Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia | Evolution du niveau piézométrique et des relations nappe-rivière en réponse à la variabilité climatique : bassin de Clarence-Moreton (Australie) Respuesta del nivel del agua subterránea y de la interacción agua superficial/agua subterránea a la variabilidad climática: Cuenca Clarence-Moreton, Australia 气候变化对地下水以及地表水-地下水交互的影响:澳大利亚Clarence-Moreton盆地 Resposta do nível das águas subterrâneas e interação águas superficiais/águas subterrâneas à variabilidade climática: Bacia Clarence-Moreton, Austrália

2018

Cui, Tao | Raiber, Matthias | Pagendam, Dan | Gilfedder, Mat | Rassam, David

Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (−0.7 m/year) and ascending (2.1 m/year) Sen’s slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

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