Geoscience Reference
In-Depth Information
Figure 6.14.
River system for the Arctic terrestrial drainage based on the STN-30
digital network and location of discharge gauging stations for basins with areas greater
than 10,000 km
2
(from Lammers et al.,
2001
, by permission of AGU).
the drainage, the total gauged area did not surpass 50 percent until 1964. Since 1985,
there has been a large decrease in the number of gauges over Eurasia. Fortunately,
this has not significantly reduced the total monitored area as the gauges no longer in
operation are usually not the most downstream gauges.
6.5.2
The Major River Systems
Most of the river discharge to the Arctic Ocean is delivered through a small number
of large rivers. Following from the previous discussion, only twelve hydrological
gauges are sufficient to capture 91 percent of the total monitored area and 85 per-
cent of the total monitored discharge (Shiklomanov et al.,
2000
, Lammers et al.,
2001
). The four largest drainage basins (the Ob, the Yenisey, the Lena, and the
Mackenzie; see
Figure 2.8
) contribute about 68 percent of the total gauged volume
