Environmental Engineering Reference
In-Depth Information
Table 2.1
Different interpolations characteristics (modified information based on [ 18 , 19 ])
Method
Principle
Advantages
Disadvantages
Best suited scenario
Schematic
Nearest neighbor (NN) and thiessen polygon
Selection of values at
closest data point
Ease of use
Inaccurate in less densely
sampled scenarios
Densely sampled
environmental data
Triangulated irregular network (TIN)
Set of conterminous with a
mass factor is used to
define the space
Ability to describe the surface at
different levels of resolution
In most cases, required visual
inspection and manual
control of the network
Dense and moderate
distribution of data
points
Polynomial regression (PR)
Fits the variable of interest
to the linear
combination of
regressor variable
Simple model
Model has poor ability to
predict outside the range
of data points
Moderately dense
sampling with
regard to global
variation
Global polynominal interpolation (GPI)
Works by capturing coarse-
scale patterns in the
data, and fitting a
polynomial
Computationally less intensive
Estimation errors increase
exponentially with
increasing complexity
Regions having sparse
data points and
simple data
patterns
Local polynominal interpolation
Similar to GPI, but the
curve is fitted to a local
subset defined by
windows
Can interpolates short range variations
Misses the global trends in data
Well-distributed data
with no
discontinues
Trend surface analysis (TSA)
Separates the data into
regional trends and
local variations
Assists in removal of broader trends
prior to further analysis
Edge effects and multi-co
linearity caused by spatial
autocorrelation
Important local trends
and not so
important global
trends
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