TRITIUM CONTENT OF GROUNDWATER AQUIFER IN WESTERN NILE DELTA

Results of tritium content measurements of groundwater from western Ni le delta are presented and compared with the tritium content of the Ni le according to a given model. These results indicate the dependence o f the tritium concentration on the depth of well and geophysical struc ture of its location and also its proximity to irrigation channels. Th e mean residence time of the groundwater in the investigated wells ran ges from a few years to several hundreds of years. A contour map of tr itium concentration isolines illustrates the decrease of tritium conte nt values in the north direction towards the Mediterranean Sea due to sea-water intrusion. The clustered tritium isoline could be attributed to mixing with other water of older recharge. Also the salinity of gr oundwater increased in the direction of Mediterranean Sea which points out to sea-water intrusion in the groundwater.