Month: July 2020

Determine the Discharge of the Channel for which it is to be Designed

Mathematical Problem

A channel is to be designed for irrigating 6000 hectares of Kharif crop and 5500 hectares of Rabi crop. The water requirement for the Kharif crop is 70 cm and the water requirement for Rabi is 35 cm. The Kor period for Kharif is 2 weeks and for Rabi is 3 weeks and 4 days. Determine the discharge of the channel for which it is to be designed.

Solution:

Using the relation

∇ = (8.64 × B)/ D

Discharge for Kharif crop

Here,

∇ = 70 cm = 0.70 m
B = 2 weeks = 14 days

Duty (D) = (8.64 × 21)/ 0.70 = 259.2 hectares/cumec.

Area to be irrigated = 6000 hectares.

Required discharge of channel for Kharif crop = (6000/259.2) = 23.15 cumec.

Discharge for Rabi crop

Here,

∇ = 35 cm = 0.35 m.
B = 3 weeks and 4 day = (21 + 4) = 25 days.

Duty (D) = (8.64 × 25)/ 0.35 = 617.14 hectares/cumec.

Area to be irrigated = 5500 hectares.

Required discharge of channel for Kharif crop = (5500/617.14) = 8.91 cumec.

Therefore, the channel is to be designed for the maximum discharge of 23.15 cumec, because this discharge capacity of the channel will be able to supply water to both seasons.

Read More:

Relation Between Base, Delta, and Duty

Factors Affecting the Duty of Water

How to Calculate Discharge of The Water If The Depth & Crop Period are Given

Mathematical Problem

A Waterhouse has a culturable commanded area of 2200 hectares. The intensity of irrigation for crop A is 50% and for B is 35%, both the crops being Rabi crops. Crop A and B have a crop period of 25 days and 20 days respectively. Calculate the discharge of the water if the depth for crops A and B is 12 cm and 18 cm respectively.

Solution:

Culturable land for irrigation = 2200 hectares.

Area of irrigation for Crop A = 2200 × 50% = (2200 × 50)/100 = 1100 hectares.

Area of irrigation for Crop B = 2200 × 35% = (2200 × 35)/100 = 770 hectares.

Using the relation.

D = (8.64 × B)/ ∇

Discharge for crop A

Here,

∇ = 12 cm = 0.12 m.
B = 25 days

Duty (D) = (8.64 × 25)/0.12 = 1800 hectares/cumec.

Required discharge for crop A = (1100/1800) = 0.61 cumec.

Discharge for crop B

Here,

∇ = 18 cm = 0.18 m
B = 20 days

Duty (D) = (8.64 × 20)/0.18 = 960 hectares/cumec.

Required discharge for crop B = ( 770/960) = 0.80 cumec.

S0, the total discharge of water course = (0.61 + 0.80) = 1.41 cumec.

Read More:

Relation Between Base, Delta, and Duty

Factors Affecting the Duty of Water

Determine the Discharge of the Channel for which it is to be Designed

How to Calculate Annual Runoff? Problem & Solution

How to Calculate Annual Runoff?

Mathematical Problem:

For a catchment in M.P., India, the mean monthly rainfall and temperatures are given. Calculate the annual runoff by Khosla’s formula.

Month	Jan	Feb	Mar	Apr	May	June	July	Aug	Sep	Oct	Nov	Dec
Temp (°C)	12	16	21	27	31	34	31	29	28	29	19	14
Rainfall	4	4	2	0	2	12	32	29	16	2	1	2

Solution:

In Khosla’s formula,

R_m = P_m – L_m

Where,

R_m = Monthly runoff
P_m = Monthly rainfall in cm
L_m = (0.48 × T) Or P_m whichever is less.
T = Monthly temperature in degrees.

1. For January month

L_m = (0.48 × 12) = 5.76

So, 5.76 is greater than the corresponding P_m = 4.

So, the value of L_m will be taken as 4.

Now,

R_m = (P_m – L_m) = (4 – 4) = 0

2. For July month

L_m = (0.48 × 31) = 14.88

So, 14.88 is less than the corresponding value of P_m = 32

So, we will take the value of L_m = 14.9

Now,

R_m = (P_m – L_m) = (32 – 14.88) = 17.1

I think you can able to solve the rest of the months by using the above method.

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Rainfall (P_m)	4	4	2	0	2	12	32	29	16	2	1	2
Temp (°C)	12	16	21	27	31	34	31	29	28	29	19	14
L_m	4	4	2	0	2	12	14.9	13.9	13.4	2	1	2
R_m	0	0	0	0	0	0	17.1	15.1	2.6	0	0	0

So, the total annual runoff = ( 17.1 + 15.1 + 2.6) = 34.8 in cm.

Read More:

Types of Rainfall

Types of Irrigation

Methods of Improving Duty of Water

Hydrological Cycle and Rainfall – MCQ

1. An isohyet is a line joining point having

a) Equal evaporation value
b) Equal barometric pressure
c) Equal height above the MSL
d) Equal rainfall depth in a given duration

View Answer

d) Equal rainfall depth in a given duration

2. Water budget equation can be expressed as

a) Change in mass storage = mass outflow – mass inflow
b) Change in mass storage + mass outflow = mass inflow
c) Change in mass storage – mass outflow = mass inflow
d) Change in mass storage = mass inflow/mass outflow

View Answer

b) Change in mass storage + mass outflow = mass inflow

3. The catchment area of a river is bounded by

a) Contour line
b) Tributary of a river
c) Watershed line
d) None of these

View Answer

c) Watershed line

4. What type of rain gauge will you install in an inaccessible area during the rainy season

a) Symon type
b) Syphon type
c) Tipping bucket type
d) Weighing bucket type

View Answer

a) Symon type

5. A plot between rainfall intensity versus time is called as

a) Hydrograph
b) Mass curve
c) Hyetograph
d) Isohyet

View Answer

c) Hyetograph

6. The standard recording rain gauge adopted in India is of

a) Weighing bucket type
b) Natural siphon type
c) Tipping bucket type
d) Telemetry type

View Answer

c) Tipping bucket type

7. The hyetograph is a curve showing

a) Time vs. Accumulated rainfall
b) Time vs. Transpiration
c) Time vs. Intensity of rainfall
d) Time vs. Run-off from the catchment

View Answer

c) Time vs. Intensity of rainfall

8. The value of the run-off coefficient for commercial and industrial areas is

a) 0.3
b) 0.5
c) 0.9
d) None of these

View Answer

c) 0.9

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Water Demand – MCQ

Precipitation and its measurement – MCQ

5 Types of Rainfall

Importance of Highway Lighting – Highway Engineering

Importance of Highway Lighting

The rate of highway accidents and fatalities that occur during night driving is several times higher than that during daytime driving. To overcome this hazardous situation, highway lighting plays an important role. Following are some benefits and importance of highway lighting or street lighting.

1. Highway/street lighting enables road users mainly cyclists, pedestrians, bullock cart drivers, and motorists to see more accurately and easily the carriageway and its surrounding areas at night.

2. On a highway, all the vehicles have their own headlight, but it is not possible to fully depend on the headlights for night driving, if all vehicles are to drive with the full headlight on, the glare problem can cause a severe accident. Therefore, highway lighting is required to illuminate the carriageway and its surrounding.

3. Traffic flow conditions improve as the speed of traffic improves due to better lighting.

4. Due to the presence of traffic lights, the accident numbers at night time will be reduced.

5. There will be a reduction in highway crime at night.

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Highway Lighting – MCQ

6 Stopping Sight Distance Formula

Water Demand – MCQ || Water Supply Engineering

Water Demand – MCQ

Following are some question and answer about water demand:

1. Per capita demand is

a) Total yearly water requirement(litres) / 365 × Population
b) Total yearly water requirement(litres) / Design Population
c) Total yearly water requirement(litres) / Population
d) Total yearly water requirement(litres) / 365 × Design Population

View Answer

d) Total yearly water requirement(litres) / 365 * Design Population

2. The ratio of maximum daily demand to average demand is

a) 1.8
b) 1.2
c) 1.48
d) 2.7

View Answer

a) 1.8

4. The best method for forecasting the population of a new and fast-growing city is

a) Logistic method
b) Incremental increase method
c) Arithmetic increment method
d) Geometrical increase method

View Answer

d) Geometrical increase method

3. Water supply projects under normal circumstances are designed for periods of

a) 15 years
b) 20 years
c) 25 years
d) 30 years

View Answer

d) 30 years.

5. Maximum hourly consumption is generally taken as ______ percent of its average hourly consumption

a) 100
b) 150
c) 200
d) 250

View Answer

b) 150

6. Maximum hourly demand of the maximum day( i.e peak demand) is equal to

a) 1.5 × average hourly demand
b) 2.7 × annual average hourly demand
c) Both (a) and (b)
d) None of these

View Answer

c) Both (a) and (b)

7. The coincident draft is taken as

a) Maximum hourly demand + fire demand
b) Maximum hourly demand
c) Average daily demand + fire demand
d) Greater of (b) and (c)

View Answer

d) Greater of (b) and (c)

8. The unit of per capita demand is

a) litres/head/day
b) head/day
c) days/head/litres
d) None of these

View Answer

a) litres/head/day

Water Quality – MCQ

Sources of Water – MCQ

Safety Against Fire in Theatres and Cinemas

Cinema halls and theatres are such public buildings where people are gathered in very large numbers. If proper fire-resisting measures were not taken, loss of life may be very large in case of fire break out. The following are the measures that should be taken to make them fire-resistant:

1. Projector room and the room where the script is reminded should be made properly fire-resistant.

2. Safety lights play a very important role in case of fire break out. safety lights must be provided in all the rooms. Connection and operation of safety lights should be separated from the main lighting because, if the main light goes off due to fire, the safety lights can be turned on to facilitate clear visibility, so that occupants may escape safely.

3. All the passages and gangways should be centrally located and designed in suitable widths. They should also be rendered fireproof.

4. The escape doors and exit doors should be properly marked and illuminated so that they could be easily located even in darkness.

5. Suitable fire fighting appliances should be provided at all important locations and the staff should be trained to use them in case of fire.

6. Smoke detectors and fire alarms should be installed.

General Principle of Thermal Insulation

Roadside Development and Arboriculture – MCQ

1. What is the purpose of trees planting on the roadside

a) To act as wind breaker for the traffic
b) To stabilize the formation
c) To provide shade
d) All of these ✅

2. Arboriculture means _______

a) Tree culture ✅
b) Wood Culture
c) Apiculture
d) None of these

3. Roadside tree should demand ________ amount of water

a) high
b) medium
c) less ✅
d) very high

4. Spacing between two trees along the carriageway should be between ____ m to _____ m

a) 3 to 6 m
b) 5 to 8 m
c) 7 to 10 m
d) 9 to 12 m ✅

5. The operation of loosening soil around tree is known as

a) Hoeing ✅
b) Pruning
c) Lopping
d) Felling

6. Tree guards are provided for

a) Protecting young plant
b) Defending from animal
c) All of these ✅
d) None of these

7. Which process is useful for making a tree grow straight and dense

a) Hoeing
b) Pruning ✅
c) Felling
d) None of these

8. The tree should be planted _______ m away from the centre of the carriageway

a) At least 20
b) At least 16
c) At least 12 ✅
d) At least 8

9. Arjun trees are suitable for

a) Sandy soil
b) Loamy soil ✅
c) Clayey soil
d) None of these

Read More:

Rules for Roadside Tree Planting

Roadside Development and Arboriculture

Types of Road Pavement

What are the Advantages of Thermal Insulation?

Advantages of Thermal Insulation

Thermal insulation offers several advantages, making it an important aspect of any building project. Here are some key advantages of thermal insulation:

1. Comfort to the Occupants

Thermally insulated buildings or rooms remain cool in summer and warm in winter than outside. This results in comfortable conditions for the occupants, inside the building.

2. Power Saving

In very cold countries(like; Russia, Canada, USA, and Sweden), central or other systems of heating are installed to keep warmer conditions inside the buildings. Similarly in hot countries(like India, Sri Lanka, Australia, Pakistan, Bangladesh, Kenya, etc.), air conditioning is required to maintain the desired temperature inside the buildings.

Both heating and air conditioning involve the expenditure of energy. Due to thermal insulation, require less consumption of energy to maintain the desired temperature inside the building.

3. Condensation

The provision of thermal insulating materials inside a room prevents condensation on interior walls and ceilings. Condensation is the deposition of moisture and it takes place when warm air comes into contact with surfaces having a temperature below the dew point.

Condensation is harmful in some of the manufacturing processes. If condensation is the outcome of the manufacturing process, the humidity may be reduced by passing air through a humidifier.

4. Water System

The use of thermal insulating materials reduces the risk of water freezing in winter, and loss of heat in the case of a hot water system.

5. Cost Savings

Investing in thermal insulation can result in long-term cost savings. Although initial installation costs may be high, the energy savings achieved through lower heating and cooling expenses can quickly offset these costs.

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General Principle of Thermal Insulation

5 Characteristics of Fire Resisting Materials

General Principles of Thermal Insulation

The following are the general principles of thermal insulation:

1. More thermally insulated materials should be used in the construction of buildings.

2. The building should be constructed in such a way that the minimum of its area is exposed to direct sun.

3. The building should be oriented in such a way that the transfer of solar energy should be maximum in winter and minimum in summer.

4. The chajja over the doors and windows should be provided because it helps to reduce the direct effects of winds and solar energy. Direct effects of winds can also be reduced by providing Verandah on the side of the wind direction.

5. The thermal resistance of insulating material is directly proportional to its thickness and hence sufficient thickness of the material should be installed.

6. The arrangement of air gaps in the outer exposed walls proves to be a very effective measure for structural thermal insulation.

Read More:

Orientation of Building

Characteristics of Fire-Resisting Materials