Hydrological Evaluation of Satellite Soil Moisture Data in Two Basins of Different Climate and Vegetation Density Conditions
Table 1
The XAJ model parameters used in the Pontiac basin (PB) and the French Broad basin (FBB), respectively.
Symbol
Model parameters
Unit
Optimal value
Range
SM
Areal mean free water capacity of the surface soil layer, which represents the maximum possible deficit of free water storage
mm
31.48; 46.37
10–50
KG
Outflow coefficients of the free water storage to groundwater relationships
[—]
0.10; 0.35
0.10–0.70
KSS
Outflow coefficients of the free water storage to interflow relationships
[—]
0.19; 0.10
0.10–0.70
KKG
Recession constants of the groundwater storage
[—]
0.31; 0.98
0.01–0.99
KKSS
Recession constants of the lower interflow storage
[—]
0.01; 0.01
0.01–0.99
CS
Recession constant in the lag and route method for routing through the channel system with each subbasin
[—]
0.26; 0.58
0.10–0.70
WUM
Averaged soil moisture storage capacity of the upper layer
mm
46.96; 40.49
30–50
WLM
Averaged soil moisture storage capacity of the lower layer
mm
39.08; 135.00
20–150
WDM
Averaged soil moisture storage capacity of the deep layer
mm
30.11; 389.01
30–400
IMP
Percentage of impervious and saturated areas in the catchment
%
0.00; 0.00
0.00–0.10
B
Exponential parameter with a single parabolic curve, which represents the nonuniformity of the spatial distribution of the soil moisture storage capacity over the catchment
[—]
0.70; 0.80
0.10–0.90
C
Coefficient of the deep layer that depends on the proportion of the basin area covered by vegetation with deep roots
[—]
0.49; 0.50
0.10–0.70
EX
Exponent of the free water capacity curve influencing the development of the saturated area
