Magical model passes the acid test

Posted on September 26, 2009

Over the last 150 years the fallout from industrial emissions (acid rain) has increased levels of acidity in inland waters, especially in Europe andNorth America, with serious consequences for ecosystem health.  Efforts are underway to reverse the effects of acidification, but in order to assess their success it’s important to compare present-day acid levels with original “natural” concentrations.  Pre-industrial acid levels in lakes are commonly estimated using a mathematical model (MAGIC – Model of Acidification of Groundwater in Catchments).  Although powerful, MAGIC requires many types of input data, on hydrology, local land use, rainfall, runoff and lake water quality, which limits its application.  To address this problem, Swedish researchers have developed a much simpler model that requires data only on present-day concentrations of base cations (Ca, Mg, Na, K), sulphate and chloride.  The new model was calibrated to pre-industrial reference values predicted by MAGIC for 95 Swedish lakes, and has a high level of reliability. 

Reference:  Erlandsson, M., Folster, J., Wilander, A. & Bishop, K.  2008.  A metamodel based on MAGIC to predict the pre-industrial acidity status of surface waters.  Aquatic Sciences 70, 238–247.