Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

Abstract

Abstract. The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42 % to +5 % and from +8 % to +82 %, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72 % to an increase of 3 % for the four different analogue stations. The Gijon analogue station (Northern Spain), considered as the most representative for the near future climate state in the study area, shows an increase of 3 % of groundwater recharge for a 5 % increase of annual precipitation. Calculations for a colder (tundra) climate showed a change in groundwater recharge ranging from a decrease of 97 % to an increase of 32 % for four different analogue stations, with an annual precipitation change from −69 % to −14 % compared to the present-day climate.

Effect of temporal averaging of meteorological data on predictions of groundwater recharge

“…In this study we evaluated the different temporal scaling effects on groundwater recharge using the HYDRUS 1-D software package of Šimůnek et al (2013, 2016), which has been previously used in several other recharge studies (e.g., Assefa and Woodbury, 2013;Jiménez-Martinez et al, 2009;Leterme et al, 2012;Neto et al, 2016). Simulations were carried out for a 2-m deep unsaturated soil profile subject to transient meteorological conditions involving precipitation, evaporation and possible runoff.…”

“…While many methods exist for calculating recharge (e.g., Ngatcha et al, 2007;Scanlon et al, 2002), one common approach is to model variably saturated flow processes in the near-surface to partition precipitation into runoff, evaporation, root water uptake and deep drainage, and hence recharge (Assefa and Woodbury, 2013;Jiménez-Martinez et al, 2009;Leterme et al, 2012). Accurate modeling of vadose zone flow processes and recharge very much depends on having reliable weather data, including their temporal resolution such as daily versus monthly averaged data.…”

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

“…Hence, this method may not be applicable in many arid developing countries, as the monitoring system is often not sufficiently developed to properly characterize the system, e.g., the Middle East. Kløve et al (2014) stated that the quantification of climate change impact on GW reservoirs and recharge rates can be explored by GW models with future climate scenarios acquired from GCMs (e.g., Hanson and Dettinger, 2005;Dams et al, 2011;Leterme et al, 2012). Okkonen and Kløve (2011) carried out a sequential simulation of three models to estimate the temporal and spatial variation in surface-groundwater interaction.…”

Using Sap Flow Data to Parameterize the Feddes Water Stress Model for Norway Spruce

“…To account for the groundwater fluctuations in the riparian zone, the lower boundary condition for the wetter plot (Riparian) was set to deep drainage [51]. For the deep drainage option, the discharge rate at the bottom of the soil profile is defined as a function of the position of the groundwater table and the empirical parameters A qh and B qh [52]:…”