Geography Reference
In-Depth Information
Goodness-of-fit
Criteria
S. No.
Equation
SSE
r
2
; Where,
1
(
SSR
SSE
)
Coefficient of
Determination
(r
2
)
(Draper and
Smith, 1998)
n
2
SSE
z
(
x
)
z
x
)
i
i
7
i
1
n
2
and
SSR
SSE
z
(
x
)
z
(
x
)
i
i
i
1
z
(
x
)
z
(
x
)
Where,
= mean of
.
i
i
Figure 5. Inverse distance weights for relative distance of point to output point.
5.3. Statistical Measures in Spatial Context
Availability of multiple observations of water quality attributes both at
spatial and temporal scales provides an opportunity for exploring spatial and
temporal variations of the water quality in an area. Spatial statistics of the
water quality database (mean, median, standard deviation, coefficient of
variation, etc.) can be easily computed in GIS.
For example, if multi-year and multi-site water quality parameters are
available for a given area. Then annual concentration maps for individual
parameters and years can be prepared through spatial interpolation techniques
(described earlier) in GIS framework. Subsequently, mean (C
mean
) annual
