Channel-end discharge, rabi and kharif

Given: CCA = 400 ha; intensity rabi $= 65\%$, kharif $= 30\%$; outlet discharge factor (duty) rabi $= 1500$ ha/cumec, kharif $= 800$ ha/cumec; conveyance loss $= 6\%$ of the outlet discharge.

Areas: rabi $= 0.65\times400 = 260$ ha; kharif $= 0.30\times400 = 120$ ha.

Outlet discharge for each season

$$Q_{rabi} = \frac{260}{1500} = 0.1733\ \text{cumec},\qquad Q_{kharif} = \frac{120}{800} = 0.1500\ \text{cumec}$$

The design outlet discharge is the larger one: $Q_{outlet} = 0.1733$ cumec (rabi).

Conveyance loss

$$\text{Loss} = 0.06\times 0.1733 = 0.0104\ \text{cumec}$$ $$Q_{channel\ head} = 0.1733 + 0.0104 = 0.1837\ \text{cumec}$$

Answer: discharge required at the outlet (end of the channel) = 0.173 cumec; the channel must carry 0.184 cumec at its head to allow for the 6% loss.