Hydroperiod map of Danube Delta for 2016/2017 and its accompanying INSPIRE metadata XML file

The annual hydroperiod of wetlands, which is affected by global trends and human activities, is a critical
ecological parameter that shapes aquatic plants’ and animals’ distribution and determines available habitat
for many of the living organisms. Thus, its estimation is useful for the sustainable management of wetlands.

The hydroperiod map of Danube Delta is named: "Danube_Delta_Hydroperiod_from_1st_Sept_2016_to_31st_Aug_2017_using_Sentinel_2_inundation_maps.tif". The pixel values range from 0 to 365 (or 366 for leap years) and denote the number of days a pixel is inundated within a year. The map is generated by interpolating satellite-derived inundation maps falling within the period indicated in its filename.

The interpolation approach is the following: For two dates separated by n days, the occurrence of water is compared. If a pixel is inundated on both dates, then it is assumed inundated for n-days. If a pixel is not inundated on both dates, then it is assumed inundated for n/2 days. In the hydroperiod map, the total number of inundation days per pixel is determined by accumulating the inundated days throughout the desired time period.