The fertile earth also needs water to give utmost making of yield. The usual foundation of irrigation for crops is rain, but rain does not drop all over every year. There are regions in Pakistan,
where there is short rainfall, therefore, in such places fake methods of irrigation are adopted. Such methods are:-
Dams. Canals. Wells. Tanks and Embankments. Karez.
DAMS. In Pakistan Mountains recline in the north. So, when snow dissolves on mountains, water flows from north to south in the form of rivers, brooks, and even forms a lagoon. On these rivers, streams and lakes, dams are bring built to take out canals. Canals are being taken out for irrigation reasons. There are fifteen, big and small dams in Pakistan. In Pakistan five main rivers run from northern mountain array to south in the ocean. Along their path, diverse dams, barrages have been built to take out canals for irrigation purpose. The irrigation classification of Pakistan is amongst the finest in the world. The following feature shows the figure of canals taken out of the rivers during dams and barrages. Barrages are small dams. The major rivers of Pakistan are: (i) Sutlej. (ii) Jhelum. (iii) Ravi. (iv) Chenab. (v) Indus.
CANALS. There are different kinds of canals :- ( i ) Perennial canals. ( ii ) Non-Perennial canals. (iii ) Inundation canals. ( iv ) Link canals.
Wells. The rain water is engrossed in the higher supple soil of the earth. Under the floor there are firm rocks which cannot attract water. As a result a large number of water is stored on the facade of the underground hard rocks. Wells are dug to use this water for agricultural purpose. There are two kinds of wells. ( i ) Persian wells. ( ii ) Tube wells.
Persian Wells. These kinds of wells are mostly found in those areas where water does not lie in depths. A big hole is dug about 10 feet wide and 30 to 60 feet deep in land. Water gathers in the fissure, from where it is taken out with the help of Persian wheels. There are small barrels hanged with the Persian wheel. A spinning wheel is attached to this Persian wheel, which is pulled by a squad of cows or other animals.
Tube Wells. These kinds of wells are frequently found where water is in great deepness. Water is taken out of the tube wells with the help of electric motors, diesel engines and tractors. These kinds of means of irrigation bring water from huge depths.
Tanks and Embankments. These kinds of irrigation method are adopted in regions where there are very few rainfalls. In order to store rain water, Big tanks have been constructed at some places in plains. Stored water is used in dry seasons. In mountain areas of fewer height, embankments have been built on rivulets to store water. The stored water is channeled into canals and streams to irrigate the fields.
Karez. This kind of irrigation method is adopted where climate is dry and very hot. People build short tunnels from baked bricks around canals.
These tunnels carry water from mountains to fields for irrigation purposes. Karez are mostly found in Baluchistan where it is very hot. Karez carry water beneath the ground to keep away from the defeat of water by vanishing.