Characterizing 19 thousand Chinese lakes, ponds and reservoirs by morphometric, climate and sediment characteristics

•Vulnerability to algal blooms differ among lakes, despite a similar nutrient load.•We classified 19,536 lakes, including ponds and reservoirs, in China.•Eastern lakes are deeper and warmer than western lakes.•Eastern lakes seem typically most vulnerable to algal blooms with few exceptions.•Most vulnerable lakes to algal blooms are located in areas with eutrophication. Chinese lakes, including ponds and reservoirs, are increasingly threatened by algal blooms. Yet, each lake is unique, leading to large inter-lake variation in lake vulnerability to algal blooms. Here, we aim to assess the effects of unique lake characteristics on lake vulnerability to algal blooms. To this end, we built a novel and comprehensive database of lake morphometric, climate and sediment characteristics of 19,536 Chinese lakes, including ponds and reservoirs (>0.1 km2). We assessed lake characteristics for nine stratification classes and show that lakes, including ponds and reservoirs, in eastern China typically have a warm stratification class (Tavg>4 °C) and are slightly deeper than those in western China. Model results for representative lakes suggest that the most vulnerable lakes to algal blooms are in eastern China where pollution levels are also highest. Our characterization provides an important baseline to inform policymakers in what regions lakes are potentially most vulnerable to algal blooms. [Display omitted]