Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland

Reconstruction of the past is mainly based on work with 14 palaeochannels, 22 stratigraphical sections, 15 pollen diagrams, 43 radiocarbon dates and geomorphological mapping. Of the results revealed the most important are: low water balance of (1) the Boreal and (2) the Early Subboreal (around 480...

Full description

Bibliographic Details
Main Author: Leo Koutaniemi
Format: Article
Language:English
Published: Geographical Society of Finland 1987-01-01
Series:Fennia: International Journal of Geography
Online Access:https://fennia.journal.fi/article/view/9045
_version_ 1828849605366775808
author Leo Koutaniemi
author_facet Leo Koutaniemi
author_sort Leo Koutaniemi
collection DOAJ
description Reconstruction of the past is mainly based on work with 14 palaeochannels, 22 stratigraphical sections, 15 pollen diagrams, 43 radiocarbon dates and geomorphological mapping. Of the results revealed the most important are: low water balance of (1) the Boreal and (2) the Early Subboreal (around 4800 B.P.), (3) step‑wise in­crease in water balance approx. 2000 B.P. connected with intense activation in meander shifting. (4) continuing of this situation in the present form 1500–1600 B.P., and (5) the highest level of all in fluvial activity during the Little Ice Age. None of these features were affected by Man. Changes in post‑glacial fluvial activity are reflected, first of all, in the reverse trends of lateral and vertical channel movements. the last‑mentioned being strongly regulated by the isostatic land uplift. The dominance of the climatic factors over those of the glacio‑isostatic origin in controlling Ho­locene fluvial work appears to increase the more the closer to the present day we come. These effects are to be seen in the activation of lateral shifting. The concentration of coarse lag deposits at the valley bottoms may have contributed in intensifying lateral movements in the near past. The research made calls for great methodological caution in palaeo­hydrological interpretation of fluvial environments.
first_indexed 2024-12-12T22:55:22Z
format Article
id doaj.art-1cd88da846ad48a883df00e10e683130
institution Directory Open Access Journal
issn 1798-5617
language English
last_indexed 2024-12-12T22:55:22Z
publishDate 1987-01-01
publisher Geographical Society of Finland
record_format Article
series Fennia: International Journal of Geography
spelling doaj.art-1cd88da846ad48a883df00e10e6831302022-12-22T00:08:58ZengGeographical Society of FinlandFennia: International Journal of Geography1798-56171987-01-011651Palaeohydrology of the rivers Ivalojoki and Oulankajoki, FinlandLeo Koutaniemi0Department of Geography, University of OuluReconstruction of the past is mainly based on work with 14 palaeochannels, 22 stratigraphical sections, 15 pollen diagrams, 43 radiocarbon dates and geomorphological mapping. Of the results revealed the most important are: low water balance of (1) the Boreal and (2) the Early Subboreal (around 4800 B.P.), (3) step‑wise in­crease in water balance approx. 2000 B.P. connected with intense activation in meander shifting. (4) continuing of this situation in the present form 1500–1600 B.P., and (5) the highest level of all in fluvial activity during the Little Ice Age. None of these features were affected by Man. Changes in post‑glacial fluvial activity are reflected, first of all, in the reverse trends of lateral and vertical channel movements. the last‑mentioned being strongly regulated by the isostatic land uplift. The dominance of the climatic factors over those of the glacio‑isostatic origin in controlling Ho­locene fluvial work appears to increase the more the closer to the present day we come. These effects are to be seen in the activation of lateral shifting. The concentration of coarse lag deposits at the valley bottoms may have contributed in intensifying lateral movements in the near past. The research made calls for great methodological caution in palaeo­hydrological interpretation of fluvial environments.https://fennia.journal.fi/article/view/9045
spellingShingle Leo Koutaniemi
Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland
Fennia: International Journal of Geography
title Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland
title_full Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland
title_fullStr Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland
title_full_unstemmed Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland
title_short Palaeohydrology of the rivers Ivalojoki and Oulankajoki, Finland
title_sort palaeohydrology of the rivers ivalojoki and oulankajoki finland
url https://fennia.journal.fi/article/view/9045
work_keys_str_mv AT leokoutaniemi palaeohydrologyoftheriversivalojokiandoulankajokifinland