Vulnerability of water resource management to climate change: Application to a Pyrenean valley

Study region: The Aure Valley in the French Pyrenees. Study focus: This study applies a bottom-up framework for assessing water management vulnerability in terms of hydropower production, environmental regulations, and reservoir storage management by integrating the sensitivity, the management metrics with the participation of stakeholders, and the exposure of the water system. The hydrological model GR6J-CEMANEIGE is implemented to simulate the management metrics in the study region. The sensitivity of management metrics to climate change is investigated by comparing simulation results under current climate conditions and under perturbed climate series. Results are demonstrated with response surfaces, which are overlaid with the predefined thresholds of management metrics. The thresholds help identifying climate conditions that are critical for water management. Plausible climate change pathways are displayed on the response surfaces to assess the probability of critical conditions. New hydrological insights for the region: Results show that annual hydropower production is mostly vulnerable to future drier conditions. Environmental metrics are sensitive to both precipitation and temperature changes while the current policy render the low-flow management less susceptible to risks. Reservoir storage management is found to be extremely sensitive to temperature increase that induces an earlier snowmelt. Although downstream water use is less vulnerable to climate change even under a high greenhouse gases emissions scenario, more intense water competition among stakeholders could be foreseen. Corresponding adaptation actions are proposed to reduce the vulnerability.

Automated summary

This study assesses the vulnerability of water management in the Aure Valley in the French Pyrenees by integrating sensitivity, management metrics, stakeholder participation, and water system exposure. Results show that hydropower production is vulnerable to drier conditions, while environmental metrics are sensitive to both precipitation and temperature changes. Reservoir storage management is extremely sensitive to temperature increase, and more intense water competition among stakeholders is foreseen. Adaptation actions are proposed to reduce the vulnerability.