COMPARISON OF WATER SUPPLY AND DEMAND FOR THE RABI SEASON AT TERTIARY LEVEL IN THE COMMAND OF THE JUI SHEIKH CANAL IRRIGATION SYSTEM

摘要

The research study was conducted on a selected site in the command area of the Jui Sheikh Canal near Peshawar. Crop water requirements of the area were determined and then compared with the water supply during the Rabi season (November 1991-May 1992).Crops for the season at the site were wheat and alfalfa, sown on areas of 9.8 ha and 1.9 ha respectively. The seasonal reference evapo-transpiration (ETo) was 459 mm. The seasonal crop evapo-transpiration of wheat and alfalfa was 424 mm and 393 mm respectively. The seasonal volume of water required by wheat and alfalfa was 4184 m~3/ha and 3928 m~3/ha respectively and the total volume required was 3229.2 m~3/ha. Flow of water in the watercourse was observed in the months of November. December. March, April and May. There was no canal water available in January and February due to annual canal closure for maintenance. Volume of water received by the area from the canal was 16658 m~3/ha. The contribution from effective rainfall was 648 m~3/ha. The totalseasonal water supply to the area was 17306 m~3/ha. A comparison between the water supply and the water requirements was made, showing that the water supply was in excess of the requirements by about 80%.