How to Calculate and Solve for Bottom Width for the Most Hydraulic Efficient Cross-Section | Irrigation Water Requirement

The image above represents the bottom width for the most hydraulic efficient cross-section. To calculate the bottom width for the most hydraulic efficient cross-section, two essential parameters are needed, and these parameters are Design Depth (d) and Side Slope Ratio (z).

The formula for calculating the bottom width for the most hydraulic efficient cross-section:

b = ^2d / _{[z + (z² + 1)^0.5]}

Where:

b = Bottom Width for the Most Hydraulic Efficient Cross-Section
d = Design Depth
z = Side Slope Ratio

Let’s solve an example;
With a design depth of 42 and a side slope ratio of 2. Find the bottom width for the most hydraulic efficient cross-section?

This implies that;

d = Design Depth = 42
z = Side Slope Ratio = 2

b = ^2d / _{[z + (z² + 1)^0.5]}
b = ²⁽⁴²⁾ / _{[2 + ((2)² + 1)^0.5]}
That is, b = ⁸⁴ / _{[2 + (4 + 1)^0.5]}
b = ⁸⁴ / _{[2 + (5)^0.5]}
b = ⁸⁴ / _{[2 + 2.236]}
Then, b = ⁸⁴ / _4.236
b = 19.829

Therefore, the bottom width for the most hydraulic efficient cross-section is 19.829.

Read more: How to Calculate and Solve for Gross Irrigation Requirement | Irrigation Water Requirement

How to Calculate the Bottom Width for the Most Hydraulic Efficient Cross-Section With Nickzom Calculator

Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the bottom width for the most hydraulic efficient cross-section.

To get the answer and workings of the bottom width for the most hydraulic efficient cross-section using the Nickzom Calculator – The Calculator Encyclopedia. First, you need to obtain the app.

You can get this app via any of these means:

Web – https://www.nickzom.org/calculator-plus

To get access to the professional version via web, you need to register and subscribe for NGN 2,000 per annum to have utter access to all functionalities.
You can also try the demo version via https://www.nickzom.org/calculator

Android (Paid) – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator
Android (Free) – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator
Apple (Paid) – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Agricultural under Engineering.

Now, Click on Irrigation Water Requirement under Agricultural

Now, Click on Bottom Width for the Most Hydraulic Efficient Cross-Section under Irrigation Water Requirement

The screenshot below displays the page or activity to enter your values, to get the answer for the bottom width for the most hydraulic efficient cross-section according to the respective parameters which is the Design Depth (d) and Side Slope Ratio (z).

Now, enter the values appropriately and accordingly for the parameters as required by the Design Depth (d) is 42 and Side Slope Ratio (z) is 2.

Finally, Click on Calculate

As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the bottom width for the most hydraulic efficient cross-section and presents the formula, workings and steps too.