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Measurement of Depth of Water

The depth of water is measured by the subsequent methods are given bellow. this is often a neighborhood of hydrographic survey.
The depth of water is measured by three methods:

1. Sounding Rod

This passage talks about a tool called a sounding rod used to measure how deep small rivers are. Let’s break it down:

About the Sounding Rod

  • The sounding rod is made of wood or bamboo.
  • It’s a pole that’s 5 cm wide (across).
  • The pole is 2.5 meters long.
  • There’s a round disc at the bottom of the pole, and it’s 15 cm wide.

Measurement Details

  • The pole has markings in meters and tenths of a meter, making it good for measuring depth very precisely.

Best for Small Rivers

  • This sounding rod is best suited for measuring the depth of small rivers, usually around two meters deep.

How to Use It

  • To find out how deep the water is, you slowly put the sounding rod straight down into the water from a boat at a specific spot.
  • The disc at the bottom of the rod is made to touch the bottom of the river when the rod reaches it.
  • You can figure out the depth by looking at the markings on the rod, showing how much of it is underwater.

In short, the sounding rod is a simple tool for measuring small river depths. It’s easy to use, has clear markings for accurate readings, and you find the depth by putting it in the water until the bottom part touches the riverbed.

The level of water is then noted from the graduation (Fig. 13.6).

Depth Of Water

2. Sounding Cable

When the depth of water is quite 2 m and water current is high, the speed rod isn’t practicable.

Hence this case, a cable or rope is released slowly from a ship by means of a pulley system (Fig. 13.7).

Depth Of Water

This way of figuring out how deep a river is involves using a heavy cable with a weight at one end. Here’s how it works:

  • Cable and Weight: Imagine a strong rope with a weight of about 5 kg at one end.
  • Dropping the Cable: We drop this rope into the water until it just touches the bottom of the river. The heavy weight helps the rope sink to the riverbed.
  • Making a Mark: When the rope reaches the riverbed, a mark is made on the rope. This mark shows the water level at that exact spot in the river.
  • Measuring the Depth: After pulling the rope out of the water, we use a tape measure to figure out how long the rope is from the mark to the end that was above the water. That length tells us how deep the river is at that spot.

So, by using the weight to sink the rope and making a mark when it touches the riverbed, we can measure how deep the water is in that specific area. It’s a simple way to estimate the depth of a river.

3. Echo-sounder

The echo-sounder is employed for measuring depths of enormous rivers, in way over 10 m, and people of seas.

It’s an electrical instrument, during which a sound impulse from the surface of water is shipped towards the bottom level of the river or sea (Fig. 13.8).

Depth Of Water

This paragraph talks about using a special device called an echo-sounder to find out how deep water is. Here’s a simpler breakdown:

Sound Waves and Echo

  • Imagine sending sound waves down into the water.
  • These waves hit the bottom of the water and bounce back, like an echo.

Automatic Recording

  • A device catches this echo, the reflected sound waves.
  • It automatically records how long it takes for the sound waves to go down to the bottom and come back up.

Speed of Sound in Water

  • We assume that sound travels at a speed of about 1,470 meters per second in water.

Finding Depth

  • By knowing how long the sound takes for the round trip and the speed of sound in water, we can figure out how deep the water is.

Where to Put the Echo-Sounder

  • The echo-sounder is usually put right at the water’s surface.
  • This is to make sure we get a really accurate measurement by preventing the loss of the signal as it travels through the water.

So, in simple terms, we use the echo-sounder to send and catch sound waves, record their travel time, and then calculate the water depth using the speed of sound. Placing the device at the water surface helps us get a super accurate result.

About Post

Here in this post we have covered the three methods to measure the Depth Of Water.

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