Irrigation Questions

• Lacey’s regime condition: According to Lacey, regime flow is obtained under which foundational circumstance for an alluvial channel?
• Available soil-water storage in the root zone: A soil has field capacity = 25% and permanent wilting point = 15%. The specific dry unit weight is 1.5 (relative to water = 1.0). For a crop with an 80 cm root zone, what is the storage capacity (available water) expressed as an equivalent depth of water?
• In irrigation engineering, the consumptive use of water (also called crop water use) for a standing crop is equal to which depth of water? Select the most complete description of the water components involved.
• In soil–water–plant relations, “useful moisture” of soil is defined as which of the following within the effective root zone of plants?
• Kor watering and outlet factor: If the optimum depth of kor watering for a crop is 15.12 cm, determine the outlet factor (hectares per cumec) for a four-week (28-day) kor period.
• Falls in canals: A fall (drop) in the canal bed is generally provided under which ground and design slope condition?
• Guide bank design practice: The downstream expansion head (curved end) of a guide bank is commonly extended to subtend which angle at the centre?
• Exit gradient at downstream of a weir or barrage floor as per Khosla’s theory: On which non-dimensional parameter does the exit gradient primarily depend?
• Depth at canal outlet considering efficiencies: Irrigation efficiency is 80%, conveyance losses are 20%, and the actual depth needed on the field is 16 cm. What depth of water must be supplied at the canal outlet?
• Montague type fall in canals: What is the characteristic form of the glacis provided in a Montague fall?
• Hydraulic structure safety: A hydraulic structure (e.g., a barrage or weir with floor and cutoffs) must be designed to withstand which of the following actions?
• In irrigation agronomy, which form of soil water is actually available for plant uptake during the crop growth period? Choose the most useful moisture form for plant growth.
• Laplace equation solution technique: For three-dimensional potential-flow problems of water (e.g., in a siphon or seepage domain), which method is commonly used to obtain a numerical solution of the Laplacian field?
• Open-channel measurement with a venturi flume: If D is the upstream depth above the throat sill and B is the throat width, what is the theoretical maximum discharge Q for critical flow in the throat?
• In a gravity canal, the Full Supply Level (F.S.L.) relative to the natural ground is generally kept at what elevation to ensure economy and safety in earthwork?
• Bligh’s creep theory for seepage under hydraulic structures: Along which path is the percolating water assumed to travel under a weir or barrage floor when computing creep length?
• Selecting a site for canal headworks: Among the listed river stages, which location is generally most suitable for constructing canal headworks to ensure stability and a dependable intake?
• Drainage canals: What name is given to canals that are specifically constructed to relieve and convey excess water from water-logged or poorly drained areas?
• Siphon-aqueduct design practice: What is the usual limiting velocity range (in m/s) adopted for drainage water flowing through the barrels of a siphon-aqueduct to avoid excessive head loss, vibration, and abrasion?
• Soil-plant-water relation: The condition at which plants can no longer extract sufficient moisture from the soil for their needs is called the ________.