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).