From: on behalf of Panel Registry Subject: FW: TNG registration of ...

Source:
Theo Mlynowski, UNBC
Precipitation
Similar to temperature, Mean Annual Precipitation (MAP) – which concerns both rain and
snow – is the average of wet and dry extremes measured every day throughout the course
of a year. Figure 6 shows a general increase of MAP throughout the following periods: (a)
1961 – 1990, (b) A1F1 2020’s, and (c) A1F1 2050’s.
At present, the MAP for the period 1961‐1990 for the XGCA is 901‐mm. Figure 5 illustrates
that the bulk of the precipitation happens in the mountains, whereas the low lying areas of
the territory are a bit dryer. Map 6b and 6c show that the future A1F1 scenario predicts an
increase in annual precipitation of 44‐mm and 104‐mm for the 2020’s and 2050’s,
respectively. In comparison, the B2 scenario (not shown in the Figure) predicts a slightly
drier future with an increase in precipitation of 21‐mm and 36‐mm for the 2020’s and
2050’s,
respectively. A large portion of the increase in precipitation will take place in the
mountains, as illustrated by the dark blue patterns.
<strong>From</strong> the effects of a warmer climate, the percent of precipitation in the form of snow is
expected to decrease. Throughout the period 1961 – 1990, roughly 60 % of precipitation
was snow. The A1F1 scenario predicts a decrease to 57% by the 2020’s, and 52% by the
2050’s. Likewise, the B2 scenario predicts a decrease to 58% by the 2020’s and 56% by the
2050’s.
Figure 6: Mean annual precipitation for the Chilko River watershed throughout the
following 1961­1990. Change in mean annual precipitation (in reference to
the 1961 – 1990 values) is shown for b) 2020’s A1F1 scenario, and c) 2050’s
A1F1 scenario.
Source: Theo Mlynowski, UNBC
As with temperature above, the study prepared a graph that compares the precipitation
level of the Chilko Watershed to the one expected at the Xeni Gwet’in Government office.
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