Lecture 12

Question 1

a technology used for collecting and storing
rainwater for human

Answer 1

Rainwater Harvesting

Question 2

Rainwater harvesting has
been practiced for more than _____

Answer 2

4000 years

Question 3

defined as the method for inducing,
collecting, storing and conserving local surface runoff for agriculture in arid and semi-arid
regions.

Answer 3

Rainwater Harvesting

Question 4

method of collecting surface runoff from a
small catchment area and storing it in the root zone of an adjacent infiltration basin.
The basin is planted with a tree, a bush or with annual crops.

Answer 4

Micro-catchement water harvesting

Question 5

also called harvesting from external catchments is
the case where runoff from hill-slope catchments is conveyed to the cropping area
located at foothill on flat terrain.

Answer 5

Macro-catchment water harvesting

Question 6

defined as the collection and storage
of creek flow for irrigation use.

Answer 6

Flood water harvesting

Question 7

Also known as large catchment water harvesting or Spate irrigation

Answer 7

Flood water harvesting

Question 8

The water flow is dammed and as a result, inundates the valley bottom of the flood plain. The water is forced to
infiltrate and the wetted area can be used for agriculture or pasture improvement.

Answer 8

Flood water harvesting within stream bed

Question 9

The wadi water is forced to leave its natural course and conveyed to nearby cropping field

Answer 9

Flood water diversion

Question 10

new term and employed to
cover traditional as well as unconventional ways of ground water extraction.

Answer 10

Groundwater harvesting

Question 11

Examoles of groundwater hatvesting techniques

Answer 11

Qanat system,
underground dams
Special types of wells

Question 12

Fine examples of groundwater harvesting

Answer 12

Subsurface dams
Sand storage dams

Question 13

includes runoff harvesting, flood water harvesting and groundwater harvesting.

Answer 13

Water harvesting techniques

Question 14

This method involves the construction of bunds on the contour of the
catchment area

Answer 14

Contour bunds

Question 15

These bunds hold the flowing surface runoff in the area located
between two adjacent bunds.

Answer 15

Contour bunds

Question 16

The height of contour bund generally ranges from

Answer 16

0.30 m to 1.0 m

Question 17

Length of contour bunds

Answer 17

10 to a few 100 m

Question 18

This type of structure consists of an earthen impartment constructed in
the shape of a semicircle

Answer 18

Semicircular hoop

Question 19

Height of hoops

Answer 19

0.1 to 0 .5m

Question 20

Radius of the hoop

Answer 20

5 to 30 m

Question 21

Such bunds also consist of an earthen embankment, constructed in the
shape of trapezoids.

Answer 21

Trapezoidal bunds

Question 22

also referred as off contour bunds. They consist of earthen or
stone embankments and are constructed on a land with a slope range of 0.5 to 2%

Answer 22

Graded bunds

Question 23

Slope for graded bunds

Answer 23

0.5 to 2%

Question 24

Height of graded bunds ranges from

Answer 24

0.3 to 0.6 m

Question 25

are the exposed rock surfaces, used for collecting the
runoff water in a part as depressed area.

Answer 25

Rock catchment

Question 26

Area of rock carchment

Answer 26

100 m² to 1000 m²

Question 27

large area of ground is used as catchment for runoff
yield.

Answer 27

Ground catchment

Question 28

Also called roaded catchment

Answer 28

Ground catchment

Question 29

constructed by excavating the soil from the ground
surface. These ponds may be fed by ground water or surface runoff or by both

Answer 29

Dugout ponds

Question 30

Land slope needed in dugout ponds ___ and depth from groundwater surface ____

Answer 30

4% and 1.5-2 m

Question 31

These types of reservoirs are constructed by forming a dam
or embankment on the valley or depression of the catchment area

Answer 31

Embankment type reservoir

Question 32

mainly meant to store the surface water for
irrigating the crops. The capacity is decided based on the amount of input water available
and output water desired.

Answer 32

Irrigation dam

Question 33

detain the silt load coming
along with the runoff water from the catchment area and simultaneously to harvest water.

Answer 33

Silt detention dam

Question 34

Such dams are located at the head of the valley to form the shape of a
water tank or pond

Answer 34

High level dam

Question 35

constructed for multi-purpose objectives, such as for irrigation,
live-stock, water supply to the cattle feed, fish production etc.

Answer 35

Farm pond

Question 36

These dams are generally constructed at the valley head, without the
provision of checking the percolation loss.

Answer 36

Percolation dam

Question 37

These are long low rock dams across valleys slowing and spreading floodwater as well as
healing gullies

Answer 37

Permeable rock dams

Question 38

this method, runoff water is
diverted to the area covered by graded bund by constructing diversion structures such as
diversion drains.

Answer 38

Water spreading bunds

Question 39

The reservoirs constructed at suitable sites for controlling the flood
are known as flood control reservoirs. They are well equipped with self-operating
mechanical outlets for letting out the harvested water into the stream or canal below the
reservoir as per requirement.

Answer 39

Flood control reservoir

Question 40

consists of a long tunnel or conduit leading from a well dug at a
reliable source of groundwater (the mother well)

Answer 40

Qanat systems