BRAE 340 EXAM 3 questions well answered already passed

BRAE 340 EXAM 3 questions well
answered already passed

Basic Ideas of Irrigation - correct answer ✔✔1) good uniformity

2) correct depth

3) minimize losses



What are the two scheduling Q? - correct answer ✔✔1) When to irrigate

2) How much to applied



Scheduling Technique - When? - correct answer ✔✔Indicator Threshold

- SMD vs. Time

- SMC vs. Time

- SMT vs. Time



Scheduling Technique - How much? - correct answer ✔✔Weather based approach

- target depth (CIMIS)

- pre infiltration losses

- DU

By Feel Method

- soil samples at different depths

- several locations in the field



Distribution Uniformity (DU) - correct answer ✔✔- measure of how uniformly the water is
distributed throughout a field

, - always less than 1

- always a decimal value

- typical DU = .80



DU Calculations - correct answer ✔✔= DminD/Dave



Gross VS Net Used Theory - correct answer ✔✔An irrigation system that does not apply water
uniformly must apply excess water in some areas in order that there is enough water in other
areas



Excess Water = ? - correct answer ✔✔surface runoff and deep percolation



Efficiency - correct answer ✔✔- Describes how much of the water was beneficially used

- total amount of water was too much or too little

- surface losses



Efficiency Calculation - correct answer ✔✔= Water Beneficially used/Total Water applied

*expressed as a percentage



Two Efficiency Terms - correct answer ✔✔1) Irrigation

2) Application



Irrigation Efficiency - correct answer ✔✔- field, farm, district, basin

- very strict accounting of water destinations

- single event or annual



Application Efficiency - correct answer ✔✔- field