What is Hooghoudt equation describe in detail?
In Hooghoudt’s drainage equation, the water divide between the drains, and therefore the zone of influence of a drain, is found at a distance M=L/2 from the drain, i.e. midway between the drains.
How do you calculate drainage coefficient?
It is also expressed as the flow rate per unit area, i.e., m3/s per km2 or L/s per hectare (Lps/ha). Thus, for a 100 ha agricultural watershed, a drainage coefficient of 1 mm/day would lead to a discharge of 100 ´ 0.116 = 11.6 L/s at the outlet of the watershed (because 1 mm/day = 0.116 Lps/ha).
Which of the following is Hooghoudt’s assumption?
Hooghoudt’s assumption that the flow is radial upto a distance of D/√2 from the drains is valid. In the central zone, L – D√2, Dupuit Forchheimer assumptions are applicable. The objective of the present study is to derive a rigorous expression for the maximum height of water above the drain level.
What is a good drainage rate for soil?
around 2” per hour
The ideal soil drainage is around 2” per hour, with readings between 1”- 3” generally OK for garden plants that have average drainage needs. If the rate is less than 1” per hour, your drainage is too slow, and you’ll need to improve drainage or choose plants tolerant of wet soil.
What does high hydraulic conductivity mean?
In theoretical terms, hydraulic conductivity is a measure of how easily water can pass through soil or rock: high values indicate permeable material through which water can pass easily; low values indicate that the material is less permeable.
What is drainage coefficient?
The drainage coefficient is the design capacity of the drainage system and is typically expressed as a depth of water removed in 24 hours (inches/day). A drainage coefficient should be chosen that will economically remove excess water from the top part of the root zone within 24 to 48 hours.
What is meant by drainage coefficient?
How do you calculate the rate of drainage porosity?
Based on the cumulative volume of water drained, drainable porosity is calculated by dividing the volume of water drained with the volume of the soil sample.
What is drainage work?
Drainage is the natural or artificial removal of a surface’s water and sub-surface water from an area with excess of water.
How do you tell if soil is well drained?
To determine your soil drainage, dig a hole about 12 inches deep and 8 to 12 inches wide. Fill the hole with water. Allow it to drain, refill it 12 hours later, and time how long it takes for the water to drain. If the soil drains well, all the water should be gone in 2 to 3 hours.
How do you make good soil drainage?
Adding lots of organic matter such as compost, farm manure, or shredded leaves to clayey soil will allow it to drain more easily and hold the right amounts of water and air for better plant growth and increased biological activity. Adding sand can be tricky and typically is not recommended to be added to clay soil.
How do you calculate hydraulic conductivity example?
Mathematically, porosity is given by: n = 0.255 × (1 + 0.83ᵘ) . Therefore, n = 0.255 × (1 + 0.83⁶) = 0.3384 . You can then use Kozeny-Carman, Hazen equation, and Breyer equation to determine the hydraulic conductivity.
How do you calculate the slope of a drain tile?
My pipe diameter is:*
- Length of Pipe.
- Length of Pipe.
- Length of pipe in feet holding field.
- Min. Slope Required. (Inches Per Foot) 0.25 = 1/4.
- Min. Grade Required. (%) % Grade = 100*(rise/run)
- Total Pipe Drop. (Inches) Total pipe drop is calculated by simply multiplying the required slope by the total length of pipe.
What is drainage coefficient Mcq?
What is drainage coefficient? (a). It is the depth of water in cm to be drained in 24 hours period from the entire drainage area.
Is well drained soil dry or wet?
A well-drained soil retains water long enough for roots to absorb what the plant needs, and dries out sufficiently between rains or waterings so that roots can take up oxygen and don’t rot from too much moisture.