Ecosystem approach for natural hazard mitigation of volcanic tephra in Iceland: building resilience and sustainability

Abstract

Living in Iceland, a highly volcanically active island with a historical eruption frequency of 20–25 events per 100 years, involves risks from lava, pyroclastic flows, tephra-fall, and floods from glacier/snow-covered volcanoes. Volcanic eruptions can have detrimental effects on human health, societies, and ecosystems. Eruptions in 2010–2011 proved the value of pre-event planning for some natural hazards. An additional focus is needed on pre-disaster mitigation responses for the effects of tephra-fall on vegetation: As outlined under the UNISDR Hyogo/Sendai Framework for Action, healthy ecosystems and environmental management are key actions in disaster risk reduction (DRR). Iceland’s most serious environmental problem is the degraded state of common rangeland in the highlands, where tephra-fall has been catastrophic. Tephra (airborne volcanic material) affects hydrology, air quality, and ecosystems by direct burial or post-eruptive transport, extending its influence far beyond the initial eruption area. Resilience to tephra-related disturbances depends on an ecosystem’s overall health. Tall, vigorous vegetation has greater endurance; its initial survival is more likely, while sheltering minimizes secondary transport and hastens recovery. Areas that are sparsely vegetated and already stressed are more vulnerable; there, tephra remains unstable and can cause further damage. Reclaiming vulnerable land and building healthy ecosystems, as represented by the Hekluskógar project, improve the ability of these areas to endure tephra-fall, increasing their resilience and reducing the associated costs to society. Successful DRR for tephra-fall, through the revegetation of degraded land, will require effective governance, multi-sector coordination, and the alignment of policies on land use, agriculture, natural resource management, and climate change mitigation.