the Ebro river makes up the second largest delta in the Western Mediterranean in terms of area, with an emerged surface of some 320 km2 and levels that are very close to sea level (60%, has an elevation less than 1 meter). It is the second most important wetland in the Western Mediterranean region and the most significant natural environment on the Catalan coast.
The Delta has three main areas that are distinguished: the delta land environment, the costal and transition environments, and the marine environment. The front coastline is 51 km long.
The Ebro Delta is made up of a geological system that is constantly evolving, as a result of erosion and the shifting and depositing of materials and sediment throughout the water basin; of costal and sea deterioration; of changes in sea level, and of the dynamics of the planet Earth.
The variation in average annual flow and the amount of water contributed at Tortosa show a significant decline over the last 100 years, with a reduction of more than 30%. This decrease is due to both human impact as well as reasons that are directly associated with climate change.
The Ebro drainage basin is regulated by 190 different dams and reservoirs, the most important being those at Flix, Riba-Roja, and Mequinensa, which cause retention of the majority (almost 99%) of sediment.
The deficit in sediment accentuates the natural phenomenon of subsidence that occurs in the whole Delta region with patterns of subsidence in the Delta at an average rate of 3 mm/year,
As a consequence of the rising sea level, by the year 2100, between 45% and 60% of the surface of the Ebro Delta could be flooded.
The erosion is set at, on average, between 0.60 and 0.90 m/year. The Cap de Tortosa, the beaches Riumar, la Marquesa and Trabucador, and the salt ponds at Trinitat are areas where sediment is lost and the coastline recedes; and the beaches of Fangar and l’Eucaliptus, and Punta de la Banya, are on the receiving end.
The Ebro Delta is notably agricultural. The land is mainly used for harvesting rice crops, which takes up more than 65% of the surface. Riparian forests are the only type of forested area in the delta.
Fishing activity is centered around five fishing ports (Sant Carles de la Ràpita, L’Ametlla de Mar, L’Ampolla, Deltebre and les Cases d’Alcanar) and six fishing associations, which make up 25% of all the fishing boats in Catalonia.
Aquaculture activity is an important source of income for the area’s economy. More than 75% of Catalan businesses in that sector are located in the delta area
However, in the past decade, production has suffered an important loss in terms of quantity and quality, due to the lack of freshwater entering the bays and rising sea temperatures.
Natural habitats make up 20% of the area and include marine and land systems, continental waters and limnetic zones, many of which are protected by national and international figures.
The waterfowl population makes up approximately 90% of the total in Catalonia; and the populations of ducks and shorebirds, more than 60%.