose results depend
on the locations of the objects being analyzed"
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Move the object location and result will change
… = location dependent
"A set of techniques requiring access both to the
locations of objects and also to their attributes"
- Both location information and attribute information are
used in spatial analysis
Source: M. Goodchild, 2001
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Extracting new information
Question
Input
data
Spatial analysis
technique/ methods
Information
Spatial analysis
 models, revealing trends and phenomena which
otherwise may be lost
 Controls human intuitions when human eyes
could be misleading
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Example of Spatial Analysis
applications
von Thunen (1783, - 1850) – isolated city-country
1 – Vegetables, fruits
and milk products
2 – firewood
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3
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1
1
City
3 – crop framing
4 - livestock
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Modified conditions
Source: Wikipedia
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Example of Spatial Analysis
applications
(Dr. John Snow (1813 - 1858)
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SA methods/ techniques
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Simple …
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“what is …?” (identification)
“where is …?” (search)
… more complex
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How is object А located to object В?
What will happen if…
What will be the result of intersection A and B?
The best route from A to B?
Which objects are located in X1, X2, ..., Xn?
…
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Simple questions:
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Thematic search/Тематический поиск
Spatial search/Пространственный поиск
What is …? = question starts with location
information
Where is… ? = question starts with attribute
information
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Spatial Query
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Query - task for search in a database that meet
certain conditions, which is formulated in the
query language.
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In the process the query information can be
sorted and processed statistically, that obtained
the mean, standard deviation, sum, and other
data values.
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Spatial query - is formed under the terms of
containing the coordinates.
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Distance Analysis
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Euclidean distance- measuring straight line
distance between objects or positions
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Buffer (classified distance) – discrete zone(s)
with fixed distance from the object
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Overlay
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- Operation of the graphic overlay one layer to
another, resulting in the formation, or a graphic
composition layer is derived.
The result is presented in a new layer
Use Boolean / logical operators, and
cartographic algebra (map algebra).
The layers were combined in a operators such
as AND, OR, negation, ...
Often inherent in the software commands, such
as intersection, union, and
Weight categories are used when the
importance of the different layers.
Mask: absence / presence of characteristics
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Logical operators
A And B
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AND
OR
XOR
NOT
Set A
A Or B
Set B
A XOr B
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Overlay operations are:
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determine the origin point of the polygon;
determine the origin line of a polygon;
determine the origin polygon polygon;
overlay of two polygonal layers;
destruction of similar classes of polygonal boundaries of
the layer with generation of a new layer;
determining lines of intersection of the objects;
join (combine) the objects of the same type;
determine the point of tangency of a linear object, etc.
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Overlay operation “Point in Polygon”
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Overlay: Union
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Overlay: Intersect
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Overlay: Cut
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(Re)Classification
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Goal
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Manual (re)classification
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group attribute data into ranges of
values for simplification
or: change classification scheme
Number of classes and class
limits can be specified manually
Statistical methods for
determining class limits (depend
on measurement scales)
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Equal interval
Natural breaks
Quantile
Standard deviation
Equal area
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Reclassification
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reclassification is analytical operation, which
is generating map layer with definite
conditions.
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Reclassification
Size of objects.
Individual objects
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Reclassification: Aggregation
Aggregation to reorganise data: Qualitative data as well as
quantitative data ranges can be grouped into discrete
classes -> Reclassification
Classified slopes in Degrees
Slopes in
Degrees
Shallow (0° - 5°)
Medium (>5° - 15°)
Steep (>15° - 30°)
Very steep (>30°)
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Network analysis
Group spatial analytical operations aimed at the
study of topological and geometrical properties
of the linear spatial objects that form a network,
the corresponding graphs.
examples:
 the shortest path
 Selection of the optimal route
 Allocation of resources?
(Possible zone)
 The nearest services.
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Cost surface analysis
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How effective (non-Euclidean) distance can be calculated on a
raster? Using the method of "cumulative distance“
Cells assigned a value of costs / difference
"Distance" is regarded as the difference between the values ​of
neighboring cells.
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Terrain analysis
Terrain analysis creates new information such as:
 - Slope
 - Aspect (Direction)
 - Visibility
 - River Catchment
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Interpolation
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Interpolation predicts unknown values ​based on
known values ​located in other locations
Tobler’s Law: Location of nearby points are more
similar values ​than locations situated far away
from each other.
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Literature
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Longley, P.A., Goodchild M.F., Maguire D.J. and Rhind D.W., 2002.
Geographic Infromation Systems and Science.john Wliey&Sons,
Ltd.
Пространственный Анализ С Использованием Дополнительных
Модулей К Настольным Продуктам ArcGIS. ESRI, 2001
http://www.sli.unimelb.edu.au/gisweb/RSAModule/RSA_A_Zo.htm
Представление и обработка пространственных данных в ГИС:
Методические указания для студентов специальности 071903 –
«Геоинформационные системы» / Сост. И.В.Варфоломеев,
А.С.Савельев. Красноярск: КГТУ, 2001, 31с.
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