Natural and anthropogenic factors for activation of marine intrusion on the Bulgarian Black Sea coast

Coping  with water deficit in coastal areas is a challenge when groundwater extraction must be relied upon. The problem is exacerbated when favourable conditions appear for activation of marine intrusion. Such could be significant pressure on groundwater bodies from water abstraction, which causes a change in the water level and, accordingly, a change in the direction of the groundwater flow. The present paper presents hydrological and water resource management analysis  of factors for activation of marine intrusion on the Bulgarian Black Sea coast using data from  monitoring observations of water quantity and quality  and hydrological model simulations. Anthropogenic impacts are analyzed using information about the actual structure and dynamics of the water supply.

The results of the research show that in the Bulgarian Black Sea coastal zone the rainfalls in the past decade are below the country average. Hence marine intrusion processes are observed in the central and northern part of the region due to excess water intake from groundwater for domestic water supply. This imposes the necessity of searching alternative water sources from other territories and specific methods for water treatment.

Key words: water deficit, groundwater water abstraction, marine intrusion, Bulgarian Black Sea coast