Water — page 26 of 31

3,083 terms

Water terms

  1. Secchi depth A measure of water clarity.
  2. Second foot (sec-ft) Shortened term for cubic foot per second (cfs or ft3/s).
  3. Second-Day Feet The volume of water represented by a flow of one cubic foot per second for 24 hours; equal to 84,000 cubic feet.
  4. Secondary Embankment Embankment that blocks an area on a reservoiur rim that is lower than the top of the main dam. See also, "Levee".
  5. section An area equal to 640 acres or 1 square mile.
  6. Sediment Any finely divided organic and/or mineral matter deposited by air or water in nonturbulent areas.
  7. Sediment concentration The quantity of sediment relative to the quantity of transporting fluid, or fluid-sediment misture. The concentration may be by weight or by volume.
  8. Sediment discharge Rate at which sediment passes a stream cross-section in a given period of time, expressed in millions of tons per day (mtd).
  9. Sediment load Mass of sediment passing through a stream cross section in a specified period of time, expressed in millions of tons (mt).
  10. Sediment Storage Capacity The volume of a reservoir planned for the deposition of sediment.
  11. Sediment yield Amount of mineral or organic soil material that is in suspension, is being transported, or has been moved from its site of origin.
  12. Sediment yield rate The sediment yield per unit of drainage area.
  13. Sedimentary Rock resulting from the consolidation of loose eroded sediment, remains of organisms, or crystals forming directly from water.
  14. Sedimentation A process in which material carried in suspension by water flows into streams and rivers, increasing turbidity and eventually settling to the bottom.
  15. Seep A spot where ground water oozes slowly to the surface, usually forming a pool.
  16. Seepage The act or process involving the slow movement of water or other fluid through a porous material such as soil or rock.
  17. Seepage collar A projecting collar of concrete built around the outside of a tunnel or conduit, within an embankment dam, to reduce seepage along the outer surface of…
  18. Seepage force The force transmitted to the soil or rock grains by seepage.
  19. Seepage loss Water loss by capillary action and slow percolation.
  20. Seepage velocity The rate of discharge of seepage water through a porous medium per unit area of void space perpendicular to the direction of the flow.
  21. Seiche wave A wave generated by either a landslide into a reservoir or by a sudden displacement or deformation of a fault line in a reservoir floor during a major…
  22. Seismic Pertaining to any earth vibration, especially that of an earthquake.
  23. Seismic evaluation criteria A guideline for determining which faults or seismic sources need to be assigned MCE's.
  24. Seismic intensity Subjective measurement of the degree of shaking at a specified place by an experienced observer using a descriptive scale. See intensity scale.
  25. Seismic parameters Descriptors of earthquake loading or earthquake size, such as magnitude, peak acceleration, location (distance and focal depth), spectrum intensity, or…
  26. Seismo- Pertains to earthquakes.
  27. Seismotectonic Of, relating to, or designating structural features of the earth which are associated with or revealed by earthquakes.
  28. Seismotectonic Province A geographic area characterized by a combination of geology and seismic history.
  29. Seize To bind wire rope with soft wire, to prevent it from ravelling when cut.
  30. Select material Backfill materials specially selected and segregated from excavated materials.
  31. Semipervious zone. See transition zone.
  32. Sensitive species See Threatened, endangered, and sensitive species.
  33. Separation deposit Sand deposit located at the upstream end of a recirculation zone, where downstream flow becomes separated from the channel bank.
  34. Service Hydrologist The designated expert of the hydrology program at a WFO.
  35. Service spillway (primary spillway) A structure located on or adjacent to a storage or detention dam over or through which surplus or floodwaters which cannot be contained in the allotted…
  36. Settlement After negotiating, the amount you agree to accept from the insurance company as full payment for your loss.
  37. Setup This referes to various adjustments that are made to the race car's suspension for handling at a specific racetrack.
  38. Sewer tile Glazed waterproof clay pipe with bell joints.
  39. Shaft The vertical segment of a column or pilaster between the base and the capital.
  40. Shaft house House at top of the access shaft to gate chamber, which secures access to the gates.
  41. Shaft or Morning Glory Spillway A vertical or inclined shaft into which flood water spills and then is conducted through, under, or around a dam by means of a conduit or tunnel.
  42. Shaft spillway A vertical or inclined shaft into which water spills and then is conveyed through, under, or around a dam by means of a conduit or tunnel.
  43. Shale A rock formed of consolidated mud. Fine-grained sedimentary rock formed from hardened clay and silt that typically splits into thin layers.
  44. Shear Literally the sliding of one layer across another, with deformation and fracturing in the direction parallel to the movement.
  45. Shear strength Internal resistance to stress (or movement) that comes from friction and cohesion of the sediment.
  46. Shear wall A vertical lateral-force-resisting element in a structure assigned to resist wind or earthquake generated lateral forces.
  47. Shear zone An area where the rock mass has moved along the plane of contact which often becomes a channel for ground water.
  48. Sheepsfoot roller A tamping roller having lugs with feet extending at their outer tips.
  49. Sheet Flow Flow that occurs overland in places where there are no defined channels, the flood water spreads out over a large area at a uniform depth.
  50. Sheet piling Steel strips shaped to interlock with each other when driven into the ground.
  51. Sheet wash A flow of rainwater that covers the entire ground surface with a thin film and is not concentrated into streams.
  52. SHEFPARS A software decoder for SHEF Data.
  53. shell See shoulder.
  54. Shelterbelt A natural or planned barrier of trees or shrubs to reduce erosion and provide shelter from winds or storms.
  55. Sheltering (in-place) A protective action that involves taking cover in upper levels of a building that is able to withstand high flood levels.
  56. Shore ice An ice sheet in the form of a long border attached to the bank or shore; border ice.
  57. Shoring Temporary bracing to hold the sides of an excavation from caving.
  58. Short-throated flumes Short-throated flumes are considered short because they control flow in a region that produces curvilinear flow.
  59. Shoulder (shell) The upstream and downstream parts of the cross section of an embankment dam on each side of the core or core wall.
  60. Shrinkage Loss of bulk of soil when compacted in a fill.
  61. Shrinkage index (SI) The numerical difference between the plastic and shrinkage limits.
  62. Shrinkage limit (SL) The maximum water content at which a reduction in water content will not cause a decrease in volume of the soil mass.
  63. Shrinkage ratio (R) The ratio of a given volume change, expressed as a percentage of the dry volume, to the corresponding change in moisture content above the shrinkage…
  64. Side Channel Spillway A spillway whose crest is roughly parallel to the channel immediately downstream of the spillway.
  65. Significant hazard A downstream hazard classification for dams in which 1-6 lives are in jeopardy and appreciable economic loss (rural area with notable agriculture…
  66. Significant Wave Height The average height of the one-third highest waves of a given wave group.
  67. Sill 1.The lower horizontal part of a window frame or window opening; also the accessory member which extends as a weather barrier from frame to outside face…
  68. Silt (rock flour) The fine-grained portion of soil that is nonplastic or very slightly plastic and that exhibits little or no strength when air dry.
  69. Silting Filling with soil or mud deposited by water.
  70. Siltstone A sedimentary rock made mostly of silt-sized grains.
  71. Simulid Group of two-winged flying insects who live their larval stage underwater and emerge to fly about as adults.
  72. Single-stage pump A pump that has only one impeller.
  73. Sink Any process, activity, or mechanism which removes a greenhouse gas, an aerosol, or a precursor of a greenhouse gas or aerosol from the atmosphere.
  74. Sinkhole A steep-sided depression formed when removal of subsurface embankment or foundation material causes overlying material to collapse into the resulting void.
  75. Sinuosity The ratio of the length of a river's thalweg to the length of the valley proper. A measure of a river's meandering. Rivers with a sinuosity less than 1.
  76. Siphon A pipe connecting two canals. A tube or pipe through which water flows over a high point by gravity.
  77. Siphon Spillway A spillway with one or more siphons built at crest level. This type of spillway is sometimes used for providing automatic surface-level regulation within…
  78. Siphon tube Relatively short, light-weight, curved tube used to convey water over ditch banks to irrigate furrows or borders.
  79. Siphonage A partial vacuum created by the flow of liquids in pipes.
  80. Site In archeology, any location of past human activity.
  81. Site Specific Hydrologic Prediction System (SSHP) (SSHP) The WFO hydrologic forecast model for small rivers and streams that uses RFC soil moisture state variables, stage and precipitation data.
  82. Site-Specific A term used to describe any process or enzyme which acts at a defined sequence within a DNA or RNA molecule.
  83. Skewed Tilted images. See De-skewing.
  84. Skimmer gate A gate at the spillway crest whose prime purpose is to control the release of debris and logs with a limited amount of water.
  85. SKIP A non-digging bucket or tray that hoists material
  86. Skiving To dig in thin layers.
  87. Slab A concrete pad that sits on gravel or crushed rock, well-compacted soil either level with the ground or above the ground.
  88. Slaking The process of breaking up or sloughing when an indurated soil is immersed in water.
  89. Slate Fine-grained metamorphic rock formed by "baking" and recrystallizing shale or mudstone and which splits easily along flat, parallel planes.
  90. Sleet Precipitation that consists of clear pellets of ice; sleet is formed when raindrops fall through a layer of cold air and freeze.
  91. Slide A small landslide.
  92. Slide gate A steel gate that upon opening or closing slides on its bearings in edge guide slots. A gate that can be opened or closed by sliding in supporting guides.
  93. Slide Gate (Sluice Gate) A gate that can be opened or closed by sliding it in supporting guides.
  94. slope An inclined surface usually defined by the ratio of the horizontal distance to the vertical distance, i.e. 2:1 (2 horizontal units to 1 vertical unit).
  95. Slope Protection The protection of an embankment slope against wave action or erosion.
  96. Slough A long, narrow stretch of water such as a small stream or feeder tributary off a lake or river.
  97. Slug Large initial amount. A unit of mass which will undergo an acceleration of 1 foot per second squared when a force of 1 pound is applied to it.
  98. Sluice An opening for releasing water from below the static head elevation.
  99. Sluice gate A gate that can be opened or closed by sliding in supporting guides.
  100. Sluiceway An opening in a diversion dam used to discharge heavy floating debris safely past the dam.

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