Spatial and seasonal variations of trace metals in a karst water system in Central China and implications

Based on monitoring (2011.7-2012.6) of a karst water system in NE Sichuan, Central China, we presented monitoring results of the spatial and seasonal variations of metals Ca, Mg, Sr and Ba in cave waters and surface river water. Three sites were chosen for the monitoring. SLPB and LZLY are two in-cave sites and HS represents the Nuoshui River. SLPB is the deepest point of the cave, where an underground river emerges. There is fast dripping water in winter and the drip water becomes a waterfall in summer. LZLY is the pool. The drip water at SLPB, pool water at LZLY and surface river water at HS were collected once a month from July 2011 to June 2012. At each site, about 500 ml of waters were sampled with pre-cleaned polypropylene bottles (Nalgene), acidified in site to pH