Peter Essick – National Geographic

Global climate is changing due to fossil fuel use and other human activities.  Analysis of global trends show an observed increase of 1°C in globally-averaged surface temperature and a predicted additional 2-4°C over the next 100 years.  Change in temperature and other climate variables such as humidity and precipitation, however, show substantial spatial variation. Some locations in northern Canada for example show temperature increases of more than XC since the 1950s. Climate change impacts will also be region-specific.  Our lab uses models to understand and predict what these impacts are likely to be.

Water supply may be particularly vulnerable to changes in climate since warming can significantly impact many components of the water cycle, including precipitation, snow accumulation and melt, evapotranspiration, soil moisture, and runoff.   Changes in water availability can also significantly alter ecosystems by changing productivity, sensitivity to disturbances such as fire and disease and over longer time frames ecosystem composition and biodiversity. These changes in ecosystems can in turn influence surface and groundwater resources!

Analyses of observed streamflow and other hydrologic data show a wide range of water system responses to climate change, from streamflow increases in certain regions to more frequent and severe droughts in others.  Explaining these differences requires understanding not only the local climate, landscape, and ecosystem controls on water, but also how these controls shift and interact under warmer conditions.  Eco-hydrologic modeling can bridge this gap between historical observations and future projections, and therefore assist in local assessment of climate change impacts on water resources and potential adaptation strategies. At the bottom of this page you will find a few papers where we have used models to better understand climate change impacts on water resources.

Oroville Dam- Getty Images

Oroville Dam- Getty Images

Research Questions:

  • What determines surface and groundwater patterns in a particular place?
  • Are the variables that influence surface and groundwater likely to change under climate warming and if so, how and how quickly?
  • How do temperature, water availability and other climate related variables influence ecosystems and their vulnerability to disturbances?
  • How do climate driven changes in ecosystems influence water resources?
  • How might land management (thinning, logging, development) interact with climate change to influence water supplies and other ecosystem services?
  • How can we adapt to a changing climate though land and water resource management?



Relevant Publications: 

  • Godsey, S.E., Kirchner, J.W., Tague, C.L. (2014) Effects of changes in winter snowpacks on summer low flows: case studies in the Sierra Nevada, California, USA, Hydrological Processes 28(19): 5048-5064. doi: 10.1002/hyp.9943. 


  • López-Morenoa, J.I., Zabalzaa, J., Vicente-Serranoa, S.M., Revueltoa, J., Gilabertea M., Azorin-Molinaa, C., Morán-Tejedab, E., García-Ruiza, J.M., Tague, C. (2014) Impact of climate and land use change on water availability and reservoir management: Scenarios in the Upper Aragón River, Spanish Pyrenees, Science of the Total Environment 493(15): 1222-1231. doi: 10.1016/j.scitotenv.2013.09.031.


  • Tague, C., Peng, H. (2013) The sensitivity of forest water use to the timing of precipitation and snowmelt recharge in the California Sierra: Implications for a warming climate, Journal of Geophysical Research: Biogeosciences 118(2): 875-887. doi: 10.1002/jgrg.20073.


  • Tague, C., and Grant, G. (2009) Groundwater dynamics mediate low flow response to global warming in snow-dominated alpine regions, Water Resources Research 45: W07421: doi:10.1029/2008WR007179.


  • Hwang, T.; Band, L.E.; Vose, J.M.; Tague, C. (2012) Ecosystem processes at the watershed scale: Hydrologic vegetation gradient as an indicator for lateral hydrologic connectivity of headwater catchments, Water Resources Research 44(6): W06514.