BRAE Midterm 1 Problem Sets & Top Hat Questions (UPDATED 2022) with COMPLETE SOLUTION

BRAE Midterm 1 Problem Sets & Top Hat Questions (UPDATED 2022) with COMPLETE SOLUTION What is the common method for describing how much water to apply to meet the crop needs? a Inches b Gallons per minute c Cubic f ...

BRAE Midterm 1 Problem Sets & Top Hat Questions (UPDATED 2022) with COMPLETE SOLUTION What is the common method for describing how much water to apply to meet the crop needs? a Inches b Gallons per minute c Cubic feet d Acres - ✔✔A. Inches Which of the following is considered a beneficial use of water? a Wind drift b Deep percolation c Uncollected runoff d Soil preparation - ✔✔D Soil Prepation Which of these can be a unit of pressure? a ft b gal c sq in d acre-in - ✔✔A. Feet An alfalfa crop uses 0.32 inches per day. How many days will it take to extract 4.52 inches from the soil? - ✔✔o 4.52 / 0.32 = 14.25 days 14.1 An elevated water tank is used to feed water into a drip system. How high (feet) must the tank outlet be in order to have 26 psi pressure at the inlet to the drip system? - ✔✔26 psi x 2.31 ft = 60.06Water has been turned into a 4 acre reservoir until it stands 3 inches deep. What volume of water has been added in ac-ft? a 1 b 7 c 12 d 0.75 - ✔✔A. 1 12/ 12 A pump must deliver water to an irrigation system on the top of a hill, which is 192 feet above the pump. What should the pump outlet pressure (psi) be in order to raise water just to the top of the hill (ignore losses)? - ✔✔o 1 psi = 2.31 feet o 192 feet / 2.31 feet = 83.12 What salinity (ds/m) is equivalent to a soil moisture tension of 0.43 bars? a 1.23 b 1.43 c 1.54 d 1.70 - ✔✔0.43 bars / 0.3 bars = 1.43 ds/m B A metric sprinkler catalog shows a sprinkler that delivers 0.50 liters per second (Lps) at an operating pressure of 314 kiloPascals (kPa). What is the sprinkler operating pressure in feet of water? - ✔✔Convert kPa into feet of pressure 314 kPa x (1psi / 6.906 kPa) x (2.31 ft / 1 psi) = 105.2 An irrigation system applies a gross amount of 45 inches of water during the growing season. An evaluation determines that: 28 inches goes to satisfy crop ET; 9 inches runs off and is not collected for reuse; 4.8 inches passes through the root zone as deep percolation (total deep percolation), of which 1 inch is beneficial leaching for salt removal; and 1 inch is ET from weeds. What would the efficiency be if the gross application was reduced because the runoff was eliminated? a 64.4%b 70.5% c 80.6% d 92.1% - ✔✔o Eff = 28 + 1 / 45 = 29/45= 64.4 • 29 / (45 - 9) = 29/36 = 80.6% *runoff was eliminated C. 80.6% A pumping rate of 737 gpm will deliver how many inches to a field of 142 acres in 71 hours? - ✔✔In / hr = GPM x 96.3 / Area In = GPM x 96.3 x hr / Area • 142 acres x (43560 sq-ft / 1 acre) • 737 x 96.3 x 71 / 6185520 = .815 T/F: DU is expressed as a percentage. - ✔✔False KNOW HOW TO DO THE RAIN GUAGE QUESTION AKA FUNNEL ONE - ✔✔ KNOW THE WATER DIAGRAM - ✔✔ What is perfect timing? - ✔✔Driest part of the field absorbs water California's agriculture uses about what percent of its developed water supply? a 10% b 40% c 50% d 80% - ✔✔B. 40% T/F: With regards to water marketing, the term 'third party impacts' refers to the potential loss of income to agricultural suppliers, farm workers and related industries if farmers sell their water and quit farming. - ✔✔TrueTo which water right/doctrine does the following descriptive phrase best apply? Water rights of cities descended from small towns established during Spanish era in California. a Public Trust Doctorine b Federal Reserve Rights c Riparian Rights d Pueblo Rights - ✔✔D. Pueblo Rights To which water right/doctrine does the following descriptive phrase best apply? Based on English Common Law. a Public Trust Doctorine b Pueblo Rights c Riparian Rights d Appropriative Rights - ✔✔C. Riparian Rights Which of the water institutions listed below does each descriptive phrase best apply? Cooperative group of Federal and State water-related agencies. a Irrigation District b US Army Corps of Engineers c CALFED d EPA e USBR f DWR - ✔✔C. CALFED To which of the water institutions listed below does each descriptive phrase best apply? Operates State Water Project (SWP) a US Army Corps of Engineers b Irrigation District c EPAd DWR e CALFED f USBR - ✔✔D. DWR T/F: More than 65 water agencies in California operate groundwater recharge programs to facilitate the conjunctive' (or joint, coordinated) use of surface and groundwater supplies. - ✔✔True 103 acres of crop requires 33 in (net) of irrigation per year. Water costs $62/ac-ft. How much could be saved on the annual water cost if the IE were improved from 75% to 80%? a $1235/yr b $1583/yr c $1463/yr d $1033/yr e $744/yr - ✔✔C. $1463 / year LOOK AT WRITTEN SHEET Which of these is not a component of energy? a Velocity Head b Friction c Pressure d Elevation - ✔✔B. Friction As the flow rate decreases in a system, what happens to the friction? a Increases b Decreases c Remains the same d Flow rate has not impact on friction - ✔✔B. Decreases