Geoscience Reference
In-Depth Information
World Meteorological Organization (1986).
Manual for Estimation of Probable Maximum
Precipitation
, second edition, Operational Hydrology Rept. No. 1, WMO-No.332. Geneva,
Switzerland: Secretariat of the WMO. (Table updated by the National Weather Service, Office of
Hydrology, Hydrometeorological Branch, 1992.)
Yang, D., Goodison, B. E. and Metcalf, J. R. (1998). Accuracy of the NWS 8” standard nonrecording
precipitation gauge: results and application of WMO intercomparison.
J. Atmos. Oceanic
Technol.
,
15
, 54-67.
PROBLEMS
3.1
Sketch the potential temperature versus height,
z
,
for the air parcel undergoing the changes depicted
in Figure 3.10. Indicate the different segments of the curve with the same letters A, B, C and D as
it passes over the ridge.
3.2
Show how the inverse distance method expression (3.2) produces the arithmetic mean for
b
=
0.
3.3
Using the principle underlying the inverse distance method (see Equation (3.2)), derive an expres-
sion to calculate missing precipitation data at one of the
n
rain gages in the area under consideration.
In other words, estimate the precipitation at the, say,
p
th station, with the missing data, from the
measured precipitation at the other (
n
−
1) rain gages, which are separated from it by respective
distances,
d
1
,
p
,
d
2
,
p
,...
d
n
−
1
,
p
.
3.4
Estimate the return period,
T
r
(in years), of a rain storm in which 60 mm fell over a period of
90 min, at a location where
K
p
in Equation (3.3) is of the order of 36. Use typical values for the
parameters
a
and
c
.
3.5
Suppose that rainfall intensity-duration-frequency data, for a region with a humid, temperate
climate, can be described by Equation (3.3) with the constants,
K
p
=
30
,
a
=
0
.
2
,
b
=
0
.
05 h
and
c
=
0
.
70 (with
P
in mm h
−
1
,
D
in h, and
T
r
in years). Estimate the 50 y rainfall with a
duration of 70 min.
3.6
Estimate the maximal depth ever recorded on Earth for a duration of 90 min.
3.7
By comparing Figures 3.21 and 3.22, estimate roughly what the average rainfall intensity was in
the data from which Figure 3.21 was derived; in other words, for what value(s) of
P
are these two
figures in agreement? Assume that the various gages, whose measurements were used in these two
figures, have similar hydrodynamic characteristics affecting the gage deficiencies.
