Agricultural drainage water management in arid and semi ... - FAO.org

xivAcronym/ Description DimensionsymbolS e water extraction sink (m 3 m -3 d -1 ) T -1Se hp maximum selenium concentration in harvested product (mg kg -1 ) -Se I selenium concentration in irrigation water (µg litre -1 ) M L -3S end salts in the rootzone at the end of the period (ECmm) T 3 I 2 M -1 L -2S p lateral seepage (mm) LSe ss selenium concentration in soil solution (µg litre -1 ) M L -3Se ssm maximum selenium concentration in soil solution (µg litre -1 ) M L -3S i seepage inflow (mm) LS IW salts in infiltrated water (ECmm) T 3 I 2 M -1 L -2S R salts in percolation water from the rootzone (ECmm) T 3 I 2 M -1 L -2S start salts in the rootzone at the start of the period (ECmm) T 3 I 2 M -1 L -2S v vertical seepage (mm) Lt time (d) TTDS total dissolved solids (mg litre -1 , g litre -1 ) M L -3TSS total suspended solids (mg litre -1 , g litre -1 ) M L -3V dw volume of drainage water (m 3 ) L 3V gw volume of groundwater (m 3 ) L 3V i volume of irrigation water (m 3 ) L 3Y empirical correction factor -Y r relative yield -W fc moisture content at field capacity (mm) LWT water table depth (m) Lz vertical coordinate (m) L