Rapid shoreline flooding enhances water turbidity by sediment resuspension: An example in a large Tibetan lake

Abstract

Rapid water level rise due to climate change has the potential to remobilize loose sediments along shorelines and increase the turbidity of nearshore waters, thereby impacting water quality and aquatic ecosystem health. Siling Lake is one of the largest and most rapidly expanding lakes on the Tibetan Plateau. Between 2000 and 2017, this lake experienced an increase in water level of about 8 m and a doubling in water turbidity. Here, using this lake as a study site, we used a wave model and high‐resolution remote sensing of turbidity (Landsat‐8) to assess the potential connection between water‐level rise, enhanced wind‐driven sediment resuspension and water turbidity. Our analysis revealed that strong bottom shear stresses triggered by wind‐generated waves over newly flooded areas were related to an increase in water turbidity. The spatial variability of Siling Lake turbidity showed a strong dependence on local wind characteristics and fetch. Two factors combined to drive the increase in turbidity: (1) high wave energy leading to high bottom shear stresses, and (2) flooding of unvegetated shallow areas. Using a new relationship between wave energy and turbidity developed here, we expect the increase in turbidity of Siling Lake to taper off in the near future due to the steep landscape surrounding the lake that will prevent further flooding. Our results imply that rising water levels along the coast are not only expected to influence terrestrial ecosystems but could also change water quality. The methodology presented herein could be applied to other shorelines affected by a rapid increase in water level. © 2020 John Wiley & Sons, Ltd.

Drivers of suspended sediment dynamics along the shorelines of the Yellow River Delta detected from satellite data

“…Sediment transport along the YRD is mainly controlled by seasonal winds, because surface currents are weak (Wang et al, 2010). In shallow water environments, wave‐induced bed shear stress generally represents the primary mechanism for sediment resuspension (Fagherazzi & Priestas, 2010; La Forgia et al, 2019; Mi et al, 2020). Here, we calculated the bed shear stress using waves and water depth to further explore drivers of TSS variability.…”

Bridging the divide between inland water quantity and quality with satellite remote sensing: An interdisciplinary review

“…Within lakes, the connections between water quantity F I G U R E 5 An inspection of the publications on satellite remote sensing of both water quantity and water quality between 1991 and 2021 (represented in Figure 4a) indicated that only 225 of the initially identified 486 publications distinctly assess both types of parameters. fluctuations and TSS are often explored through changes in water elevation causing redistribution and mobilization of sediment (e.g., Mi et al, 2020). Another area of interest for these studies is water temperature.…”

“…Of the publications, 18% ( N = 41) of studies mention TSS (Figure 5b), with over half of them relating specifically to river discharge or flow. Within lakes, the connections between water quantity fluctuations and TSS are often explored through changes in water elevation causing redistribution and mobilization of sediment (e.g., Mi et al, 2020). Another area of interest for these studies is water temperature.…”