The correct answer is Kuhl systems (traditional channels).
Kuhl systems are a traditional form of irrigation that is commonly used in the hilly terrain of Himachal Pradesh. They are a type of gravity-fed irrigation system that uses channels to carry water from a source, such as a stream or a river, to the fields that need to be irrigated. Kuhl systems are very efficient in terms of water use, and they are also relatively low-cost to construct and maintain.
Drip irrigation is a type of irrigation that delivers water directly to the roots of plants, usually through a network of small pipes or tubes. Drip irrigation is very efficient in terms of water use, and it can also help to reduce the risk of waterlogging and soil erosion. However, drip irrigation systems can be relatively expensive to install and maintain.
Sprinkler irrigation is a type of irrigation that uses sprinklers to spray water over the crops. Sprinkler irrigation is a relatively efficient way to irrigate large areas, but it can be wasteful of water if the sprinklers are not properly adjusted. Sprinkler irrigation can also lead to waterlogging and soil erosion.
Flood irrigation is a type of irrigation that involves flooding the fields with water. Flood irrigation is a very simple and inexpensive way to irrigate crops, but it is also very wasteful of water. Flood irrigation can also lead to waterlogging and soil erosion.
In conclusion, Kuhl systems are the most commonly used type of irrigation in the hilly terrain of Himachal Pradesh. They are a traditional form of irrigation that is very efficient in terms of water use.