The GWP maps show different water coverage categories which represent how often a location (pixel) was detected as open surface water. Dark blue color show lakes and rivers which can be considered as permanent open water, red color represents pixel which were rarely water over the year. Be aware that lake ice was not classified as open surface water. Therefore, e.g. Northern hemisphere lakes, indirectly visualize how long a lake was ice free.

Information about extent and dynamics of open surface water are essential for climate research, hydrological applications, flood prediction and water management. Climate and environmental change as well as water management are influencing the characteristics and duration of surface water around the globe. Therefore, precise information about the different open surface water parameters and their development over time are of high importance for various research fields.

The Global WaterPack is a dataset containing information about open surface water cover parameters on a global scale. The water detection is derived from daily, operational MODIS datasets for every year since 2003. The negative effects of polar darkness and cloud coverage are compensated by applying interpolation processing steps. Thereby, a unique global dataset can be provided that is characterized by its high temporal resolution of one day and a spatial resolution of 250 meter. Furthermore, reliability and observation layers provide additional information on the quality of each Global WaterPack pixel at daily, monthly, and yearly temporal scale.