What is reservoir stratification?

Reservoir stratification refers to the layering of water within a reservoir that occurs as a result of differences in temperature and density. In many bodies of water, warmer water is less dense and tends to stay on the surface, while cooler water is denser and sinks to the bottom. This leads to distinct layers, typically known as the epilimnion (warm surface layer), metalimnion (thermocline or middle layer), and hypolimnion (cold bottom layer).

As the seasons change, this stratification can shift, affecting water chemistry, aquatic life, and the physical characteristics of the reservoir. Understanding reservoir stratification is crucial for managing water resources, fisheries, and ecological health, as it influences oxygen levels, nutrient distribution, and the overall productivity of aquatic ecosystems.

Other options do not accurately reflect the concept of stratification; for example, filling or draining a reservoir pertains to its management and operational processes, while the advent of aquatic species relates more to biodiversity rather than the physical layering of water.