Age and origin of groundwater resources in the Ararat Valley, Armenia: a baseline study applying hydrogeochemistry and environmental tracers

Abstract Within the Ararat Valley (Armenia), a continuously growing water demand (for irrigation and fish farming) simultaneous decline in groundwater recharge (due to climate change) result increasing stress on local resources. This detrimental development is reflected by groundwater-level drops an associated reduction of area with artesian conditions valley centre. situation calls for efforts aimed at more sustainable resources management. The aim this baseline study was collection data that allows origin age distribution based environmental tracers, namely stable (δ 2 H, δ 18 O) radioactive ( 35 S, 3 H) isotopes, as well physical-chemical indicators. results show receives modern recharge, despite its (semi-)arid climate. While subannual residence times could be disproved S), detected H pattern suggests ages several decades, oldest waters being recharged around 60 years ago. differing are varying scatter isotope hydrochemical signatures. presence young (i.e., younger 1970s), some containing nitrate, indicates vulnerability underscores importance increased achieve management natural resource. Since signatures indicate areas located mountains surrounding valley, these must not limited central part where most abstraction wells located.