Surface Irrigation Methods

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What is the head 'h' in a weir equivalent to?

One half of the total depth of water over the crest of the weir (correct)
One quarter of the total depth of water over the crest of the weir
The total depth of water over the crest of the weir
Three quarters of the total depth of water over the crest of the weir

What is the purpose of a weir in an open channel?

To increase the flow rate
To control and raise the water level slightly on the upstream side (correct)
To reduce the water level on the upstream side
To prevent evaporation

What is the characteristic of a rectangular weir with end contractions?

The effective length of crest increases by 0.20H
The effective length of crest remains the same
The effective length of crest decreases by 0.20H (correct)
The effective length of crest is zero

Who invented the trapezoidal or Cipolletti weir?

An Italian engineer (B) Signup and view all the answers

What is the side slope of a trapezoidal or Cipolletti weir?

1 horizontal to 4 vertical (B) Signup and view all the answers

What type of equation can be used to derive the flow of water over a weir?

Energy equation (D) Signup and view all the answers

What is the primary benefit of furrow irrigation over border flooding?

Furrow irrigation is more adaptable to closely spaced row crops (A) Signup and view all the answers

What is a key characteristic of corrugation irrigation?

It is adaptable to closely spaced row crops (C) Signup and view all the answers

What is the primary function of an emitter in trickle or drip irrigation?

To deliver water directly to the soil near the plant (A) Signup and view all the answers

What is a key advantage of sprinkler irrigation?

It simulates natural rainfall (D) Signup and view all the answers

What is a key characteristic of sub-surface irrigation?

It is suitable for areas with favorable natural soil and topographic conditions (A) Signup and view all the answers

What is the primary difference between furrow irrigation and corrugation irrigation?

Corrugation irrigation uses smaller channels than furrow irrigation (B) Signup and view all the answers

What is the primary function of a control head in sprinkler irrigation?

To regulate water pressure in the pipes (C) Signup and view all the answers

What is a key benefit of trickle or drip irrigation?

It reduces water evaporation and runoff (C) Signup and view all the answers

What is the primary function of a hydraulic ram?

To pump water powered by falling water (C) Signup and view all the answers

What is a closed conduit?

A type of channel where water is supplied through pipelines (A) Signup and view all the answers

What is one of the positive impacts of irrigation on health?

Ensuring household food security and improving nutrition (C) Signup and view all the answers

What is one of the negative impacts of irrigation on the environment?

Reducing the flow of water at downstream needed to sustain natural ecosystem (D) Signup and view all the answers

What is one of the negative impacts of irrigation on socioeconomic conditions?

Depriving downstream users of their water (C) Signup and view all the answers

What is one of the causes of water quality degradation?

Inappropriate use of inputs such as fertilizer, pesticides, and herbicide (C) Signup and view all the answers

What is the purpose of a Parshall flume?

To measure the flow rate of water (C) Signup and view all the answers

What is one of the positive impacts of irrigation on agriculture?

Increasing agricultural production (C) Signup and view all the answers

What is the main advantage of a triangular or V-notch weir in measuring small water flow in canals?

It provides accurate flow measurements (A) Signup and view all the answers

What is a common issue with using weirs in water measurement?

Deposition of gravel, sand, and silt on the base of the weir (A) Signup and view all the answers

What is the main difference between a cutthroat flume and a Parshall flume?

The shape of the flume's throat section (B) Signup and view all the answers

What is the advantage of using a Type H flume in measuring stream flow?

It provides high accuracy at low flows (C) Signup and view all the answers

What is the main advantage of pump irrigation over gravity irrigation?

It allows for independence and control over water supply (C) Signup and view all the answers

What is the principle of operation of a jet pump?

It uses a high-pressure fluid jet and the venturi effect (A) Signup and view all the answers

What is the main characteristic of a roto-dynamic pump?

It has a rotating element that imparts energy to the water (A) Signup and view all the answers

What is the main difference between a displacement pump and a roto-dynamic pump?

The way they impart energy to the water (A) Signup and view all the answers

What is the primary source of nitrate concentration in groundwater, according to the text?

Urea fertilizer (A) Signup and view all the answers

What is the impact of drainage flows from irrigated fields on the ecosystem?

They disturb the ecological balance by carrying excess chemical nutrients and pollutants (D) Signup and view all the answers

What is the economic consequence of using poor quality or contaminated water for drinking and other uses?

It has an impact on the economical aspects of other activities such as industrial, tourism, and fishery (B) Signup and view all the answers

What is the result of unplanned and excessive groundwater abstraction for irrigation?

It causes the decline of the initially shallow water table (A) Signup and view all the answers

What is the consequence of a lowered water table on vegetation?

It causes vegetation to die off (D) Signup and view all the answers

What is the impact of unplanned and excessive groundwater abstraction on natural springs and ponds?

It leads to the drying up of natural springs and ponds (C) Signup and view all the answers

What is the economic consequence of rectifying polluted water quality?

It requires expensive and long-term investments (A) Signup and view all the answers

What is the impact of water quality degradation on human health?

It leads to cyanosis syndromes and carcinogenic impacts (D) Signup and view all the answers