干旱区生态环境知识资源中心

Water in the coastal areas are limited. This problem is intensified due to sea water intrusion which results from the reduction in ground water (GW) level as water demand exceeds annual GW recharge. The capability to predict the dynamics of salt water is essential in managing water resources in coastal areas. This study analyzes the process of sea water (SW) intrusion which is a major cause for salination of GW in coastal areas in general and in coastal semi-arid regions in particular. The analysis is based on numerical simulation of the two dimensional process transport of water and salts.

The simulation of 100 years of interactive water demands (pumping) at several levels, rain and salts intrusion suggests that continuous pumping beyond the annual recharge may be associated with sea water intrusion to a distance of several hundreds and thousands of meters from the sea water line. Our project indicated also that over pumping often occurs in coastal and and semi and regions (ASAR).

Four representative cases were simulated here.

1. Turkey: The delta of the Tahtah river near Izmir on the Aegean sea, an important Satsuma growing region.

2. Spain: The delta of the Almogoro river (Near Malaga) flowing toward the western end of the Mediterranean.

3. Gaza strip: A sand dune area representing a case of un-isotropic and heterogeneous aquifer in the Eastern end of the Mediterranean.

4. Portugal: The strip of flat coast is very narrow and the source of the GW is rain (800-1000 mm/year) on steep neighboring mountains. The aquifer is heterogeneous and water head is high.

All four cases indicated a certain distance of saline water intrusion and are discussed in details in the paper.