Groundwater evaluation by using environmental isotopes in the northeast Missan governorate, South of Iraq

摘要

The present work studies the hydrochemical and the isotopic characteristics of the different parts of the main aquifer in the northeast Missan governorate, south of Iraq. Water samples for groundwater and surface water, were collected for two seasons, dry and wet, during 2011-2012. The study showed that the water, chemical types are Na-SO_4 and Na-Cl in the groundwater and Ca-Cl and Ca-SO_4 in the surface water. Isotopically, most of the groundwater in the aquifer falls above the global meteoric water line and slightly below the Mediterranean meteoric water line indicating that these samples are a mixture of two water types. The tritium~- content of these samples also supports this conclusion. The overall conclusion of this study indicates that there are three sources of groundwater recharge which are the ephemeral streams (Teeb and Dewerge) and rainfall water. According to the tritium levels at or below one tritium unit (TU) are obtained from water supply wells that are highly confined or "not vulnerable". Overall, tritium (~3H) values imply that recent recharge has taken place during the last three to four decades.