What seasonal phenomenon affects the cleanliness of water taken from lakes?

Lake turnover is a significant seasonal phenomenon that impacts the cleanliness of water taken from lakes. This process typically occurs during the fall and spring seasons as water temperature changes. In the fall, the surface water cools, causing it to become denser and sink. This movement brings nutrient-rich water from the bottom of the lake to the surface, while also mixing dissolved oxygen throughout the water column.

The increased mixing can disturb sediments, releasing nutrients and contaminants that may have settled on the lake bottom. This can lead to fluctuations in water quality, potentially increasing pollutants and affecting clarity. During the spring turnover, similar processes occur as the ice melts and warmer water rises, allowing for another cycle of mixing.

Overall, lake turnover plays a crucial role in maintaining the ecological balance of aquatic systems while simultaneously affecting the cleanliness and clarity of water. Understanding this phenomenon helps explain the variations in water quality and the importance of seasonal changes in lake ecosystems.