Simulated response of groundwater to predicted recharge in a semi-arid region using a scenario of modelled climate change

Abstract

Groundwater systems in arid regions will be particularly sensitive to climate change owing to the strong dependence of rates of evapotranspiration on temperature, and shifts in the precipitation regimes. In agricultural areas, such changes in climate may require increased irrigation, putting stress on existing water supplies. In this study, a regional-scale numerical groundwater model was developed for the Oliver region of the south Okanagan, British Columbia, Canada, to simulate the impacts of future predicted climate change on groundwater. In future time periods (the 2050s and 2080s), the most noticeable change in the water budget is the increased contribution of recharge to the annual water budget, estimated at 1.2% (2050s) and 1.4% (2080s) of the total annual budget relative to the current conditions. This increase is related primarily to increases to irrigation return flow resulting from higher irrigation needs under warmer temperatures and a longer growing season. Increases in recharge and irrigation return flow will result in higher water tables with future climate conditions, particularly in the irrigation districts. Median value increases in groundwater level of up to 0.7 m by the 2080s are estimated.

Climate change impact on groundwater levels: ensemble modelling of extreme values

“…Only a few of these simulate groundwater conditions with a physically based groundwater flow model (e.g. Yosoff et al, 2002;Scibek and Allen, 2006;van Roosmalen et al, 2007;Candela et al, 2009;Toews and Allen, 2009). The general interest of these studies is water resources, where quantifications of groundwater recharge and responding groundwater levels at seasonal timescales are adequate.…”

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

“…Moreover, most studies on the impacts of climate change on recharge have focused on changes in total annual or monthly precipitation (Appaih-Adjei, 2006;Scibek and Allen, 2006;Toews and Allen, 2009;Jyrkama and Sykes, 2007); few have considered how shifts in the frequency and magnitude of events could influence groundwater aquifers (Taylor et al, 2013b;Owor et al, 2009;Mileham et al, 2009). …”

Coupled modeling approach to assess climate change impacts on groundwater recharge and adaptation in arid areas

“…While there is uncertainty in climate change projections regarding whether there will be an increase or decrease in temperature and precipitation in most parts of the world (e.g., McMichael et al, 2004;Bell et al, 2004;Zhang et al, 2006;Priyantha Ranjan et al, 2006;Jyrkama and Sykes, 2007;Beniston et al, 2007;Giorgi and Lionello, 2008;Toews and Allen, 2009;Barthel et al, 2012), the majority of climate models predict a noticeable decrease in precipitation and an increase in temperature in the arid Middle East (e.g., Bou-Zeid and El-Fadel, 2002;Felis et al, 2004;Abbaspour et al, 2009;Evans, 2009Evans, , 2010.…”

“…The main aim of studying climate change impacts on GW systems is to predict the (1) changes in GW recharge rate in different recharge periods (e.g., Eckhardt and Ulbrich, 2003;Scibek and Allen, 2006;Jyrkama and Sykes, 2007;Toews and Allen, 2009;Meddi and Boucefiane, 2013) and to predict the (2) change in GW levels (e.g., Surinaidu et al, 2013;Goderniaux et al, 2009). These objectives are commonly achieved through numerical modeling approaches.…”

“…It is assumed that the direct areal recharge to the aquifer occurs from a combination of weather data, stream, soil characteristics, vegetation, and land cover data. Some widespread models using this method are HELP and SWAT (e.g., Eckhardt and Ulbrich, 2003;Jyrkama and Sykes, 2007;Toews and Allen, 2009;Abbaspour et al, 2009). The linear storage models, also known as bucket models, define the role of soil moisture for ETP by distinguishing radiation-limited regimes and soil moisture-limited regimes (Seneviratne et al, 2010); i.e., in which a near-surface layer of soil is modeled as a storage that can be filled by infiltrating precipitation and exposed to evaporation and runoff if filled up (Henderson-Sellers et al, 1993).…”