The scour depth D of a river during flood, may be calculated from the Lacey's equation

• A. <img src="/_files/images/civil-engineering/irrigation/16-15-43-1.png">
• B. <img src="/_files/images/civil-engineering/irrigation/16-15-43-2.png">
• C. <img src="/_files/images/civil-engineering/irrigation/16-15-43-3.png">
• D. <img src="/_files/images/civil-engineering/irrigation/16-15-43-4.png">