Silt Excluder

Silt Excluder = In River Silt Ejector = In Feeder Channel Duty = ha / cumec Delta = Depth of water required for crop         

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Chemical quality of ground water (PH, Ec, carbonate, bicarbonate, chloride, Floride, hardness) Geology, topography and Soil Surveys Cropping pattern, command area and crop water requirements Irrigation Planning and water management Design of project features Economic analysis and justification Socio-economic aspects Environmental Aspects Catchment Area Treatment

Semi detailed soil survey by Soil profile (1mx1mx1.8 m) and auger holes (@ 500 m c/c both sides) Soil survey gives information on topographical features, present land use pattern, crops and cropping intensity, natural vegetation, settlement, location and extent of irrigation wells. Soil Fertility status by Organic Carbon (%), P2O2, K2O Land capability classification, land irrigability classification and soil fertility In soil available Nitrogen (N), Phosphorous (P 2O5), Potassium (K2O), organic matter. Net area = x ha, area sown more than once = y ha, Gross cropped area = x+y ha. Present cropping pattern & Proposed crop calendar commensurating field situation, soil climate. Cropping apttern for Kharif and Rabi crop. Net area = x ha, gross area = kharif + Ravi = y ha, cropping intensity = y/x = 100 to 200%. Culturable command area (CCA) = 6% of Gross Command Area (GCA), 40% deduction is due to topography, social, ecological reason, area occupied by houses, nallahs, canal network. Crop Evapo-transpiration. ET0 =Reference Evapo-transpiration = 10-18 cm tall cool season grass (uncut pasture) that is not water stressed. ET of Crop = ET0 x Crop Coefficient (Kc). ET0 determined by Penman Monteith method. Data required for working out ET0 by mean monthly temperature, relative humidity, sun shine hours and wind velocity.

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Determination of ET0 by computer program. ET0 = about 1000 mm by Penman method. Effective rainfall = total rainfall – surface runoff – deep percolation – evaporation. Effective rainfall = 75% - 80% of 75% dependable year. However, USBR method based on monthly rainfall values at 75% dependable year for command area is adopted. For crop water requirement, we need ET0, crop factor for crop at different stage of growth, effective rainfall contribution. In addition water for land preparation and puddling. Capacity of canal = maximum water requirement in a particular month x canal capacity factor. Field channel is for 5-8 ha. of land. Main canal along contour and distributaries along ridge to avoid cross drainage works. Rabi = Non Monsoon = Nov to April. Kharif = Monsoon = June to September. Seepage rate in lined canal = 1.16 cumec/ million km 2. No distributaries for area less than 5 ha. Area < 5 ha directly from main canal. Distributaries for minimum flow on 16 liter /sec (0.016 cumec) to keep minimum width of 0.3 m for maintenance purpose. Financial evaluation by NPV, BC Ratio and IRR.

01.05.2016 