Soil and Water Conservation Engineering Flashcards
Tambong - Part 2
Slope of the upstream face of the embankment.
Inside slope
Inside bottom or sill of the conduit.
Invert
Closed conduit designed to convey canal water in full and under pressure running condition, to convey canal water by gravity under roadways, railways, drainage channels and local depressions.
Inverted siphon
__________ water requirement is the amount of water required in lowland rice production which includes water losses through evaporation, seepage, percolation and land soaking.
Land preparation
_________ water requirement is the amount of water required in lowland rice production which is a function of the initial soil moisture and the physical properties of the soil.
Land soaking
Spacing between irrigation laterals.
Lateral spacing
Deep percolation of water beyond the root zone of plants, resulting in loss of salts or nutrients.
Leaching
Canal with impermeable material (usually concrete) for channel stabilization and/or reduced seepage.
Lined canal
Allowable pollutant-loading limit per unit of time, which the wastewater generator is permitted to discharge into any receiving body of water or land.
Loading limit
Portion of the pipe network between the mainline and the laterals.
Manifold
Spillway which is not excavated such as natural draw, saddle or drainage way.
Natural spillway
Constant flow depth along a longitudinal section of a channel under a uniform flow condition.
Normal depth
Maximum elevation of the water surface which can be attained by the spillway-type dam or reservoir without flow in the spillway.
Normal storage
Maximum elevation of the water surface which can be attained in an open channel without reaching the freeboard.
Design depth
In what condition is the open channel freeboard used for water conveyance?
Inundation
The primary purpose in limiting water flow not to go below minimum velocity.
Avoid sedimentation
Open channel flow is water flow that is conveyed in such a manner that top surface is exposed to the atmosphere such as flow in canals, ditches, drainage channels, culverts, and pipes under _____ flow conditions.
Partially full
Part of the system that impounds the runoff.
Reservoir
Slope at the downstream face of the embankment.
Outside slope
Ratio between reference evapotranspiration and water loss by evaporation from an open water surface of a pan.
Pan coefficient
Rate of water loss by evaporation from an open water surface of a pan.
Pan evaporation
Vertical flow of water below the root zone which is affected by soil structure, texture, bulk density, mineralogy, organic matter content, salt type and concentration.
Percolation
Vertical flow of water to carry salts contained in water.
Leaching
Method to determine the rate of flow under laminar flow conditions through a unit cross sectional area of soil under unit hydraulic gradient.
Permeability test
The process by which the soil is removed from its natural place.
Soil erosion
A kind of terrace which consists of a series of flattened areas.
Bench terrace
The practice where legumes are plowed or incorporated into the soil.
Green manuring
Farming practice where plowing and harrowing are done along the contour.
Contouring
The simplest method of determining soil erosion over a period of time.
Pin method
Advanced form of erosion.
Gully erosion
Dam which resists water flow of water by its weight.
Gravity dam
Dam consisting of stones enclosed in cyclone wires which allows water passage.
Gabion dam
Material used to cover the soil to minimize evapotranspiration.
Mulch
Geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rocks such as limestone or dolomite.
Karst topography
Scientific name of carabao grass commonly used in vegetated open channels.
Paspalum conjugatum
Philippine geographical constant for determining terrace vertical interval.
A. 0.5
Constant for soil erodibility and cover conditions for erodible soil and poor cover.
1
Estimate the peak runoff rate from a 20-hectare drainage basin if rainfall depth for 6 hours reached 60 mm. Use typical runoff coefficient of 0.35.
I = 60 mm/6 hrs = 10 mm/hr
q = 0.0028 CIA = 0.0028 (0.35)(10 mm/hr)(20 has) = 0.2 cms
Estimate the runoff volume from a 20-hectare drainage basin if rainfall depth for 6 hours reached 60 mm and duration of runoff is about 3 hours. Use typical runoff coefficient of 0.35.
I = 60 mm/6 hrs = 10 mm/hr q = 0.0028
CIA = 0.0028 (0.35)(10 mm/hr)(20 has) = 0.2 cms
Q = 0.5qT = 0.5 (0.2 cms) (3 hrs) (3600 s/hr) = 1,080 cms
