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. Author manuscript; available in PMC: 2022 Jan 1.
Published in final edited form as: Ecol Indic. 2021 Jan 1;122:10.1016/j.ecolind.2020.107241. doi: 10.1016/j.ecolind.2020.107241

Figure 6.

Figure 6.

Distributions of deviations in lake water-level from least-disturbed conditions by lake HydrAP ranks and ecoregion for sampled lakes in NLA 2007 survey. Excessive and suppressive lake water-level fluctuation were estimated by calculating differences in log-transformed observed and mean expected lake water-level decline scaled by lake morpometry. Expected lake water-level decline was based on regional least-disturbed conditions in natural lakes. Vertical water-level decline was scaled by maximum lake depth, and horizontal water-level decline was scaled by the squareroot of lake surface area. Values were log10 transformed and standardized (z-score) by subtracing from the mean and dividing by the standard deviation for regional reference lakes. Red horizontal line represents expected water-level change under least-disturbed conditions. Kruskal-Wallis tests (p-value) were performed to test for differences in mean lake water-level change among HydrAP ranks within each ecoregion.