Articles | Volume 10, issue 3
Review article
24 Aug 2018
Review article |  | 24 Aug 2018

Diversity II water quality parameters from ENVISAT (2002–2012): a new global information source for lakes

Daniel Odermatt, Olaf Danne, Petra Philipson, and Carsten Brockmann

Abstract. The use of ground sampled water quality information for global studies is limited due to practical and financial constraints. Remote sensing is a valuable means to overcome such limitations and to provide synoptic views of ambient water quality at appropriate spatio-temporal scales. In past years several large data processing efforts were initiated to provide corresponding data sources. The Diversity II water quality dataset consists of several monthly, yearly and 9-year averaged water quality parameters for 340 lakes worldwide and is based on data from the full ENVISAT MERIS operation period (2002–2012). Existing retrieval methods and datasets were selected after an extensive algorithm intercomparison exercise. Chlorophyll-a, total suspended matter, turbidity, coloured dissolved organic matter, lake surface water temperature, cyanobacteria and floating vegetation maps, as well as several auxiliary data layers, provide a generically specified database that can be used for assessing a variety of locally relevant ecosystem properties and environmental problems. For validation and accuracy assessment, we provide matchup comparisons for 24 lakes and a group of reservoirs representing a wide range of bio-optical conditions. Matchup comparisons for chlorophyll-a concentrations indicate mean absolute errors and bias in the order of median concentrations for individual lakes, while total suspended matter and turbidity retrieval achieve significantly better performance metrics across several lake-specific datasets. We demonstrate the use of the products by illustrating and discussing remotely sensed evidence of lake-specific processes and prominent regime shifts documented in the literature. The Diversity II data are available from, and Python scripts for their analysis and visualization are provided at

Short summary
The Diversity II inland water database consists of remotely sensed water quality information for more than 300 lakes in the whole world. It was derived from optical and thermal imagery acquired by the ESA ENVISAT satellite between 2002 and 2012. The database consists of spatially resolved monthly, yearly and 9-year averages for 10 geophysical parameters. Its practical usage is demonstrated by means of several case studies on lake-specific processes and regime shifts.