TY  - JOUR
A1  - Nussbaumer, S.
A1  - Schaub, Y.
A1  - Huggel, C.
A1  - Walz, Ariane
T1  - Risk estimation for future glacier lake outburst floods based on local land-use changes
JF  - Natural hazards and earth system sciences
N2  - Effects of climate change are particularly strong in high-mountain regions. Most visibly, glaciers are shrinking at a rapid pace, and as a consequence, glacier lakes are forming or growing. At the same time the stability of mountain slopes is reduced by glacier retreat, permafrost thaw and other factors, resulting in an increasing landslide hazard which can potentially impact lakes and therewith trigger far-reaching and devastating outburst floods. To manage risks from existing or future lakes, strategies need to be developed to plan in time for adequate risk reduction measures at a local level. However, methods to assess risks from future lake outbursts are not available and need to be developed to evaluate both future hazard and future damage potential.
 Here a method is presented to estimate future risks related to glacier lake outbursts for a local site in southern Switzerland (Naters, Valais). To generate two hazard scenarios, glacier shrinkage and lake formation modelling was applied, combined with simple flood modelling and field work. Furthermore, a land-use model was developed to quantify and allocate land-use changes based on local-to-regional storylines and three scenarios of land-use driving forces. Results are conceptualized in a matrix of three land-use and two hazard scenarios for the year 2045, and show the distribution of risk in the community of Naters, including high and very high risk areas. The study underlines the importance of combined risk management strategies focusing on land-use planning, on vulnerability reduction, as well as on structural measures (where necessary) to effectively reduce future risks related to lake outburst floods.
Y1  - 2014
U6  - https://doi.org/10.5194/nhess-14-1611-2014
SN  - 1561-8633
VL  - 14
IS  - 6
SP  - 1611
EP  - 1624
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Walz, Ariane
A1  - Braendle, J. M.
A1  - Lang, D. J.
A1  - Brand, Fridolin Simon
A1  - Briner, Simon
A1  - Elkin, C.
A1  - Hirschi, C.
A1  - Huber, R.
A1  - Lischke, H.
A1  - Schmatz, D. R.
T1  - Experience from downscaling IPCC-SRES scenarios to specific national-level focus scenarios for ecosystem service management
JF  - Technological forecasting & social change
N2  - Scenario analysis is a widely used approach to incorporate uncertainties in global change research. In the context of regional ecosystem service and landscape management where global IPCC climate simulations and their downscaled derivates are applied, it can be useful to work with regional sodo-economic scenarios that are coherent with the global IPCC scenarios. The consistency with the original source scenarios, transparency and reproducibility of the methods used as well as the internal consistency of the derived scenarios are important methodological prerequisites for coherently downscaling pre-existing source scenarios. In contrast to well-established systematic-qualitative scenario techniques, we employ here a formal technique of scenario construction which combines expert judgement with a quantitative, indicator-based selection algorithm in order to deduce a formally consistent set of focus scenario. In our case study, these focus scenarios reflect the potential development pathways of major national-level drivers for ecosystem service management in Swiss mountain regions. The integration of an extra impact factor ("Global Trends") directly referring to the four principle SRES scenario families, helped us to formally internalise base assumptions of IPCC SRES scenarios to regional scenarios that address a different thematic focus (ecosystem service management), spatial level (national) and time horizon (2050). Compared to the well-established systematic-qualitative approach, we find strong similarities between the two methods, including the susceptibility to personal judgement which is only partly reduced by the formal method. However, the formalised scenario approach conveys four clear advantages, (1) the better documentation of the process, (2) its reproducibility, (3) the openness in terms of the number and directions of the finally selected set of scenarios, and (4) its analytical power. (C) 2013 Elsevier Inc. All rights reserved.
KW  - Nested scenarios
KW  - Formalised scenario analysis
KW  - Regional ecosystem service management
KW  - Downscaling socio-economic scenarios
KW  - IPCC
Y1  - 2014
U6  - https://doi.org/10.1016/j.techfore.2013.08.014
SN  - 0040-1625
SN  - 1873-5509
VL  - 86
SP  - 21
EP  - 32
PB  - Elsevier
CY  - New York
ER  -