What does ETo represent in irrigation scheduling?
Water Requirements Estimation
Question · Easy
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Which formula correctly calculates landscape water requirement (LWR) from ETo?
Question · Medium
A landscape has an ETo of 6 in/month, a Kc of 0.5, a KL of 1.0, and an irrigation efficiency of 75%. What is the monthly gross irrigation requirement?
Question · Hard
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What is MAWA as defined under California's Model Water Efficient Landscape Ordinance (MWELO)?
The Evapotranspiration Adjustment Factor (ETAF) for a special landscape area under California MWELO is set at what value?
Which soil texture has the lowest available water-holding capacity per foot of soil depth?
Soil Plant Water Relationships
What is the management allowable depletion (MAD) and why is it important for scheduling?
A CLWM measures soil moisture at 42% volumetric water content. Field capacity is 45% and permanent wilting point is 15%. What percentage of available water remains?
Which type of water source typically has the highest salinity concern for landscape irrigation?
Water Sources
When using recycled water for landscape irrigation, the sodium adsorption ratio (SAR) is important because high SAR values indicate what risk?
A water bill shows Tier 1 at $1.50/ccf for 0–5 ccf, Tier 2 at $3.00/ccf for 5–15 ccf, and Tier 3 at $6.00/ccf above 15 ccf. A property uses 22 ccf. What is the total water charge?
Economics
CIMIS is a network of weather stations used to provide which data for irrigation scheduling in California?
Which EPA WaterSense controller technology adjusts irrigation schedules based on local weather data and ET calculations without an on-site sensor?
What is the primary advantage of a soil-moisture-based smart controller over a weather-based controller?
Which hydraulic concept explains why pressure at the end of a long pipe run is lower than at the source?
Hydraulics
According to the Hazen-Williams equation, if pipe diameter is doubled while flow rate stays the same, friction loss will approximately:
What is the precipitation rate (PR) of a sprinkler system in inches per hour, given: flow rate = 2.0 gpm per head, spacing = 10 ft × 10 ft, and 96.25 conversion factor?
Sprinkler Layout Zoning
Head-to-head coverage in sprinkler layout means:
When zoning a landscape irrigation system, why should turf and shrub areas generally be on separate zones?
What does distribution uniformity (DU) measure in an irrigation audit?
Auditing
During a catch-can audit, a manager places 16 cans in a 4×4 grid under a rotary zone. After a 15-minute run, volumes collected (in mL, from lowest to highest) are: 8, 10, 12, 14 (lowest quarter), with an overall mean of 18 mL. What is the DU-LQ?
In a scheduling context, what does 'cycle and soak' (also called 'repeat scheduling' or 'multiple-start times') accomplish?
Scheduling
A CLWM calculates that a zone needs 1.5 inches of net application per week. The zone's DU is 0.70 and the system's application efficiency is 75%. What gross runtime is needed if the PR is 1.0 in/hr?
What is the purpose of a water budget in landscape water management?
Which maintenance activity most directly improves distribution uniformity in an existing rotary sprinkler zone?
System Maintenance
What does a catch-can test measure during an irrigation audit?
Which of the following is the BEST indicator that an irrigation system is running during a prohibited time under local water restrictions?
What is the primary purpose of a landscape irrigation audit report delivered to a client or water agency?
Which scheduling method adjusts irrigation runtime daily based on the prior day's ETo data?
A cool-season turf zone has an ETo of 0.25 in/day and a crop coefficient (Kc) of 0.80. The zone holds 1.5 inches of plant-available water and is managed at 50% MAD. How many days until irrigation is needed?
Which EPA WaterSense label criterion must a weather-based irrigation controller (WBIC) meet to be certified?
A landscape manager converts a spray-head zone to drip irrigation. Spray heads had a precipitation rate of 1.5 in/hr; drip emitters apply 0.05 in/hr to the same plant-water demand. The zone runtime must be adjusted by what factor?
What does an irrigation system flow sensor (master valve flow sensor combination) primarily provide?
Which maintenance problem is most commonly identified during a routine irrigation inspection of rotor heads?
Simple payback period for a system upgrade is calculated as:
A commercial property currently uses 8 acre-feet per year for irrigation. After a recommended upgrade, use is projected to drop to 5 acre-feet per year. At $800/acre-foot, what is the annual dollar savings?
Which factor is most important when comparing the economic benefit of converting from overhead spray to drip irrigation on a mixed shrub border?
Under California's MWELO, the applied water use compliance threshold (ETWU) must be less than or equal to MAWA. If a landscape applies 120% of MAWA, which corrective action addresses the root cause of non-compliance most directly?
Which of the following irrigation system components is specifically designed to prevent contamination of the potable water supply from backflow?
When designing a conservation program for a municipal water utility, which metric best measures whether the program is achieving meaningful demand reduction?
A CLWM is presenting audit findings to a commercial property manager. Which approach is most effective for gaining buy-in on recommended improvements?
Which soil amendment most effectively improves water infiltration and availability in a heavy clay soil before establishing landscape plants?
Field capacity (FC) is defined as:
Why do slopes require special scheduling considerations in landscape irrigation?
Which groundwater-supplied irrigation scenario presents the highest long-term sustainability concern?
What does electrical conductivity (EC) measure in irrigation water quality testing?
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