الفهرس 
Irrigation and agriculture crop water requirementsOnly 14 pages are availabe for public view
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Abstract
The study showed that the inflow of water into the canal was neither
continuous nor based on the conventional rotational system. Meanwhile,
it depends on both supply from the main canal and a connection with
made even more uncertain by the fact that around half with variation in
water levels from 0.6 m at the head to around 1.3 m at the tail/end of the
canal, which shows a major head-tail difference in water distribution and
no equity in water distribution.
Decreasing the pump discharge and shortage of water led to
increasing the number of pumping events. It was noted that the percentage
of events less than 30 minutes was about 37% of the total. This shows that
around one time out of three farmers are successful in pumping water
because of the too limited quantity of water available at the in front of the
pump intake.
Farmers prefer to start irrigation early in the morning for areas,
which suffer from a shortage of water. This is because of the decreasing
water pumping at night, which increases the water stored and level in the
canal and as well as at the end of the day.
Pump operations are not distributed well between different pump
units at the studied pumps due to the water shortage especially for the
pumps of the big area served led to operating two pump units with the total
discharge 83 l/s to cover the actual crop requirements of the big area
served in the pump station.
The value of water use index (WUI) was less than one, especially
during the high water demand period in summer. This means a difference
between the actual crop requirements and the actual applied water in the two pumps, which mean the canal is suffering from a shortage of water
and facing water problems leads to increasing un-official reuse of water.
The salinity of used water in the study area varied from around 500
µs cm
-1
at the head to 3000 µs cm-1 at the end of the canal and drains,
shows quite high values that mean that crops irrigated at those specific
times must have their yield affected by the high salt content.
Although pump station were supposed to replace individual pumps
(IP), but observed data analysis find an intensive use of individual pumps
was very common (more than 200 IP) were used overall the area served
on both canal and drains shows one major issue.
Increasing unofficial reuse of drainage water will be able to solve
the shortage of water and have a small negative impact on soil and/or
productivity. With the passage of time without good management to the
field, the soil classification will be changed to saline or alkaline soil. In
addition, the high reuse of drain water will have a negative impact on the
salt balance especially in the North Delta.
The management of the pump stations and the distribution pipe
systems were found to be quite an effective especially in the area of water
shortage and the benefits for marwa improvements were very high
comparing with masqa improvement.
Increasing the cultivated rice area from 46 - 60% provides
significant impacts on the field water conditions as well as yields of the
other crops and rice itself. Then, the rice production area is to be
controlled especially under water shortage conditions
The variation in productivity of rice and summer crop was not high
from different location in the canal. In the same time, it did not achieve the international productivity and this due to shortage of water, soil
properties and economic factors such as seeds variety, fertilizer and
harvest method.
Finally, the study suggests the following:
1. The improving irrigation in areas which having water deficit
problems and water scarcity areas will not achieve the goals and will
have a negative impact.
2. The Marwa improvement at on- farm level has a positive impact on
improving water applying efficiency and save water (such as social -
economic view).
3. Reusing water will solve problems of water deficit problems. But it is
necessary to put some policies to legalize the situation as official
reuse to decrease negative impact on salt balance.