Can you tell these lines of the reservoir apart?

Reservoir

It is a flood control project

trump card

Plays a role in regulating floods

Important role

When planning and designing a reservoir

will

Reasonable determination of various storage capacities

and the corresponding reservoir water level

For engineering use

Provide a basis for normal work

Today we will learn about

Reservoir characteristic water level

and its classification

Reservoir characteristic water level

In order to complete different tasks, reservoir projects need to control or allow various reservoir water levels to drop to or be allowed to drop to at different times of the year and under various hydrological conditions. These levels are collectively referred to as reservoir characteristic water levels.

Classification of reservoir characteristic water level

The characteristic water levels of reservoirs mainly include normal water storage level, dead water level, flood control limit water level (flood limit water level), flood control high water level, design flood level, and verified flood level.

There are so many classifications of water levels

What is the difference?

What is the effect?

Normal water level

Under normal operation of the reservoir, the high water level that should be stored when water supply begins to meet the requirements of benefits is formerly called the normal high water level, the benefits water level, and the designed water storage level.

It determines the scale, efficiency and regulation method of the reservoir, and also largely determines the size, type and flooding loss of hydraulic structures and the reservoir. It is the most important characteristic water level of the reservoir.

Dead water level

The lowest water level that a reservoir is allowed to draw down to under normal operation is called the design low water level. The water level of a daily regulating reservoir changes greatly during the dry season, and generally draws down to the dead water level once every 24 hours; an annual regulating reservoir generally draws down to the dead water level at the end of the designed dry year water supply period; a multi-year regulating reservoir only draws down to the dead water level at the end of the dry period of a group of consecutive dry years. The range of variation between the normal water level and the dead water level of a reservoir is called the reservoir drawdown depth.

Flood control limit water level

Also known as the flood season limit water level, it is the upper limit water level of the reservoir during the flood season for water storage and is also the starting water level for flood control in the flood season. The flood control limit water level is the key to coordinating the relationship between flood control and water storage. It has a direct impact on the flood control benefits of the project, the benefits of power generation and irrigation, the elevation of water diversion in the reservoir, the navigable water depth, siltation, and reservoir inundation indicators. When conducting specific research, it should be combined with the project development conditions and selected after comprehensive analysis and comparison.

Flood control high water level

The highest water level reached in front of the dam when the reservoir encounters the design flood of the downstream flood protection object. This water level needs to be determined only when the reservoir undertakes the downstream flood protection task.

Design flood level

The highest water level in front of the dam when the reservoir encounters the design flood of the dam. It is the highest water level allowed for the reservoir under normal operation and one of the main bases for stability calculation of water retaining structures.

Check flood level

The highest water level in front of the dam when the reservoir encounters a dam check flood. It is the highest water level allowed to be reached in a short period of time under emergency conditions and is the main basis for determining the dam top height and conducting dam safety checks.

Do you understand the difference?

Source: "Encyclopedia of Chinese Water Resources" (Second Edition)