A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Land cover characteristics in NE Iceland with special reference to jokulhlaup geomorphology
Tekijät: Alho P
Kustantaja: WILEY-BLACKWELL
Julkaisuvuosi: 2003
Lehti:: Geografiska Annaler: Series A, Physical Geography
Tietokannassa oleva lehden nimi: GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY
Lehden akronyymi: GEOGR ANN A
Vuosikerta: 85A
Numero: 3-4
Aloitussivu: 213
Lopetussivu: 227
Sivujen määrä: 15
ISSN: 0435-3676
DOI: https://doi.org/10.1111/j.0435-3676.2003.00201.x
Tiivistelmä
Subglacial eruptions in Vatnajokull have accounted for several jokulhlaups (glacial outburst floods) in the Northern Volcanic Zone (NVZ). These events and aeolian processes have had a considerable impact on the landscape evolution of the area. Most of this area is occupied by barren land cover; the northern margin of the barren land cover is advancing northwards, burying vegetation under wind-blown sediment. This paper presents a land-cover classification based on a supervised Landsat TM image classification with pre-processing and extensive field observations. Four land cover categories were identified: (a) lava cover (34.8%); (b) barren sediment cover (39.0%); (c) vegetation (25.1%); and (d) water and snow (1.1%). The mapping of sand transport routes demonstrates that a major aeolian sand transportation pathway is situated in the western part of the study area. The sedimentary formation elongated towards the northeast is evidence of active and continuous aeolian sand transportation towards the north. Interpretation of the satellite image suggests that four main areas are affected by jokulhlaups along the Jokulsa a Fjollum: Asbyrgi, Grimsstaoir, Heroubreio-Moorudalur, and the Dyngjujokull sandur. In addition, jokulhlaup-related sediment cover (8%) in the study area, together with erosional features, are evidence of a severe and extensive jokulhlaup-induced process of land degradation.
Subglacial eruptions in Vatnajokull have accounted for several jokulhlaups (glacial outburst floods) in the Northern Volcanic Zone (NVZ). These events and aeolian processes have had a considerable impact on the landscape evolution of the area. Most of this area is occupied by barren land cover; the northern margin of the barren land cover is advancing northwards, burying vegetation under wind-blown sediment. This paper presents a land-cover classification based on a supervised Landsat TM image classification with pre-processing and extensive field observations. Four land cover categories were identified: (a) lava cover (34.8%); (b) barren sediment cover (39.0%); (c) vegetation (25.1%); and (d) water and snow (1.1%). The mapping of sand transport routes demonstrates that a major aeolian sand transportation pathway is situated in the western part of the study area. The sedimentary formation elongated towards the northeast is evidence of active and continuous aeolian sand transportation towards the north. Interpretation of the satellite image suggests that four main areas are affected by jokulhlaups along the Jokulsa a Fjollum: Asbyrgi, Grimsstaoir, Heroubreio-Moorudalur, and the Dyngjujokull sandur. In addition, jokulhlaup-related sediment cover (8%) in the study area, together with erosional features, are evidence of a severe and extensive jokulhlaup-induced process of land degradation.
Turun yliopiston Tutkimustietojärjestelmän portaali