Research articleA methodological framework to assess the environmental and economic effects of injection barriers against seawater intrusion

•Injection barriers were used to control seawater intrusion.•A method to assess the impacts of injection barriers was developed.•The assessment was based on environmental and economic efficiency.•Spatio-temporal impacts of two artificial recharge schemes were evaluated.•Both recharge schemes provide an efficient solution for the study area.

Seawater intrusion is responsible for the progressive deterioration of groundwater quality in numerous coastal aquifers worldwide. As a consequence, seawater intrusion may constitute a serious threat to local groundwater resources, as well as to the regional economy of coastal areas. To alleviate these negative effects, a number of well-designed protective measures could be implemented. The implementation of these measures is usually associated with significant benefits for the environment and the local economy. In this perspective, the present study investigates the particular case of constructing injection barriers for controlling seawater intrusion by developing a methodological framework that combines numerical modeling with spatial and cost-benefit analyses. To this task, we introduce a novel approach, which considers the socio-economic aspects of seawater intrusion in the modeling procedure, and at the same time focuses on the spatial and temporal relationships between water salinity and farmers' income. To test the proposed methodology two alternative artificial recharge scenarios - with different volumes of water used for injection - are assessed. According to the results of this analysis, both scenarios are likely to have a positive impact on groundwater quality, as well as, a net economic benefit to local society.