PART 2 Flashcards
Area which contributes runoff or drains water into the reservoir (PAES 609:2016).
Watershed
A thermometer that has a constriction above the bulb that permits the mercury to rise in the
capillary tube but does not allow it to descend the capillary tube unless the thermometer is
reset (PAGASA, 2022).
Maximum thermometer
The science that encompasses the occurrence, distribution, movement and properties of the
waters of the earth and their relationship with the environment (USGS, 2022).
Hydrology
The study of the biological, chemical, and physical features of lakes and other bodies of fresh
water (Oxford Languages, 2022)
Limnology
A branch of meteorology and hydrology that studies the transfer of water and energy between
the land surface and the lower atmosphere (Wikipedia, 2022).
Hydrometeorology
Heavy rainfall or rain that accumulates at a rate of 3 tenths of an inch (0.3 inch or about 7.5
mm), or more, per hour (US National Weather Service, 2022)
Torrential rain
Dominant form of precipitation in the Philippines.
RAINFALL
Kind of thermometer with pin inside its tube which does not go with the expanding liquid when
temperature increases.
Minimum thermometer
Method of areal rainfall determination done by computing the weighted average.
Arithmetic method
An instrument to measure depth of rainfall.
Rain gage
Part of rainfall which runs off the soil as surface or subsurface flow.
Runoff
Ratio of runoff over rainfall.
Runoff coefficient
The part of rainfall that is stored in the root zone and can be used by the plants (FAO, 2022).
This excludes rainfall that does not reach the soil and percolation below the root zone. For
grassed soil surface, it is estimated that this rainfall is greater than 0.5 mm/day.
Effective rainfall
The inverse of the probability of exceedance of a certain hydrologic event.
Return period
Airmass lifting process which is mountain-facilitated.
Orographic
Airmass lifting process facilitated by sunlight or heating.
Convective
Indicates to what depth liquid precipitation would cover a horizontal surface in an
observation period if nothing could drain, evaporate or percolate from this surface
(Graf-Water, 2022).
Precipitation depth
The precipitation depth that corresponds to a liquid quantity of 1 liter falling into a 1 square
meter of ground area.
1 mm
Probability of occurrence in any year of hydrologic event recurring once in 4 years.
P=(1/Return Period)x100
25%
What is the probability of occurrence in any year of a hydrologic event recurring every year?
100%`
Rainfall depths recorded were as follows: 8mm and 2mm for 8:00 A.M. and 2:00 P.M.,
respectively on 7-7-2022 and 5 mm and 9 mm for 8:00 A.M. and 2:00 P.M., respectively on
7-8-2022. What is the total rainfall depth on 7-7-2022?
2 mm
Rainfall on 7-7-2022 = Rainfall at 2:00 P.M. on 7-7-2022 + Rainfall at 8:00 A.M. on 7-8-2022
= 2 mm + 5 mm
= 7 mm
The agrometeorological station uses electronic rain gage. The rainfall depths were recorded on
June 1, 2022 as follows: 2 mm from 6:00 to 8:00 A.M., 7 mm from 8:00 to 10:00 A.M., 9 mm
from 12:00 noon to 2:00 P.M. and zero rainfall for all other times of the day and the previous
day. What is the rainfall intensity recorded on June 1, 2022?
4 mm/hr
Intensity = Depth/Time, time is from 8:00 AM of current day to 8:00 AM of the next day
= (7mm from 8:00 to 10:00 A.M. + 9mm from 12:00 noon to 2:00 P.M.)/(2hr +2 hr)
= 4 mm/hr
Estimate the time of concentration of a certain watershed having a time lag
1.43 hours
TC = TL / 0.70
= 1 hr / 0.70
= 1.43 hrs
The maximum permissible water velocity for clay loam canal surface based on PAES
603:2016.
0.80 m/s
The minimum permissible velocity for water with sediments in lined canals based on PAES
603:2016.
0.9 m/s
Application of water in the soil to supply moisture needed for plant growth.
Irrigation
Loss of water from a channel during transport due to seepage and percolation.
Conveyance loss
Depth of water flow where the energy content is at minimum hence, no other backwater forces are
involved
Critical depth
Ratio of the actual crop evapotranspiration to its potential evapotranspiration.
Crop coefficient
Moisture content of the soil when gravitational water has been removed.
Field capacity
Number of days between irrigation applications.
Irrigation interval
Removal of excess water.
Drainage
Elevated section of open channel used for crossing natural depressions.
Flume
Surveying instrument used for determining land areas in a topographic maps.
Planimeter
Elevation of water surface in a stream with reference to a certain datum
STAGE
Facility for determining water consumptive use of crops in an open field.
Lysimeter
Time required to cover an area with one application of water.
Irrigation period
At optimal emitter spacing, drip emitter spacing is ___ of the wetted diameter estimated from
field tests.
80%
Reference crop evapotranspiration is the rate of evapotranspiration from a reference surface
which is a hypothetical reference crop with an assumed crop height of 0.2 m and an albedo of
_______ (AMTEC, 2020).
0.23
Manufacturer’s coefficient of variation is the measure of the variability of discharge of a random
sample of a given make, model and size of emitter, as provided by the manufacturer and before
any field operations or aging has taken place determined through a discharge test of a sample of
50 emitters under a set pressure at ___ ºC.
A. 200 B. 100 C. 50 D. 30
way asnwer c tambong
Which one is the flattest canal side slope?
4:1
Determine the side slope angle Ө with the horizontal plane of an unlined canal with side
slope ratio (run: rise) z of 2:1.
26.6º
tan Ө = rise /run
Ө = arctan (rise /run)
= arctan (1/2)
= 26.6º
If the most efficient concrete canal has its side angle Ө with the horizontal plane equal to 60º,
what is the z value of the canal sides or the side’s horizontal run in meters per 1 meter rise?
This value is commonly used in designing most efficient concrete canals.
0.577
tan Ө = 1 / z
tan 60º = 1 / z
1.732 = 1 / z
z = 0.577
What is the top width at water surface level of the most efficient concrete open channel if the
design depth is 5 meters? The design discharge is 100 m3
/s and velocity is 2 m/s
12.9 m
What is the total top width of the most efficient concrete open channel if design depth is 5
meters? Design discharge is 100 m3
/s and velocity is 2 m/s. Use 15% freeboard.
13.8 m
What is the base of the most efficient trapezoidal concrete open channel if discharge is 100
m3
/s and velocity is 2 m/s?
6.14 m
What is the bottom width for the best hydraulic cross-section (best proportion) of concrete
open channel if design depth is 5 meters and side slope is 45º?
4 m
What is the bottom width for best hydraulic cross-section of unlined open channel for
minimum seepage if design depth is 5 meters and side slope is 45º?
8.15 m
What is the bottom width for best hydraulic cross-section of unlined open channel with
minimum seepage if design depth is 5 meters and side slope is 2:1?
4.72 m
Estimate the width and depth of concrete-lined rectangular open channel for water velocity of
2 m/s and discharge of 10 m3
/s.
3.2 m, 1.6 m
What should be the base and depth of concrete-lined rectangular open channel for a crosssectional area of 50 m2
? Design for efficiency over proportion.
10 m, 5 m
What should be the depth and side angle with the horizontal of concrete-lined triangular open
channel for a cross-sectional area of 50 m2
?
7 m, 45º
What design depth of open channel would you recommend to carry 100 cumecs or cubic
meters/sec with a velocity of 5 mps? Use the most efficient of all trapezoidal cross-sections.
3.4 m
If the most efficient of all trapezoidal cross-sections can be used, what actual depth of open
channel would you recommend to carry 100 cumecs with a velocity of 5 mps? Use 15%
freeboard.
3.9 m
If an unlined trapezoidal canal with best hydraulic cross-section can be used, what actual
depth of open channel would you recommend to carry 10 cumecs with a velocity of 1 mps?
Use 2:1 side slope and 15% freeboard.
2.12 m
Slope of the upstream face of the embankment
inside slope
Inside bottom or sill of the conduit.
invert
Closed conduit designed to convey canal water in full and under pressure running condition, to
convey canal water by gravity under roadways, railways, drainage channels and local depressions.
inverted siphon
__________ water requirement is the amount of water required in lowland rice production which
includes water losses through evaporation, seepage, percolation and land soaking.
land preparation
_________ water requirement is the amount of water required in lowland rice production which is
a function of the initial soil moisture and the physical properties of the soil.
Land soaking
Spacing between irrigation laterals.
Lateral spacing
Deep percolation of water beyond the root zone of plants, resulting in loss of salts or nutrients.
Leaching
Canal with impermeable material (usually concrete) for channel stabilization and/or reduced
seepage.
Lined canal
Allowable pollutant-loading limit per unit of time, which the wastewater generator is permitted to
discharge into any receiving body of water or land.
Loading limit
Portion of the pipe network between the mainline and the laterals.
Manifold
Spillway which is not excavated such as natural draw, saddle or drainage way.
Natural spillway
Constant flow depth along a longitudinal section of a channel under a uniform flow condition.
Normal depth
Maximum elevation of the water surface which can be attained by the spillway-type dam or
reservoir without flow in the spillway.
normal storage
Maximum elevation of the water surface which can be attained in an open channel without
reaching the freeboard.
Design depth
In what condition is the open channel freeboard used for water conveyance?
Inundation
The primary purpose in limiting water flow not to go below minimum velocity.
Avoid sedimentation
Open channel flow is water flow that is conveyed in such a manner that top surface is exposed to
the atmosphere such as flow in canals, ditches, drainage channels, culverts, and pipes under
_____ flow conditions.
Partially full
Part of the system that impounds the runoff.
Reservoir
Slope at the downstream face of the embankment.
Outside slope
Ratio between reference evapotranspiration and water loss by evaporation from an open water
surface of a pan.
Pan coefficient
Rate of water loss by evaporation from an open water surface of a pan.
Pan evaporation
Vertical flow of water below the root zone which is affected by soil structure, texture, bulk
density, mineralogy, organic matter content, salt type and concentration
Percolation
Vertical flow of water to carry salts contained in water.
Leaching
Method to determine the rate of flow under laminar flow conditions through a unit cross sectional
area of soil under unit hydraulic gradient.
Permeability test
The process by which the soil is removed from its natural place.
Soil erosion
A kind of terrace which consists of a series of flattened areas
Bench terrace
The practice where legumes are plowed or incorporated into the soil
Green manuring
Farming practice where plowing and harrowing are done along the contour.
Contouring
The simplest method of determining soil erosion over a period of time.
Pin method
Advanced form of erosion.
Gully erosion
Dam which resists water flow of water by its weight.
Gravity dam
Dam consisting of stones enclosed in cyclone wires which allows water passage.
Gabion dam
Material used to cover the soil to minimize evapotranspiration.
Mulch
Geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually
carbonate rocks such as limestone or dolomite.
Karst topography
Scientific name of carabao grass commonly used in vegetated open channels
Paspalum conjugatum
Philippine geographical constant for determining terrace vertical interval
0.5
Constant for soil erodibility and cover conditions for erodible soil and poor cover.
1
Estimate the peak runoff rate from a 20-hectare drainage basin if rainfall depth for 6 hours
reached 60 mm. Use typical runoff coefficient of 0.35.
0.2 cms
I = 60 mm/6 hrs = 10 mm/hr
q = 0.0028 CIA = 0.0028 (0.35)(10 mm/hr)(20 has) = 0.2 cms
Estimate the runoff volume from a 20-hectare drainage basin if rainfall depth for 6 hours
reached 60 mm and duration of runoff is about 3 hours. Use typical runoff coefficient of
0.35.
1,080 cms
A trapezoidal concrete gravity dam has vertical upstream wall. Water depth in the upstream
side is 50 meters above the dam base. Freeboard of 15% based on design depth. What is the
force of water exerted against dam per meter of dam width at deepest section?
1,250 tonnes
P = 0.5 x Water density x H2 = 0.5 x1 tonne/m3
x (50 m)2 = 1,250 tonnes
A trapezoidal concrete gravity dam has vertical upstream wall. Water depth in the upstream
side is 50 meters above the dam base. The base of dam is 78 meters along water flow. What
is the uplift force of seepage water below the dam per meter of dam width at deepest section?
1,950 tonnes
U = 0.5 x Water density x H x B = 0.5 x 1 tonne/m3
x 50m x 78m = 1,950 tonnes
A trapezoidal concrete gravity dam has inclined upstream wall. Resisting moment relative to
the dam toe is 263,953.2 tonne-meters while overturning moment is 96,233.3 tonne-meters
per meter of dam width at deepest section. What is the safety factor against overturning? Is it
safe?
2.74, safe
FSo = RM/OM = 263953.2/96233.3 = 2.74
Based on PhilMech’s 2011 and 2012 agricultural statistics of Asian countries, the Philippine
farm mechanization showed an upswing trend which recorded an average mechanization
level of 1.23 hp/ha; rice and corn farms registered the highest level of available farm power
at 2.31 hp/ha (Philippine Official Gazette, 2013). For the Philippines to level up with Japan,
the leader in Asia, agricultural and biosystems engineers should know Japan’s statistics.
What was the average level of farm mechanization in Japan as of 2012?
7 hp/ha
Based on the agricultural statistics survey of PhilMech in 2011 and 2012, ____ percent of the
total farm power is available for use in production operations while the remaining percentage
is used for postharvest operations.
70
An applied science that is concerned with quantitative decision problems that generally
involve the allocation and control of limited resources (IEOR-Columbia, 2022)
Operations research
You are the project engineer of an ABE company having a project involving 3 constraints, 5
stages and 18 locations. To minimize project duration, which technique will you use?
PERT/CPM
The equivalence of ln e^(y+z)/2
.
0.5(y+z)
From the rules on natural logarithm, ln e
^x = x
ln e(y+z)/2 = (x+y)/2
= 0.5(x+y)
The factorial of 10 less factorial of 9.
3,265,920
10! - 9! = 3,628,800 – 362,880
= 3,265,920
In an experiment, the total degrees of freedom increase as ___________ increases.
Replication
In a rice yield experiment, pre-experiment data shows varying soil fertility in the field. What
experimental design should be used such that the effects of blocking can be determined?
RCBD
A ranch is composed of 2,500 heads of Holstein-Friesian and 7,500 heads of Brown Swiss
cattle. Thirty representative heads are to be selected at random for use in an experiment. What
is the probability that a Brown Swiss will be randomly picked up at first selection?
75%
Probability = Number of heads of Brown Swiss / Total Number of Heads x 100%
= 7,500 / (2,500+7,500) x 100%
= 75%
A single-factor experiment using completely randomized experimental design results to the
following statistical values: treatment sum of squares of 2,510.5, error mean square error of
13.4, error degrees of freedom of 12 and total degrees of freedom of 14. How many treatments
are involved?
3
Tr DF = Total DF – Error DF = 14-12 = 2
No. of treatments = Tr DF + 1 = 2+1 = 3
In random sampling for the location of different treatments in the field, the labels for
Treatments 1, 2, 3, 4 and 5 were placed inside a box. Treatment 3 came out in the first pick.
What is the probability that you can pick Treatment 1 in the second pick?
25%
Probability = 1/No. of Treatments Left Unpicked = 1/(5-1) = 0.25 = 25%
The return period of a flood stage of 5 meters or more is 2 years. What is the probability that
this event will be reached next year?
50%
Probability = 1/ return Period = ½ = 0.5 = 50%
In Analysis of Variance, what is the F value of an experiment having treatment sum of
squares of 2,510.5, error mean square error of 13.4, treatment degrees of freedom of 2 and
error degrees of freedom of 12?
93.68
Tr MS = TrSS/Tr DF = 2510.5/2 = 1255.25
F = Tr MS/MSE = 1255.25/13.4 = 93.68
You need to present a graph of x values vs. y values. The x values are 0, 1, 2, 3, 4 and 5. The
y values are ln 0, ln 1, ln 2, ln 3, ln 4 and ln 5, respectively. Since ln 0 results to a
mathematical error, what value will you use for ln 0? Use 2 decimal places in your
computations
-4.61
In a regression equation Y = 2.5 + 3X, where X is the flood stage in meters at a certain
location and Y is the estimated amount in million Php of damaged crops downstream. If
flood stage is 20 meters, what is the estimated amount of damaged crops in million Php?
62.5
Y = 2.5 + 3X
= 2.5 + 3(20)
= Php62.5 million
Per Department of Agriculture Administrative Order No. 4, series of 2022, the minimum
inorganic fertilizer rates should be ___ bags/hectare (3 bags urea plus three bags 14-14-14 or
three bags urea plus two bags 16-20-0 and one bag 0-0-60)
6
Per BFAR standard, the intensive stocking density of tilapia is __ heads per square meter.
> 8
Intensive fish stocking density needs _________ feedS
Commercial
Per BFAR standard, the extensive stocking density of tilapia is __ heads per square meter.
3
Tilapia fingerlings need feeds equivalent to ____% of body weight.
10-15
Tilapia feeding frequency
2-3 times daily
A marketable size tilapia weighs ___ grams/head.
> 91
Tilapia fry needs feeds equivalent to ____% of body weight.
15-30
How many mango seedlings are needed to be purchased for 1 hectare area if the planting
density is 10 meters by 10 meters. Give 5% allowance in the number of seedlings purchased.
105
No. of Seedlings = Safety Factor [Area in ha x 10,000 m2
/ha / Planting Density in m x m]
= 1.05 [1 ha x 10,000 m2
/ha / (10 m x 10 m)]
= 105 seedlings/hectare
If the recommended rate of nitrogen is 90 kg/hectare, how many kilograms of urea fertilizer
are to be applied per hectare using 46-0-0 urea fertilizer alone?
196
Fertilizer rate = (Rate of Desired Nutrient x 100) / Percentage of the Nutrient in the Fertilizer
= (90 kg/ha x 100) / 46
= 195.65 kg/ha
Based on the experimental field’s soil analysis, the recommended fertilization rate for P2O5 is 45
kg/ha. What should be the fertilization application rate of P2O5 in kilograms/hectare if using 0-22-0
fertilizer alone?
205
Fertilizer rate = (Rate of Desired Nutrient x 100) / % of the Nutrient in the Fertilizer
= (45 kg/ha x 100) / 22
= 204.5 kg/ha
Based on the farm’s soil analysis, the recommended fertilization rate for K2O is 16.8 kg/ha. What
should be the weight per unit area in kilograms/hectare of K2O to be applied if using 0-0-60 fertilizer
alone?
28
Fertilizer rate = (Rate of Desired Nutrient x 100) / % of the Nutrient in the Fertilizer
= (16.8 kg/ha x 100) / 60
= 28 kg/ha
If the recommended rate of nitrogen is 90 kg/hectare, how many bags of urea fertilizer are
needed per hectare using 46-0-0 urea containing 50 kilograms per bag?
196
Fertilizer rate = (Rate of Desired Nutrient x 100) / % of the Nutrient in the Fertilizer
= (90 kg/ha x 100) / 46
= 195.65 kg/ha
No. of Bags = Fertilizer Requirement in kg/hectare / No. of Kilograms Contained per Bag
= 195.56 kg/ha / 50 kg/bag
= 3.91 bags/ha, round up to 4 bags/ha
If tilapia stocking relies only on natural food source, how many tilapia fingerlings should be
stocked in each of 50 experimental cages, each cage has a diameter of 1 meter and depth of 1
meter? Mortality safety factor is 7% for small cages.
3
Tilapia extensive stocking density (relies only on natural food source): 3 heads/m2
Area of cage = 3.14 (1 m)2
/4 = 0.785 m2
Stocks = Density x Area x [1+ safety factor in ratio] = 3 x 0.785 x (1.07) = 3 heads/cage
