Portugal - Atlas do Ambiente I.17 - Carta da Hidrografia Continental

Summary

The Chart «Hydrography and Main Catchment Areas of Portugal» was based on data from the «Hidrographic Index and Decimal Classification of the Portu- guese Watercourses», published by «Direcção-Geral dos Recursos e Aproveita- mentos Hidráulicos» now renamed «Direcção-Geral dos Recursos Naturais» (DGRN). The main rivers flowing from Spain to the Atlantic Ocean, sometimes as part of the border between Portugal and Spain, share their catchment areas. This is true as to the Minho, Lima, Douro, Tejo and Guadiana rivers, as well as to a number of their tributaries. The catchment area of these rivers covers in Spain about 2.3 times the total area of the Portuguese mainland. These natural conditions should be taken into consideration when planning and managing the Portuguese hydrologic resources. Several Conventions between Portugal and Spain have been approved, being in force the ones signed in 1964 and 1968. The 1964 Convention regulates the hydroelectric development of international stretches of the Douro river and its tributaries. The 1968 Convention regulates the hydraulic use and development of the rivers Minho, Lima, Tejo, Guadiana, Chança and their tributaries. 6