Explain in brief "silt controlling" in irrigation weir?

Thanks for the invitation

I am so sorry as i can,t answer that question

In fact it,s not my specialization field & i am going to follow up the answers

 but  i do agree with the answers given by Mr.:Gapher zien

Silting can be controlled by constructing "a diversion head work"- weir or barrage a cross a perennial river to rise water level and to divert the water to a canal,and the flow of water is controlled by "canal head regulater".

Diversion head work controls the entry of silt into canals and the "under sluices" known as scouring sluices are the openings provided at the base of the weir or barrage with adjustable gates normally goes on depositing in front of the canal head regulator. When the silt deposition becomes appreciable the gates are opened and the deposited silt is loosened with an agitator mounting on a boat and the muddy water flows towards the downstream through the scouring sluices.

السلام عليكم والرحمة استاذي الفاضل شكرا على الدعوة لكن ليس لدي خبرة بموضوع اعلاه كوني تخصص ( انشاءات ) وليس الري ، لكني اتمنى لو تتفضل عليّ وتزيدني من خبرتك في هذا الموضوع وانا والحمدلله خبرتي لاتتجاوز خبرتك الكبيرة واني سوف انتظر اجابتك بفارغ الصبر .. وشكرا

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Silt Regulation works 

  The entry of silt into a canal, which takes off from a head works, can be reduced by constructed certain 

special works, called silt control works.  

These works may be classified into the following two types: 

(a)  Silt Excluders 

(b)  Silt Ejectors 

(a) Silt Excluders 

  Silt excluders are those works which are constructed on the bed of the river, upstream of the head 

regulator. The clearer water enters the head regulator and silted water enters the silt excluder. In this type 

of works, the silt is, therefore,, removed from the water before in enters the canal. 

 (b) Silt Ejectors 

  Silt ejectors, also called silt extractors, are those devices which extract the silt from the canal water after 

the silted water has traveled a certain distance in the off-take canal. These works are, therefore, constructed 

on the bed of the canal, and little distance downstream from the head regulator.