1. North-South Variations in West Coast Hydrometeorological Parameters 19
5000
4000
E
.s 3000
'5 c :J
a: 2000
Qj
>
a:
1000
oh,,-,--,--,r'-'r--r-~f'C'r''¥h-r.--r>i''''r-'''r--r-r-r.--r-r=r---i
-60 -50 -40 -30 -20 ·10 0 10 20 · 30 40 50 60 70
Degrees of Latitude
I· ·. . ·· · ·SEB
--WWB
-
WWRA
Figure 1.10. The latitudinal changes in the annual runoff computed from a)
Surface Heat Budget; b) World Water Balance; and; c) World Water Resources.
itation gauges are located in nonrepresentative areas. The averaging
technique used in this study may also have contributed to this problem.
One way of assessing the accuracy of the runoff measurements is to see
if the water balance is closed by computing the sum of runoff and
evaporation and to compare this total to the precipitation amounts. When
the WWRA runoff values are used, the sums of runoff and evaporation
compare quite well with precipitation , except for an underestimate of
precipitation at latitudes between 35°Sand 50°S. A similar pattern is
obtained using the SEB estimates. This result gives some confidence in
the WWRA and SEB runoff estimates.
Runoff-to-precipitation ratios display these differences very graphically.
They also provide some insight into the water yields of different areas.
Ratios greater than 1.0 suggest that there may be problems with either
the precipitation data or, more likely in this case, the runoff estimates.
With SEB runoff values, the ratios reach a maximum of 0.7; with WWB
values, they exceed 1.0 for mid-latitudes in both North and South
America; the WWRA values tend to be less than 1.0 except in the 10°S
to 0° band.
Runoff and streamflow are related but not equivalent. Runoff represents the amount of water which flows over the surface or in the subsurface
layer to streams, rivers, and the ocean. Streamflow refers to the water
that is carried to the oceans in river channels. As shown in Figure 1.11,
the fresh-water discharges carried in individual rivers on the western
coast of North America to the Pacific Ocean are generally much larger
5000
4000
E
.s 3000
'5 c :J
a: 2000
Qj
>
a:
1000
oh,,-,--,--,r'-'r--r-~f'C'r''¥h-r.--r>i''''r-'''r--r-r-r.--r-r=r---i
-60 -50 -40 -30 -20 ·10 0 10 20 · 30 40 50 60 70
Degrees of Latitude
I· ·. . ·· · ·SEB
--WWB
-
WWRA
Figure 1.10. The latitudinal changes in the annual runoff computed from a)
Surface Heat Budget; b) World Water Balance; and; c) World Water Resources.
itation gauges are located in nonrepresentative areas. The averaging
technique used in this study may also have contributed to this problem.
One way of assessing the accuracy of the runoff measurements is to see
if the water balance is closed by computing the sum of runoff and
evaporation and to compare this total to the precipitation amounts. When
the WWRA runoff values are used, the sums of runoff and evaporation
compare quite well with precipitation , except for an underestimate of
precipitation at latitudes between 35°Sand 50°S. A similar pattern is
obtained using the SEB estimates. This result gives some confidence in
the WWRA and SEB runoff estimates.
Runoff-to-precipitation ratios display these differences very graphically.
They also provide some insight into the water yields of different areas.
Ratios greater than 1.0 suggest that there may be problems with either
the precipitation data or, more likely in this case, the runoff estimates.
With SEB runoff values, the ratios reach a maximum of 0.7; with WWB
values, they exceed 1.0 for mid-latitudes in both North and South
America; the WWRA values tend to be less than 1.0 except in the 10°S
to 0° band.
Runoff and streamflow are related but not equivalent. Runoff represents the amount of water which flows over the surface or in the subsurface
layer to streams, rivers, and the ocean. Streamflow refers to the water
that is carried to the oceans in river channels. As shown in Figure 1.11,
the fresh-water discharges carried in individual rivers on the western
coast of North America to the Pacific Ocean are generally much larger