Wednesday, 28 June 2017

Indus Basin Project

Indus Basin Project Points : indus basin project, history of indus basin irrigation system HISTORY OF INDUS BASIN IRRIGATION SYSTEM 1. Controlled year round irrigation began in 1859 with the completion of the Upper Bari Doab Canal (UBDC) from Madhopur Head works (now in India) on Ravi River. Until that time, irrigation was undertaken through a network of inundation canals, which were functional only during periods of high river flow. These provided water for kharif (summer) crops and some soil moisture for rabi (winter) crops.

2. The last inundation canals were connected to weir controlled supplies in 1962 with the completion of Guddu Barrage on Indus River. UBDC was followed by Sirhind Canal from Rupar Headworks on Sutlej in 1872 (also in India) and Sidhnai Canal from Sidhnai Barrage on Ravi in 1886. The Lower Chenab from Khanki on Chenab in 1892, and Lower jhelum from Rasul on Jhelum in 1901 followed suit. Lower and Upper Swat, Kabul River and Paharpur Canals in NWFP were completed between 1885 to 1914.

Thursday, 4 May 2017

Storage Irrigation - Short Questions and Answers

Storage Irrigation - Short Questions and Answers Points : storage irrigation short questions and answers Q.1: What is storage irrigation? Ans: In storage irrigation system, a solid barrier, such as a dam or a storage weir is constructed across the river and water is stored in the reservoir or lake so formed. Q.2: Write down the different components which storage Irrigation Is depended. Ans: Depending upon the water requirements of crops, or the hydroelectric power generation, and upon the flow of water in the river, the volume of storage required is decided.

Storage Irrigation

Storage Irrigation Points : Storage Irrigation, Methods of Assessment of run off from a catchment area, Basin Recharge, Direct Run-off, In storage irrigation system, a solid barrier, such as a darn or a storage weir is constructed across the river and water is stored in the reservoir or lake so formed. Depending upon the water requirements of crops, or the hydroelectric power generation, and upon the flow of water in the river, the volume of storage required is decided. From the contour plan of the basin at the site of construction, the elevation storage curve for the reservoir is known. The height of the dam is then decided from this curve, corresponding to the storage-volume required. In Pakistan, most of the irrigation schemes fall under this category. Fig. shows the schematic plan for such a scheme.

Saturday, 22 April 2017

Maintenance of Canals

Maintenance of Canals Points : chapter maintenance of canals After the construction of irrigation system in an area is completed, it becomes essential to maintain it for its proper and efficient functioning. There are various reasons due k which a canal may cease to function difficulty. These are:
1. Silting of canal
2. Branching of canal due to weak banks.
3. Weed growth
4. Over flow of canal banks

Saturday, 8 April 2017

Canal Fall - Short Questions and Answers

Canal Fall - Short Questions and Answers Points : canal fall - short questions and answers Q:1 Write the basic requirement of canal fall. Ans: (1) suitable energy dissipation arrangement. (2) Fluming (3) crest level (4) low cost Q:2 Write down the classification of falls. Ans: Falls may be divided into four principal classes with reference to the approach conditions
(1) Falls designed to maintain the depth discharge relation
(2) Falls designed to maintain a fixed supply level in the cannaI above the work (3) Falls designed to admit the variations of the surface level above the work at the will of the operator
(4) Miscellaneous Types

Canal Fall

Canal Fall Points : Canal Fall Fall is an irrigation structure constructed across a canal to lower down its water level and destroy the surplus energy liberated from the falling water which may otherwise scour the bed and banks of the canal.

We have seen in chapter 14 that the canal requires a certain slope. Depending upon the discharge, to overcome the frictional losses. This slope may vary from 1 in 40000 for a discharge of about 1.5 cumecs to about 1 in 8000 for a discharge of 3000 cumecs. This slope is, therefore, quite flat in comparison to the available ground slope of in average value of 5 to 20 cm per kilometre length.

1. (in 200 to 1 in’50). Thus the ground slope in nature is always very much steeper than the design bed slope of irrigation canal, based on the silt theories. If an irrigation canal, taking off from its head, is in cutting, it will soon meet with condition when it will be entirely in embankment.

Saturday, 4 February 2017

Distribution Works

Distribution Works Points : distribution works, essential requirement of out let, types outlet, non-modular outlet, rigid module, non modular outlets pipe outlet, semi-module or flexible outlets, kennedy’s gauge outlet Outlets An outlet is a small structure which admits water from the distributing channel to a water course of field channel. Thus, an outlet 13 a sort of head regulator for the field channel delivering water to the irrigation fields. The responsibility of maintenance of the distributing channel and the whole canal network lies with Government, while that of the field channels lies with the farmer. The outlet is the connecting medium for the two. Essential requirement of out let Since the efficiency of a canal network mostly depends upon functioning of the out lets and other regulation works, a canal outlet should fulfill the following requirements.

1. The outlet should be strong, with no moving parts liable to be damaged or requiring periodic attention and maintenance.
2, It should be so designed that the farmer cannot temper with its functioning and any interference from him should be easily detectable.
3. Since a large number of out4ets are fixed. on a distributing channel, the moat essential requirement is that it should e cheap.
4. The design should be simple so that It can be constructed or fabricated by local masons or technicians,