278
eA = (pk/(1 + pk))(J/kl
and, given that p = q + eA,
q = p _ (pk/O + pk))(J/kl,
J osep Pinol, Anna A vila and Antoni Escarre
(19.1)
(19.2)
where p = P/ET, eA = EA/ET, and q = Q/ET. The derivation of the equations
and their characteristics can be found in Hsuen-Chun (1988) and Pinol et al.
0991,1995).
By using Eqs. (19.1) and (19.2) with a k value of 2.0, the different relationships between EA and P and Q and P found at Prades, Montseny, and Hubbard Brook are shown to follow the same conceptual model (Fig. 19.1). The
IUJ
-.. «
UJ
IUJ
0
1.2
1.0
0.8
0.6
0.4
0.2
0.0
2.5
2.0
1.5
1.0
0.5
0.0
0.0
0.5
1.0
•
•
•
• t ••
•
• •
•
•
- - Eqs. 119.1) and (19.2)
with k=2 . 0
o
TM9 IMontseny)
•
THO IMontseny)
D
Avie IPrades)
•
Teula IPrades)
...
W6 (Hubbard Brook)
...
1.5
2.0
2.5
3.0
P/E T
•
3.5
Fig. 19.1. Relationships between EA/ET and P/ET (above) and between Q/ET and P/ET (below)
for catchments at Prades, Montseny, and Hubbard Brook (data taken from Federer et aJ. 1990).
Equations (19.1) (above) and (19.2) (below) are also shown with a k value of 2.0. This is an approximate mean value of those obtained by statistical fitting with actual hydrologic data of different catchments in the world by Pinol et aJ. (1991,1995)