干旱区生态环境知识资源中心

Groundwater is often a critical source of water for municipal, industrial and agricultural uses, especially in and and semi-arid environments. Songnen Plain, located in the central part of northeast China, is such a region, it being an important productive base of commodity grain in this country. In the past two decades, groundwater quality in the region, especially salinization, has deteriorated under natural changes and human activities, and has become a crucial factor restricting sustainable eco-environmental and socio-economic development. In this paper, The Taoer River catchment, situated in the middle of the region, was selected as the study area for the groundwater quality evolution study using hydrochemistry and stable isotopes to obtain a better understanding of the system. Fifty-two groundwater samples were collected with systematic design during the low-water and high-water periods in 2003. A series of comprehensive quality data interpretations, e.g. statistics, ratios of ions and Piper diagrams, together with stable isotope data, have been used to gain an insight into the spatial and temporal variations and evolution laws of groundwater hydrochemistry. The following main hydrochemical processes were identified as controlling the water quality of the groundwater system: weathering-dissolution, evaporation-condensation, ion-exchange reactions and groundwater salinization. This latter process, salinization, is the most important process and is caused by the leaching of superficial or near-surface salts from the saline-alkaline soil into shallow groundwater. Copyright (c) 2006 John Wiley & Sons, Ltd.