Climatic controls on diffuse groundwater recharge across Australia

Abstract

Abstract. Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, the correlation between the modelled recharge and total annual rainfall is weaker than the correlation between recharge and the annual rainfall parameters reflecting rainfall intensity. Under similar soil and vegetation conditions for the same annual rainfall, annual recharge in regions with winter-dominated rainfall is greater than in regions with summer-dominated rainfall. The importance of climate parameters other than rainfall in recharge estimation is highest in the tropical climate type. Mean annual values of solar radiation and vapour pressure deficit show a greater importance in recharge estimation than mean annual values of the daily mean temperature. Climate parameters have the lowest relative importance in recharge estimation in the arid climate type (with cold winters) and the temperate climate type. For 75 % of all soil, vegetation and climate types investigated, recharge elasticity varies between 2 and 4 indicating a 20 % to 40 % change in recharge for a 10 % change in annual rainfall. Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.

Identifying flood recharge and inter-aquifer connectivity using multiple isotopes in subtropical Australia

“…1), located approximately 60 km east of the study site, is isotopically similar to rainfall collected from Toowoomba, which is located approximately 20 km to the southwest ( Fig. 8a; Crosbie et al, 2012). This suggests that there is limited spatial variation in the study region, and that data from Brisbane and Toowoomba are representative of the Cressbrook Creek catchment.…”

“…During the 12 months prior to the June 2011 sampling campaign, rainfall stable isotope signatures were depleted compared to previous rainfall events, particularly during, and immediately prior to, the flooding in January 2011. Rainfall from December 2010 and January 2011 (316 and 424 mm respectively; BOM, 2012) was particularly depleted in δ 2 H (−30.2 and −27.8, respectively) and δ 18 O (−5.34 and −5.13, respectively; Table 5) compared to the weighted average for rainfall, which was −3.4 and −12.7 for δ 2 H and δ 18 O respectively (Crosbie et al 2012). This confirms observations by Hughes and Crawford (2013), who also noted that high-precipitation rainfall events associated with east coast pressure systems in Australia can be significantly depleted.…”

“…Owing to this reliance on infrequent flooding and large rainfall events, alluvial aquifers are likely to be severely impacted by the predicted changes in climatic patterns, such as the projected increased frequency and severity of droughts and floods (Parry et al, 2007). This forecasted climate change will impact on river flows (Arnell and Gosling, 2013) and groundwater recharge processes (Green et al, 2011;Barron et al, 2012;. This is particularly relevant for alluvial systems which are connected to ephemeral or intermittent streams, as interactions between these streams and the alluvial aquifers are highly dependent on antecedent rainfalls (Hughes et al, 2011).…”

“…8) between May 2008 and May 2010 (Crosbie et al, 2012), and new data collected by ANSTO between June 2010 and June 2011 (Table 5). Rainfall collected from the Brisbane Airport (Fig.…”

Impact of climate indicators on continental‐scale potential groundwater recharge in Africa

“…Regional-scale studies in North America provide evidence of a decreasing trend in groundwater recharge under (historical or projected) global warming (Rosenberg et al, 1999;Ferguson and George, 2003). Other important climatic factors include solar radiation and vapor deficit, which significantly impact groundwater recharge rates in tropical zones (Vivoni et al, 2009;Barron et al, 2012).…”