Page 56 - Water and DSİ

Basic HTML Version

55
CHAPTER IV - IRRIGATION
Because it is not possible to reduce water amount in crop water requirements, water economy
could only be applied in water conveyance, distribution, system operation and application within
the area. Theoretically, there are operational (conveyance) losses 5% in main canals and 5% in the
schemes, adding up to 10%. These losses reach to great amounts in practice. In large irrigation
schemes, decreasing of these losses have greater importance. Pressurized pipe systems in newly
developed irrigation projects increase water economy therefore modern irrigation systems are to be
encouraged. The ratio of the system using pressurized pipe is 14%, however, with future projects
and rehabilitation of old schemes this ratio would become 71%. On the other hand, when
irrigation water are reached to the farm, on-farm water loses constitute the major proportion of the
total water losses in irrigation. Therefore the most important factor is the increase of farm
efficiency. Instead of traditional methods, if sprinkler and drip irrigation methods are utilized,
efficiency will increase from 60% to 80% and 90% respectively. It means 20% and 30% water
economy.
In order to achieve maximum benefit from water sources, DSI has shifted its policy from classical
open channel distribution network to more water saving systems. Pipeline distribution network has
been utilized extensively. Especially in inland areas where the water sources are scarcer this
becomes a major issue. The proportion of pipeline distribution has soared to 71% in projects
under the construction while it is 14% in the projects in operation.
As of
2011, 42% of existing
canals is classic canal, the %44 is canalettes (raised concrete parabolic flume).
Irrigation Canal Types and Lengths (km) as of 2011
SU İLETİM VE DAĞITIM KANALLARI
3 703
32 373
27 847
7 723
71 647
0
10000
20000
30000
40000
50000
60000
70000
80000
( km )
Unlined Lined Canalette
Pipe
Total
HISTORICAL DEVELOPMENT PROCESS OF IRRIGATION IN TURKEY