Geography of the European Netherlands European part of the country can be split into two areas: the low and flat lands in the west and north, and the higher lands with minor hills in the east and south. The former, including the reclaimed polders and river deltas, make up about half of its surface area and are less than above sea level, much of it actually below sea level. An extensive range of seawalls and coastal dunes protect the Netherlands from the sea, and levees and dikes along the rivers protect against river flooding. The rest of the country is mostly flat; only in the
Water resources management in modern Egypt Nile sediments. Furthermore, agricultural land losses will occur as a result of soil salinization. The extent of vulnerability of the Nile delta to increases in sea level varies. One study estimates that 30% of the Delta and Alexandria coast is vulnerable, 55% is "invulnerable" and 15% was artificially protected in 2003. High-risk areas in and near the Delta include parts of Alexandria, Behaira, Damietta and Port Said governorates. According to Omran Frihy, a retired coastal researcher, authorities are spending US$300 million to build concrete sea walls to protect the beaches of Alexandria. Sand is being dumped in some areas to