The hydraulic conductivity of a soil is 4.3 cm h⁻¹. Using the drainage‑spacing formula D = √(4KH / q), where K is the conductivity in m s⁻¹, H is the depth of the impermeable layer (3 m), and q is the permissible discharge per metre of drain (0.0002 m³ s⁻¹ m⁻¹), calculate:
(a) the theoretical drain spacing D in metres, rounded to the nearest metre;
(b) the minimum practical spacing that is a multiple of 5 m and does not exceed the theoretical spacing;
(c) the permissible discharge q that would be required to allow a practical spacing of exactly 5 m. Give q in scientific notation (m³ s⁻¹ m⁻¹) to three significant figures.
Provide the answer as "D = X m; Practical spacing = Y m; Required q = Z ×10⁻⁶ m³ s⁻¹ m⁻¹".

Question

The hydraulic conductivity of a soil is 4.3 cm h⁻¹. Using the drainage‑spacing formula D = √(4KH / q), where K is the conductivity in m s⁻¹, H is the depth of the impermeable layer (3 m), and q is the permissible discharge per metre of drain (0.0002 m³ s⁻¹ m⁻¹), calculate:
(a) the theoretical drain spacing D in metres, rounded to the nearest metre; 
(b) the minimum practical spacing that is a multiple of 5 m and does not exceed the theoretical spacing; 
(c) the permissible discharge q that would be required to allow a practical spacing of exactly 5 m. Give q in scientific notation (m³ s⁻¹ m⁻¹) to three significant figures.
Provide the answer as "D = X m; Practical spacing = Y m; Required q = Z ×10⁻⁶ m³ s⁻¹ m⁻¹".

Accepted Answer

D = 1 m; Practical spacing = 5 m; Required q = 5.73×10⁻⁶ m³ s⁻¹ m⁻¹

Waec Model Questions Vol1 2020 Geography Question 30

Answer Options

About This Question

Master the Exam!