Evolution of the groundwater system under the impacts of human activities in middle reaches of Heihe River Basin (Northwest China) from 1985 to 2013; [Evolution du système aquifère influencé par les activités anthropiques dans les cours moyens du bassin versant de la rivière Heihe (Nord-Ouest de la Chine) entre 1985 et 2013]; [Evolução do sistema de águas subterrâneas do trecho central da Bacia Hidrográfica do Rio Heihe (Nordeste da China) sob o impacto de atividades antropogênicas entre 1985 e 2013]; [Evolución de un sistema de agua subterránea bajo los impactos de las actividades humanas entre 1985 y 2013 en la parte media de la cuenca del río Heihe (Noroeste de China)]

Investigation of the evolution of the groundwater system and its mechanisms is critical to the sustainable management of water in river basins. Temporal and spatial distributions and characteristics of groundwater have undergone a tremendous change with the intensity of human activities in the middle reaches of the Heihe River Basin (HRB), the second largest arid inland river basin in northwestern China. Based on groundwater observation data, hydrogeological data, meteorological data and irrigation statistical data, combined with geostatistical analyses and groundwater storage estimation, the basin-scaled evolution of the groundwater levels and storage (from 1985 to 2013) were investigated. The results showed that the unbalanced allocation of water sources and expanded cropland by policy-based human activities resulted in the over-abstraction of groundwater, which induced a general decrease in the water table and groundwater storage. The groundwater level has generally fallen from 4.92 to 11.49 m from 1985 to 2013, especially in the upper and middle parts of the alluvial fan (zone I), and reached a maximum depth of 17.41 m. The total groundwater storage decreased by 177.52 × 108 m3; zone I accounted for about 94.7 % of the total decrease. The groundwater balance was disrupted and the groundwater system was in a severe negative balance; it was noted that the groundwater/surface-water interaction was also deeply affected. It is essential to develop a rational plan for integration and management of surface water and groundwater resources in the HRB. © 2016, Springer-Verlag Berlin Heidelberg.