Different hydrological response of mountain snowpacks to climate warming
Abstract
Climate warming will reduce the duration of mountain snowpacks and spring runoff, impacting the timing, volume, reliability and source of water supplies to the mountain headwaters of rivers that support a large proportion of humanity. It is often assumed that snow hydrology will change proportionately to climate warming, however, this assumption oversimplifies the complex physical processes that drive precipitation phase and snowmelt. Here, snow hydrology predictions from a physically based virtual basin hydrology model driven by current and future temperature conditions in mountains around the world have confirmed a generalized decoupling of mountain river hydrology from headwater snow regimes, thus most river regimes shifted from relying on snowmelt timing to synchronizing with seasonal precipitation. But also we found high variability in the hydrological response to warming. In particular, the decline in snow accumulation and duration to climate warming is both substantial and highly variable, yet highly predictable from air temperature and humidity data. Hydrological regimes showed higher resilience and less variability to warming than snowpacks. However,predictions of hydrological sensitivity based on the sensitivity of snowpack to warming are highly reliable butlargest decoupling of river regimes from snow regimes will occur in those areas where precipitation mostly occurs during the cold season. There was no link between the magnitude of changes in the snowpack and changes in annual runoff.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H13H..07L
- Keywords:
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- 0740 Snowmelt;
- CRYOSPHERE;
- 1621 Cryospheric change;
- GLOBAL CHANGE;
- 1813 Eco-hydrology;
- HYDROLOGY;
- 1817 Extreme events;
- HYDROLOGY