Water Supply Midterms: Module 4

The process of a seed starting to grow, or the act of causing a seed to start growing

Three basic requirements of agricultural production

Additional requirements of agricultural production

most important requirement of agricultural production.

The artificial application of water to land for supplementing the naturally available moisture in the root-zone soil for the purpose of agricultural production is

Applications of water in soil

Two categories of irrigation schemes

Use diversion and storage methods and obtain their supplies from rivers.

Use open wells, and deep and shallow tube wells to lift water from the water-bearing strata below the earth’s surface

Factors to be considered in irrigation systems

Traditional Methods of Irrigation

Also known as Moat. During this method, water is directly collected from the well, using a pulley to irrigate fields.

It consists of two large wheels connected with an endless chain. The bottom wheel is half immersed in the water source. With the turning of the wheel, the connected buckets dip into the water source and bring water. Chain lifts them to the upper wheel where water from the bucket is transferred to the pool.

During this system, a rope and bucket is connected to a pole or heavy stick to obtain water from the well. It is also connected to a heavy counterweight at the other end to draw water.

During this method, water is drawn from the well through a wheel connected to animals like cows, buffalo, oxen, etc. With the movement of animals, wheels rotate and it draws the water from the well.

Modern Methods of Irrigation

is a method of laying out the water channels in such a way where gravity plays the role of providing just enough water for suitable plants to grow. It is usually made by the planned placement of ridges and furrows. It is a kind of surface irrigation system.

is the most common form of surface irrigation, particularly in regions with layouts of small fields. If a field is level in all directions, encompassed by a dyke to prevent runoff and provides an undirected flow of water onto the field, it is referred to as basin. (Stauffer & Spuhler 2012)

Mimic the phenomenon of rain. The pipes carry water to central locations on the farm. Is one of the most efficient irrigation methods to irrigate the uneven land for agriculture.

we lay plastic pipes in rows near the crops or plants. These pipes have holes in them. The water seeps from these holes drop by drop, hence the name

Specific Function of Irrigation System

e is built at the entry to the irrigation system. Its purpose is to direct water from the original source of supply (lake, river, reservoir etc.) into the irrigation system.

In some cases, the irrigation water source lies below the level of the irrigated fields. Then it must be used to supply water to the irrigation system

consist of canals transporting the water through the whole irrigation system.

are required for the control and measurement of the water flow.

or ditch, is an open waterway whose purpose is to carry water from one place to another.

refer to main waterways supplying water to one or more farms.

have smaller dimensions.

Canal Characteristics

are simply dug in the ground and the bank is made up from the removed earth

Earthen canals that are lined with impermeable materials to prevent excessive seepage and growth of weeds

four main types of canal structures

are required to reduce the bottom slope of canals lying on steeply sloping land in order to avoid high velocity of the flow and risk of erosion.

are used to divide or direct the flow of water between two or more canals or ditches.

are constructed in the bank of a canal. They divert part of the water from the canal to a smaller one.

are used to divert water from the field ditch to the field, it is often necessary to raise the water level in the ditch.

used to carry irrigation water across roads, hillsides and natural depressions.

are used to carry the water across roads.

is used instead of a culvert when water has to be carried across a road which is at the same level as or below the canal bottom

its main objective is to permit efficient distribution and application.

consists of a wall of timber, metal or concrete with an opening with fixed dimensions cut in its edge

consists of a metal or concrete channel structure with three main sections

is similar to the Parshall flume, but has no throat section, only converging and diverging sections

is necessary to remove excess water from the irrigated land. This excess water may be e.g. waste water from irrigation or surface runoff from rainfall. It may also include leakage or seepage water from the distribution system.

Excess surface water is removed through

Excess groundwater is removed through