16. Modeling of Seawater Intrusion in Coastal Area of River Andarax Delta (Almeria, Spain)

The problem of groundwater quality preservation in coastal regions faces almost all countries that have marine water areas, in particular, insular states. This problem is aggravated by the fact that coastal areas are commonly most habitable and industrially developed, and groundwater serves as a major source of drinking water supply to the population. Indeed, freshwater resources in the coastal aquifers are likely to experience disastrous and irreversible impacts due to overexploitation and ingress of seawater into freshwater aquifers. The latter process leads to a decrease in groundwater quality at water supply systems located within the coastal areas. Therefore, the management of groundwater resources in coastal aquifers requires special attention to minimize the extent of seawater intrusion into aquifers and upconing of seawater near pumping stations. Numerical modeling that treats density-dependent flow and miscible salt transport (Bear 1999; Zhang et al. 2004; Gingerich and Voss 2005; Giambastiani et al. 2007) can help in creating a basis for the relevant hydrogeological investigations and forecasting. This section is an example of model analysis of seawater intrusion into coastal aquifers, which naturally discharge into the Mediterranean Sea at a resort coastal zone in Almeria province (Spain).