3.5 Inter-Annual Variability in Floodplain Connectivity
Our modeled river-floodplain system connectivity dynamics differed
across years reflecting the influence of inter-annual variability in the
timing and magnitude of seasonal snowmelt hydrographs (Figure 9). To
measure the inter-annual variability (henceforth called total
sensitivity), at each intermittently connected target site we calculated
the difference between years with the highest and lowest values of
duration (% of period) within three connectivity states: high
(σm > 0.6), intermediate (0.4 <
σm > 0.6) and low connectivity
(σm < 0.4) (Table 2). Total sensitivity ranged
between 16 to 22% for duration of high connectivity, 6 to 16% for
intermediate connectivity, and 10 to 25% for low connectivity (Figure
9a). Along with generally lower total sensitivity for intermediate
connectivity, the duration that sites spent in intermediate connectivity
was also low, with intermediate connectivity duration ranging between
5% to 26% of the study period across all intermittently connected
target sites and years (Table 2, Figure 9a). This sensitivity is also
reflected in the exceedance probabilities (% of period) of the percent
of intermittent sites in high, intermediate and low connectivity states.
As one would expect, in wetter years, intermittent sites remained in a
high connectivity state for longer, while in dry years these sites had
longer durations in low connectivity states (Figure 9b).