Landscape scale measurements of wind erosion of volcanic materials in the Hekla area

• Main Author: Elín Fjóla Þórarinsdóttir 1967-
• Other Authors: Landbúnaðarháskóli Íslands
• Format: Master Thesis
• Language: English
• Published: 2010
• Subjects: Heklugos; Vindrof; Vatnsrof; Umhverfisþærttir; Uppgræðsla; Hekla; Iceland; Þjórsá
• Online Access: http://hdl.handle.net/1946/7340

Wind erosion is one of the principal factors responsible for desertification. Due to volcanic activity, harsh climate and unsustainable land use, Iceland has extensive desert areas where wind erosion in common. The objectives of the present study were to i) measure aeolian sand transport on a landscape scale, ii) to estimate the effect of environmental factors on sand transport and iii) estimate the effect of reclamation efforts on wind erosion. The research area, north of Hekla in South Iceland, extends approximately 110 km2 of barren or sparsely vegetated land, with sandy lava fields and sand and pumice fields dominating the surface. Wind erosion was studied for two summers, 2008-2009, on a landscape scale, by measuring the actual aeolian sand transport during erosion events with dust traps at 32 locations. Electronic sensors, meteorological data, field mapping, remote sensing and GIS analysis were also used to measure sand transport and estimate the effect of reclamation efforts and environmental factors on wind erosion. The aeolian sand transport ranged from negligible to approximately 150 kg m-1 hr-1 at locations with the most intensive erosion. At some of the most active aeolian transport sites the mass sand transport was >1 t m-1 per summer and at one location it was almost 3 t m-1 during the summer of 2008. There are interactions between aeolian and fluvial processes within the research area. The most active erosion areas are in the northeast, fed by aeolian sediment sources, but an active pathway for aeolian sand movement runs through the research area from the north-eastern part, along the hillsides of Valafell and then into the Þjórsá river, mostly along a major seasonally active waterway. Therefore, both aeolian and fluvial sediment sources affect the erosion intensity. Environmental factors considerably affect the wind erosion and my conclusion is that field mapping of surface characteristic can be used to estimate erosion susceptibility. Image classification and spatial analysis based on field ...