Abstract:
We estimated the rainfall interception loss (
I
), canopy storage capacity (
S
), the ratio of
mean evaporation rate from the wet canopy (
E
) over the mean rainfall intensity (
R
) (mm
h
-1
) (
R
E
/
), and free throughfall coefficient (
p
) in a
Fraxinus rotundifolia
Mill.
stand
located in an afforested Park land in a semiarid re
gion of Iran. For each storm event,
I
was calculated as the gross rainfall (
GR
) minus throughfall (
TF
).
S
was estimated by
indirect methods: the minimum, the mean, and the Ga
sh and Morton. Fifty-five rainfall
events were recorded (cumulative
GR
197.2 mm), with 31 events occurring during the
growing season
(total
GR
88.0 mm) and 24 events measured during the non-gro
wing
season (total
GR
109.2 mm). The mean ratio of
I
to
GR
equalled 39.2% during the
growing season
vs
. 23.9% during the non-growing season. For the grow
ing season,
S
was
estimated to be 0.27, 0.21, and 0.23 mm using the m
inimum, mean, and Gash and Morton
methods, respectively. For the non-growing season,
these values were estimated to be 0.17,
0.13, and 0.15 mm, respectively. During the growing
and non-growing seasons,
R
E
/
were
estimated to be 0.13 and 0.11, respectively, with t
he corresponding
p
values of 0.39 and
0.52. The loss of the leaves resulted in decline in
I
,
S
, and
R
E
/
, and increase in
p
. For
semiarid regions, these values are useful for solvi
ng some water management problems.
Keywords
: Canopy storage capacity, Free throughfall coeffic
ient, Seasonal variability.
