General Irrigation Terminologies 2 PDF

2.76 open channel flow 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 partially full flow conditions 2.77 optimal emitter spacing drip emitter spacing which is 80% of the wetted...

2.76 open channel flow 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 partially full flow conditions 2.77 optimal emitter spacing drip emitter spacing which is 80% of the wetted diameter estimated from field tests 2.78 outside slope slope at the downstream face of the embankment 2.79 pan coefficient ratio between reference evapotranspiration and water loss by evaporation from an open water surface of a pan 2.80 pan evaporation rate of water loss by evaporation from an open water surface of a pan 2.81 percolation vertical flow of water to below the root zone which is affected by soil structure, texture, bulk density, mineralogy, organic matter content, salt type and concentration 2.82 permeability test method to determine the rate of flow under laminar flow conditions through a unit cross sectional are of soil under unit hydraulic gradient 2.83 pollutant any substance, whether solid, liquid, gaseous or radioactive, which directly or indirectly alters the quality of any segment of the receiving water body or land resource so as to affect or tend to affect adversely any beneficial use thereof, or is hazardous or potentially hazardous to health, or imparts objectionable odor, temperature change or physical, chemical or biological change to any segment of the water body or land, or is in excess of the allowable limits or concentrations or quality standards specified in contravention of the condition, limitation or restriction prescribed in these guidelines 9 2.84 pond sealed section formed between earth embankments where combined seepage and percolation will be measured 2.85 potential irrigable area area capable of being irrigated, principally as regards to availability of water, suitable soils, and topography of land 2.86 reference crop evapotranspiration rate of evapotranspiration from a reference surface which is a hypothetical reference crop with an assumed crop height of 0.2 m, a fixed surface resistance of 70 s/m and an albedo of 0.23 2.87 reservoir part of the system that impounds the runoff 2.88 residual moisture content moisture left in the soil before the initial irrigation water delivery which describes the extent of water depletion from the soil when the water supply has been cut-off restricted areas areas with limited entry such as freeway landscape, highway medians and other similar areas 2.89 re-use taking wastewater from one industry or process, treating it and then using it in another process or industry such as for irrigation, as liquid fertilizer and for aquaculture 2.90 road crossing conveys canal water under roads or railroads 2.91 shallow tubewell tube or shaft vertically set into the ground at a depth that is usually less than 15 m for the purpose of bringing groundwater into the soil surface whose pumps are set above the water level 2.92 seismicity occurrence or frequency of earthquakes in a region 10 2.93 seepage water escaping below or out from water conveyance facilities such as open ditches, canals, natural channels, and waterway 2.94 seepage line phreatic line line with no filter arrangements where seepage occurs 2.95 setback distance distance from the perimeter of the irrigation area to the community or area of concern that is sensitive to contamination 2.96 side slope ratio of the horizontal to vertical dimension of the channel wall 2.97 slope of the energy grade line slope of the water surface profile plus the velocity head in open channels 2.98 slope of the hydraulic grade line slope of the free water surface 2.99 spillway channel which releases surplus or flood water which cannot be contained in the active storage space of the reservoir 2.100 sprinkler irrigation method of applying irrigation water similar to natural rainfall where water is distributed through a system of pipes by pumping and then sprayed into the air through sprinklers so that it breaks up into small water drops which fall to the ground 2.101 sprinkler spacing distance between two sprinkler heads along the lateral 2.102 storage capacity total capacity at normal water surface elevation 11 2.103 storage ratio ratio of the storage capacity to the total earth volume required for embankment construction which indicates the relative cost of the different types of reservoir 2.104 structural height vertical distance measured from the top of the dam down to the bedrock 2.105 surface irrigation system application of water by gravity flow to the surface of the field. Either the entire field is flooded (basin irrigation) or the water is fed into small channels (furrows) or strips of land (borders) 2.106 top width width of the channel cross-section at the free surface 2.107 unconfined aquifer aquifer which has water table serving as upper surface of the zone of saturation 2.108 uniformity coefficient ratio of the particle size at 60% pasing to that at 10% passing 2.109 uniform flow occurs when flow has a constant water area, depth, discharge, and average velocity through a reach of channel 2.110 unimodal rainfall pattern rainfall pattern with five wet months of more than 200 mm/month, five dry months of less than 100 mm/month, two transition months of 100mm- 200mm/month and total annual rainfall above 1500 mm. 2.111 unlined channels unlined canal canals that are cut through the soil, in which the soil excavated from the bed are used to form the embankment 2.112 upstream face side of the embankment wetted by the impounded water 12 2.113 waste any material either solid, liquid, semi-solid, contained gas or other forms resulting from industrial, commercial, mining, or agricultural operations, or from community and household activities that is devoid of usage and discarded 2.114 wastewater waste in liquid state containing pollutants 2.115 water balance accounting of water inflows, such as irrigation and rainfall, and outflows, such as evaporation, seepage and percolation 2.116 watershed area which contributes runoff or drains water into the reservoir 2.117 water right privilege granted by the government to use and appropriate water 2.118 well log record of formation stratification of an aquifer showing the depth, thickness, degree of consolidation and other aquifer physical characteristics 2.119 well-protected reservoir reservoir where the upper reaches of the basin is shielded by high mountain barriers 2.120 wetted diameter diameter of the circular area wetted by the sprinkler when operating at a given pressure and no wind 2.121 wetted perimeter portion of the perimeter of the canal that is in contact with the flowing water 2.122 wetted widths width of the strip that would be wetted by a row of emitters spaced at their optimal spacing along a single lateral line 13 2.123 zoned embankment dam consisting a central impervious core flanked between zones of more pervious materials 3 Bibliography Allen, R.G., Pereira, L.S., Raes D. and M. Smith. 1998. FAO Irrigation and Drainage Paper No. 56 Crop Evapotranspiration (Guidelines For Computing Crop Water Requirements) American Society of Agricultural and Biological Engineers (ASABE). 2007. ASAE S526.3 SEP2007 Soil and Water Terminology American Society of Agricultural and Biological Engineers (ASABE). 2008. ASAE EP419.1 FEB1993(R2008) Evaluation of Irrigation Furrows Booher, L.J. 1974. FAO Agricultural Development Paper 95: Surface Irrigation Brouwer, C. np. Irrigation Water Management Training Manual No. 5: Irrigation Methods Chow, V.T. 1959. Open Channel Hydraulics. McGraw Hill Book Company, Inc. New York. David, W.P., Firmalino R.B. and L.C. Tecson. Proposed Methodologies/Strategies for the Development of Location-Specific Irrigation Design Criteria David, W.P, M.G. Villano, C.U. Collado, Jr., E.B. Razote and A.L. Ecito. 1997. Technical Bulletin No. 1 Gintong Ani Shallow Tubewell Irrigation Project: Design, Installation and Development of Shallow Tubewell. DA-UPLBFI STWIP David, W.P. and M.A. Dorado. n.d. Gintong Ani STWIP: Aquifer Characterization David, W.P. n.d. Chapter IV: Shallow Tubewell Construction and Development Department of Agriculture Administrative Order No. 26 Series of 2007: Guidelines on the Procedures and Technical Requirements for the Issuance of a Certification Allowing the Safe Re-Use of Wastewater for Purposes of Irrigation and Other Agricultural Uses Department of Agriculture – Bureau of Soils and Water Management. 1997. Manual for Agrohydrology and Engineering Design for Small Water Impounding Project (SWIP) Department of Agriculture – Bureau of Soils and Water Management. 2013. Training Presentations. 14