Impact of recent climate variability on an aquifer system in north Belgium

The last decade it has been realised that climate and global change can (and very likely will affect) groundwater reserves. This will have impact on both the economical (groundwater exploitation) and ecological (ecosystems) aspects of aquifer systems. A key issue is the intrinsic variability in hydrodynamics due to natural fluctuations of meteorological conditions. In this paper the results of a modelling study are presented that reconstructs the hydrodynamic evolution of the important Neogene aquifer system in North-East Belgium, between 1833 and 2005. Boundary conditions are defined on a monthly basis. The results show that besides the yearly seasonal fluctuations also multi-year to decadal variations occur. These are especially important in the topographic higher regions like on the Campine plateau and the Campine cuesta, and can severely affect local groundwater dependent ecosystems as found in some protected areas and nature reserves. The same cyclicity is recognized in the intensity and extent of seepage of deep Neogene groundwater in the Nete basin

Analysis of the groundwater resource decline in an intramountain aquifer system in Central Iran

The Shahrekord aquifer is located in an intramountain basin in Central Iran (90 km SW of Isfahan) and is the main resource of irrigation water for the intensively developed agriculture in the Shahrekord Plain. Early exploitation of the aquifer started back around 1950 but has intensified severely during the last decades. Irrigation water is provided by three means: spring water is tapped, water is pumped from around 650 wells and in historic times more than 100 karizes (or ghanats, deep underground channels that drain the water table and are accessed by shafts) were constructed and provide an additional source of water. However, groundwater levels have declined severely during the last decade, and although systematic piezometric monitoring already started in 1984, it stayed unclear whether the declining trend is related to increased water demand and exploitation or is due to climatic reasons, as around 2000 a severe drought lasted for three years. In this paper, exploitation and precipitation data are combined with the measured piezometric levels to analyse their relationship and help to understand the observed trend in declining groundwater storage. This aquifer is an example of a system that can easily deliver large amounts of groundwater because of a high transmissivity and considerable thickness, but has, for climatic reasons, a limited recharge. This imbalance makes the present level of exploitation unsustainable