CLA Irrigation & Water Management Flashcards

What is 'distribution uniformity' (DU) in irrigation system design?

Answer: A measure of how evenly water is applied across the irrigated area

Distribution uniformity (DU) measures how consistently water is applied; a DU of 100% means every point receives exactly the same amount.

Which irrigation design principle ensures that all sprinkler heads in a zone have the same precipitation rate to achieve uniform coverage?

Answer: Matched precipitation rate (MPR)

Matched precipitation rate design means rotors and fixed sprays in the same zone apply water at the same rate, preventing dry or soggy spots.

What is a 'hydrozone' in landscape irrigation planning?

Answer: A grouping of plants with similar water requirements served by a dedicated irrigation zone

Hydrozoning groups plants with similar water needs on the same irrigation zone to avoid overwatering drought-tolerant plants or underwatering thirsty ones.

What does the acronym 'WUCOLS' stand for, and how is it used?

Answer: Water Use Classification of Landscape Species — a California reference guide for plant water needs

WUCOLS (Water Use Classification of Landscape Species) is a California DWR publication that categorizes landscape plants as high, moderate, low, or very low water users.

What is the function of a 'master valve' in an irrigation system?

Answer: Acts as a main shutoff that opens only when an irrigation zone is active, preventing leaks when system is off

A master valve at the main line closes when no zone is running, protecting against leaks from a broken lateral or stuck valve anywhere in the system.

When designing irrigation for a slope, which practice helps prevent runoff and promotes infiltration?

Answer: Use cycle-and-soak scheduling with multiple short run times

Cycle-and-soak applies water in multiple short cycles with rest periods, allowing the soil to absorb each application before more is added.