Alviela River Explained

Alviela
Length:51.16km (31.79miles)
Discharge1 Max:17m3/s[1]
Source1 Location:Olhos d’Água do Alviela, Alcanena
Source1 Elevation:135m (443feet)
Mouth:Tagus
Mouth Location:near Vale de Figueira
Mouth Elevation:23m (75feet)
Basin Size:180sqkm-331sqkm[2]
Custom Label:Tributaries
Custom Data:Ribeira dos Amiais, Ribeira de Carvalhos, Ribeira da Gouxaria

Alviela River (Portuguese: Rio Alviela, pronounced as /pt/) is a river in Portugal. It is 51.16km (31.79miles) long.[3] The Alviela spring is one of the deepest in the world and is locally connected to a cave complex that represents the most significant fluvio-karstic phenomena in Portugal, one which supports several bat colonies with more than 5,000 bats in total.[4] In 2007, a population of troglomorphic Procambarus clarkii, an invasive crayfish species, was recorded in the Alviela spring, raising concerns about their potential effect on native stygobitic fauna. These crayfish lack all body pigment, although pigmented specimens were recorded in nearby surface waters.[5]

The river has its origin in a karst spring. Ribeira dos Amiais, a losing stream, infiltrates through the Sumidouro da Ribeira dos Amiais, a ponor, only to return to the surface 250 m further on through a canyon.[6]

References

39.2944°N -8.6161°W

Notes and References

  1. Web site: Nascente dos Olhos de Água do Alviela, Alcanena . www.roteirodeminas.pt . 21 May 2021 . PT.
  2. Web site: Conhecer o Rio Alviela . 22 May 2021.
  3. Web site: Rio Alviela. 2012-09-22. snirh.inag.pt. Portuguese. http://arquivo.pt/wayback/20120126082442/http://snirh.inag.pt/junior/?menu%3D2.1%26item%3D17. 2012-01-26. dead.
  4. Web site: Mira Minde Polje and related Springs Ramsar Sites Information Service . rsis.ramsar.org . 21 May 2021.
  5. 2014 . Journal of Cave and Karst Studies . 86 . 1 . 62–65 . 10.4311/2013LSC0115 . free . A New Threat to Groundwater Ecosystems: First Occurrences of the Invasive Crayfish Procambarus clarkii (Girard, 1852) in European Caves . Mazza . Giuseppe . Sofia . Ana . Reboleira . P.S. . Goncalves . Fernando . Aquiloni . Laura . Inghilesi . Alberto . Spigoli . Daniele . Stoch . Fabio . Taiti . Stefano . Gherardi . Francesca . Tricarico . Elena .
  6. Web site: Ribeira dos Amiais, um trilho pela perda e ressurgência do PNSAC . Viajar entre Viagens . 22 May 2021 . pt-PT . 2020-04-15.