Geoscience Reference
In-Depth Information
TABLE 8.4
Evaluation of Sensitivity Analysis and Goodness-of-Fit Statistics for
Estimating Pan Evaporation Using GEP
Model Number
1
2
3
4
5
6
7
8
9
10
Development period goodness-of-fit statistics
R
-squared
0.90
0.85
0.86
0.90
0.88
0.89
0.89
0.90
0.90
0.87
RMSE
1.39
2.97
1.72
1.39
1.64
1.47
1.45
1.45
1.43
1.58
MAE
1.03
2.48
1.32
1.05
1.23
1.11
1.08
1.08
1.09
1.21
ME (bias)
−0.01
−2.36
0.12
0.11
−0.18
0.02
−0.03
−0.17
0.69
0.01
Sensitivity analysis
T
max
(
D
0)
✓
-
×
-
✓
-
✓
✓
×
-
T
min
(
D
1)
✓
✓
×
×
✓
✓
✓
✓
✓
✓
T
avg
(
D
2)
×
-
✓
✓
✓
-
-
✓
-
-
RH
max
(
D
3)
-
-
-
-
-
-
✓
-
-
-
RH
min
(
D
4)
✓
✓
×
×
✓
×
-
✓
✓
×
RH
avg
(
D
5)
-
-
-
-
✓
✓
✓
✓
✓
✓
Rs
(
D
6)
✓
✓
×
×
✓
✓
✓
✓
✓
✓
U
(
D
7)
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Test period goodness-of-fit statistics
Pass/Fail
Fail
Pass
Fail
Fail
Pass
Fail
Pass
Pass
*
Fail
Fail
R
-squared
0.67
0.74
0.75
0.77
RMSE
2.69
2.08
2.09
2.00
na
na
na
na
na
na
MAE
2.09
1.49
1.47
1.44
ME (bias)
−1.46
0.62
0.69
0.63
Note:
✓ represents a response consistent with predetermined intervariable correlation coefficients,
× represents an inconsistent response, - represents absence of variable in GEP model,
d
# refers
to the GEP model variable name, * indicates preferred model and na means not applicable.
Bold text indicates the goodness-of-fit statistics for the preferred model.
The Annapolis River is located within the Humid Continental Zone according to the Köppen
Climate Classification. This river flows 120 km, through rolling hills before reaching the Bay
of Fundy. It has a total catchment area of about 2000 km
2
, with the highest ranges reaching
up to 230 m above sea level. The Annapolis catchment is interesting from a modelling point
of view due to its climate conditions. Precipitation occurs throughout the whole year, being
slightly lower during summer. Snowfall is common from November until April with rare hur-
ricane weather in autumn. Although the average maximum temperature is below 0°C in January
and February, significant variation in temperature may result in milder weather and snowmelt
throughout the winter. Moreover, as average minimum temperature is below 0°C during half of
the year, freezing and melting occur frequently meaning that on account of daily variations and
seasonal changes in temperature, snowfall and snow retention pose a real challenge for hydro-
logical modellers.
The hydrometeorological data employed in this study comprised 3649 daily records span-
ning a 10-year period (2000-2010). Twelve lagged input predictors, covering
t
− 1 and
t
− 2, and
a single output predictand [
Q
(
t
)], provided a model development data set (Table 8.5). The river
discharge data were obtained from the Water Survey of Canada, for Wilmot settlement, located
at 44°56′57″, 65°01′45″W (Station Number 01DC005, Annapolis River at Wilmot, Nova Scotia:
