SHOTS - HYDROLOGY & IRRIGATION
🔥 Border flooding is used on rolling land.
🔥 Delta=(8.64B/D).
🔥 The duty is largest on the field.
🔥 The ‘outlet discharge factor’ is the duty at the head of water course.
🔥 Water application efficiency is the ratio of water stored in the reservoir to the water delivered in the field.
🔥 Useful water for plant growth is capillary water.
🔥 consumptive irrigation requirement The amount of irrigation water required to meet the evapotranspiration needs of the crop during its full growth
🔥 Hydrograph is the graphical representation of runoff and time.
🔥 Soil moisture deficiency-the depth of the water required to bring the soil moisture content to the field capacity.
🔥 Cyclonic precipitation is caused due to the lifting of an air mass due to the pressure difference.
🔥 Convective precipitation is caused due to the temperature difference.
🔥 Simons rain gauge is the non recording rain gauge.
🔥 Tipping bucket type of rain gauge is used in inaccessible areas.
🔥 Convex water surface will give highest rate of evaporation.
🔥 A current meter is used for measuring the velocity of flow of water.
🔥 An artesian aquifer is the one where water is under pressure between two impervious strata.
🔥 A deep well has more discharge than shallow well.
🔥 The useful storage is the volume of water stored between minimum pool level and normal pool level.
🔥 Trap efficiency of a reservoir is a function of capacity/inflow ratio.
🔥 The major resisting force in a gravity dam is self weight of the dam.
🔥 When the reservoir is full the maximum compressive force in a gravity dam is produced with in the middle third of base.
🔥 The elementary profile of a gravity dam is a right angled triangle.
🔥 The maximum permissible eccentricity for no tension at the base of gravity dam is B/6.
🔥 For wave action in gravity dams the maximum height of freeboard is generally taken 1.25hw.
🔥 Seepage through embankment in earthen dam is controlled by drain trenches.
🔥 Ogee spillway is least suitable for earthen dam.
🔥 In chute spillway the flow is usually super critical.
🔥 A divide wall is provided at right angle to the axis of weir.
🔥 Silt excluder is constructed on river bed upstream of head regulator.
🔥 Contour canal-canals run parallel to the contours of the country.
🔥 Side slope canal-canals run perpendicular to the contour of the country.
🔥 Garrets diagram is used in Kennedys theory.
🔥 According to lacey’s theory the eddies are generated from bottom as well as sides.
🔥 Canal escape is used to remove surplus water.
🔥 Kennedy’s gauge outlet is flexible outlet.
🔥 Montague type fall is parabolic glacis.
🔥 Meter fall is a vertical drop fall.
🔥 Rigid module is constant discharge.
🔥 Flexibility-the ratio of rate of discharge of an outlet to the rate of change of discharge of distributing channel.
🔥 An aggrading river is a silting river.
🔥 Scouring river is degrading river.
🔥 River training is achieved by groynes and bandalling.
🔥 A repelling groyne is pointing upstream.
🔥 A river training work is generally required when the river is meandering.
🔥 Cetyl alcohol is used in water surface to reduce the evaporation.
🔥 In linear reservoir storage varies linearly with outflow rate.
🔥 1 gauge for 520km^2 in plain areas,
🔥 1 gauge for 260km^2 in 1000m elevation about mean sea level
🔥 1 gauge for 130km^2 in hilly areas.
🔥 The double mass analysis is adopted to check the consistency of data.
🔥 In upstream slope of an earthen dam the most critical condition is sudden draw down condition.
🔥 Permanent wilting point is a soil characteristic.
🔥 Mean precipitation over an area is best obtained by orographical isohyetal method.