Quantifying Alpine water demands: setup for a micro- observatory of irrigation and drinking water supply in the Crans-Montana-Sierre region (Valais, Switzerland)

CALIANNO, MARTIN; REYNARD, EMMANUEL

Fribourg

Conferencia; 12th Swiss Geoscience Meeting; 2014

Several integrated studies on water management have recently been conducted in the Alps. They main aim is to confront water resources to water use in order to identify water scarcity issues that could possibly occur in mountainous regions (Bonriposi, 2013). Regarding the quantification of water resources availability, these works often rely on well-known hydro-climatic science and exhaustive datasets. However, regarding water use, direct measurements are rare and researchers either depend on rough estimations given by water managers or create indirect datasets using proxies. Therefore, there is a strong need to correctly quantify water uses and to define a monitoring methodology in Alpine regions (Reynard, 2000).This poster puts forward the setup of a field campaign in Central Valais. It aims at quantifying water supplies for the two main water uses of the area: irrigation and drinking water. This campaign is divided into three steps:1°) A clarification and definition of concepts related to water use. This preliminary step is essential to understand the meaning of the measurements that will be undertaken.2°) A study on the spatial and temporal extent of water uses. This second part gives insights on the spatial and temporal patterns of Alpine water uses, thus allowing comparisons and production of consistent water balances.3°) A case study, where the results of the two previous steps are applied. A micro-observatory of water supplies is currently being set up in the investigated area, with direct and continuous measurements.This micro-observatory is located in the Crans-Montana-Sierre hillside and focuses on two water uses.The first one is drinking water related to the Crans-Montana mountain resort. Based on currently existing equipment and new established monitors (installed on water meters), starting October 2014, water supplies will be continuously measured for three years at different time steps. Currently, water meters of the Montana municipality are already set up with radio transmitters, enabling monthly to daily measurements. In addition, smart metering will be set on a sample of users (2 hotels, 1 apartments block and 2 chalets), thus allowing hourly measurements. Additional radio transmitters will also be installed on a sample of existing water meters (for 2 hotels, 2 villas and 2 apartments blocks) in the municipality of Sierre, located in the Rhone River valley. This fully equipped setting will thus provide continuous monitoring of drinking water supply from high altitudes down to the Rhone River Valley.Water supplies for irrigation will be also quantified. A water meter will be set up on an irrigated grasslands parcel and another one upstream of the vineyards irrigation network. These meters will be read manually during the irrigation season.Finally, qualitative interviews will be undertaken among actors of these water uses in order to define users’ characteristics, to better understand habits and practices and, subsequently, to explain the figures collected by the micro- observatory. This will then allow us to draw some indicators forecasting water uses in similar contexts.