Hydrology at its extreme: climate change, societal impacts and natural hazards in the land of fire and ice

There is a reason why Iceland is frequently called the land of fire and ice. Located on the mid-Atlantic ridge in the North Atlantic Ocean, Iceland is frequently exposed to explosive volcanic eruptions. Furthermore, due to its geographic location cold Arctic winds from the North and the warm humid winds coming from the Gulf of Mexico collide. The particular geographic location is the reason why over 10% of the Island area is covered by glaciers, precipitation can exceed 10´000 mm a-1, and glacial flood can reach several 100’000 m3 s-1. Regardless of the arctic winds, the extreme precipitation, and the frequent eruption, the original Icelandic vegetation has developed a resilience to with sand almost any natural hazard. However, with the arrival of the first settler over a millennium ago Iceland has been subject to dramatic deforestation due to intense sheep and horse farming. These anthropogenic impacts have severely mitigated the resilience of the Icelandic vegetation, altering the erosion patterns and finally also impacting the natural water flow. The Rangárvellir area in southern Iceland is an ideal location to study the interaction of human impacts, natural hazards, and consequences for the natural water cycle. Deforestation and intensive farming have decreased the resilience of the local ecosystems, leading to severe land degradation and extensive soil erosion. Since the beginning of the 20th century, diverse restoration measures have been implemented across Rangárvellir. Long-term monitoring programs demonstrate how restoration can help mitigate hydrometeorological and volcanic risks, providing a representative example of nature-based solutions. For this purpose, we present a metadatabase (http://rangarvellir.ru.is/) providing an overview of previous and ongoing research on land restoration, land management, reforestation, hydro-meteorological monitoring, and vegetation mapping. All relevant past and ongoing research and restoration projects are described in order to demonstrate the importance of an all-inclusive landscape restoration approach. The study concludes by outlining the importance of nature-based solutions and highlights the interaction between research projects in the frame of restoration and land reclamation efforts.