Bruno Schädler

Assessing the sustainability of water governance systems: the sustainability wheel

We present and test a conceptual and methodological approach for interdisciplinary sustainability assessments of water governance systems based on what we call the sustainability wheel. The approach combines transparent identification of sustainability principles, their regional contextualization through sub-principles (indicators), and the scoring of these indicators through deliberative dialogue within an interdisciplinary team of researchers, taking into account their various qualitative and quantitative research results. The approach was applied to a sustainability assessment of a complex water governance system in the Swiss Alps. We conclude that the applied approach is advantageous for structuring complex and heterogeneous knowledge, gaining a holistic and comprehensive perspective on water sustainability, and communicating this perspective to stakeholders.

General Characteristics of Alpine Waters

The elements of the water balance, namely precipitation, runoff, evapo- transpiration, and storage change, their interaction and special attributes in the mountains are presented using the example of the European Alps, with particular reference to Switzerland. Strong differentiation in the alpine climate over time and space exerts a significant influence on the water cycle. This chapter therefore discusses each of the elements of the water balance with particular reference to the influence of mountains and their measurement, as well as the spatial differenti- ation characteristics. The analysis of the water balance is accompanied by a discussion on the attributes and differences at different altitudes and in different climatic regions. Finally, the importance of alpine water resources for water supplies in the adjacent lowlands is examined.

Robust estimates of climate-induced hydrological change in a temperate mountainous region

A sustainable water resources management depends on sound information about the impacts of climate change. This information is, however, not easily derived because natural runoff variability interferes with the climate change signal. This study presents a procedure that leads to robust estimates of magnitude and Time Of Emergence (TOE) of climate-induced hydrological change that also account for the natural variability contained in the time series. Firstly, natural variability of 189 mesoscale catchments in Switzerland is sampled for 10 ENSEMBLES scenarios for the control (1984–2005) and two scenario periods (near future: 2025–2046, far future: 2074–2095) applying a bootstrap procedure. Then, the sampling distributions of mean monthly runoff are tested for significant differences with the Wilcoxon-Mann–Whitney test and for effect size with Cliff’s delta d. Finally, the TOE of a climate change induced hydrological change is determined when at least eight out of the ten hydrological projections significantly differ from natural variability. The results show that the TOE occurs in the near future period except for high-elevated catchments in late summer. The significant hydrological projections in the near future correspond, however, to only minor runoff changes. In the far future, hydrological change is statistically significant and runoff changes are substantial. Temperature change is the most important factor determining hydrological change in this mountainous region. Therefore, hydrological change depends strongly on a catchment’s mean elevation. Considering that the hydrological changes are predicted to be robust in the near future highlights the importance of accounting for these changes in water resources planning.

Impact of Climate Change on Water Resources in the Alpine Regions of Switzerland

Alpine regions have been and will be responding sensitively to global climate change compared to other European regions. This chapter analyses past and future changes in the climate of the Alps and its consequences on the elements of the water cycle. One obvious consequence is the melting of European glaciers by more than 65% since the end of the Little Ice Age in 1850. As a result of temperature increase hydrological regimes are changing. How will climate and water balance change in the future? Scenario results for the European Alps and in more detail for the Swiss Alps are discussed. Consequences in inner Alpine valleys are less precipitation in summer and hence more droughts.

Montanaqua: tackling water stress in the alps: water management options in the crans-montana-sierre region (valais)

MontanAqua: Tackling Water Stress in the Alps. Water Management Options in the Crans-Montana-Sierre Region (Valais) GAIA 25/3(2016): 191–193 |

Water Management Options Under Climate Change in the Swiss Alps

The touristic region of Sierre–Crans-Montana–Plaine Morte is located in one of the driest valleys of Switzerland. In the MontanAqua project, researchers analysed how climate change and socio-economic changes are likely to affect water availability and water use in the region by 2050, based on four development scenarios. The analyses generated five key governance messages for sustainable water management. Water Management Options Under Climate Change in the Swiss Alps

Water Towers in a Changing World

Global assessments of mountain water resources are challenging owing to the limited data available. An initial comprehensive global overview was recently created based on a set of global maps at a resolution of 50 × 50 km2 (Figure 2.1; Viviroli et al 2007). Analysis of this overview shows that even in temperate climates, which are relatively water-abundant, mountains deliver about twice as much runoff per unit area as lowlands. In arid zones, mountains provide as much as 7 times more runoff than lowlands; in these dry water-scarce zones, mountains frequently contribute as much as 90% or more to the total runoff of a river basin (Figure 2.2, Viviroli et al 2003). The importance of mountains is particularly pronounced in subtropical regions with a high variability of precipitation, especially if they depend on a single rainy season. Cases in point are the countries of monsoon Asia, such as India and Pakistan, as well as Southeast Asia and southern China, where about 1.3 billion people or close to 20% of the global population depend on mountain waters from the Himalaya, Karakoram, and Tien Shan massifs and from Tibet. Other large mountain systems critically important for water supply are the Rocky Mountains, the Andes, the mountains of the Middle East, the Atlas Mountains, and the mountains of South Africa. In addition, a number of regional ‘water towers’ found on each continent play a key role. In East Africa, for example, Mount Kenya is the only source of freshwater for over 7 million people.