Research Article

Relative Contribution of the Topographic Influence on the Triangle Approach for Evapotranspiration Estimation over Mountainous Areas

Table 2

The mean value and relative error (RE) of the surface parameters and energy fluxes before and after the topographic correction for the different terrain aspect angles over the selected area.

Correct (0–45°) (45°–90°) (90°–135°) (135°–180°) (180°–225°) (225°–270°) (270°–315°) (315°–360°)

NDVI0.740.730.720.710.720.720.730.73

(K)Before299.28299.06299.27299.55299.65299.46299.40299.44
After300.44299.89299.92300.42301.16301.96302.41301.44
RE (%)0.390.280.220.290.500.831.010.67

AlbedoBefore0.1180.1220.1260.1270.1270.1220.1150.115
After0.1200.1240.1270.1290.1290.1270.1200.118
RE (%)1.691.640.791.571.574.104.352.61

Daily   
(W m−2)
Before370.37368.48367.14366.38366.02367.13370.23370.99
After366.03365.35364.63363.00360.16357.45358.50363.32
RE (%)−1.17−0.85−0.68−0.92−1.60−2.64−3.17−2.07

Daily   
(W m−2)
Before46.9847.447.9349.6048.9348.9948.4347.75
After46.4847.0347.6349.2048.2047.7946.9846.79
RE (%)−1.06−0.78−0.63−0.81−1.49−2.45−2.99−2.01

EFBefore0.430.440.430.420.410.420.430.42
After0.350.390.390.360.310.250.220.28
RE (%)−18.6−11.4−9.3−14.3−24.4−40.5−48.8−33.3