This dataset comprises historical orthophotos from the 1980s to 1989, derived from aerial surveys carried out by the National Geographic Institute (NGI). The ground sample distance (GSD) of the images is 10 cm. The mosaics were created using aerial photography campaigns dating from 1989. The original photographs were digitised and orthorectified in the Lambert 2008 coordinate system. The spatial coverage for each year corresponds to the areas for which photographs were available. High-resolution data can be ordered via https://shop.ngi.be/fr/photos-aeriennes/

Annual temperature extremes given in number of days: 1/ Total number of heatwaves occurring once in 20 years; 2/ Maximum length of the heatwaves occurring once in 20 years; 3/ Hot days: Mean annual number of days with maximum temperature > 25°C; 4/ Tropical days: Mean annual number of days with maximum temperature > 30°C; 5/ Frost days: Mean annual number of days with minimum temperature < 0°C. Heatwaves are defined according to the Royal Meteorological Institute of Belgium when the maximum temperature in Uccle is >= 25°C during at least 5 consecutive days, during which at least 3 days the maximum temperature is >= 30°C. The temperature extremes are available for the present target year 1975, which corresponds to the middle of the 30-year period 1961-1990.

Annual and seasonal precipitation indices given in number of days: 1/ Wet days: Number of days with precipitation > 0.1 mm/day for winter, autumn, spring, summer; 2/ Dry days: Number of days with precipitation < 0.1 mm/day for winter, autumn, spring, summer; 3/ Average length of dry spells: Mean duration of minimum three consecutive days with precipitation < 0.1 mm/day; 4/ Maximum length of dry spells: Longest period of minimum three consecutive days with precipitation < 0.1 mm/day, occurring once in 20 years. The precipitation indices are available for the future target year 2085, which corresponds to the middle of the 30-year period 2071-2100, and for mean and high impact scenarios corresponding respectively to the 50th, and 5th or 95th percentiles of the change factors.

Summer and winter mean relative humidity given in %. The relative humidity fields are available for the present target year 1975, which corresponds to the middle of the 30-year period 1961-1990.

Annual temperature extremes given in number of days: 1/ Total number of heatwaves occurring once in 20 years; 2/ Maximum length of the heatwaves occurring once in 20 years; 3/ Hot days: Mean annual number of days with maximum temperature > 25°C; 4/ Tropical days: Mean annual number of days with maximum temperature > 30°C; 5/ Frost days: Mean annual number of days with minimum temperature < 0°C. Heatwaves are defined according to the Royal Meteorological Institute of Belgium when the maximum temperature in Uccle is >= 25°C during at least 5 consecutive days, during which at least 3 days the maximum temperature is >= 30°C. The temperature extremes are available for the future target year 2085, which corresponds to the middle of the 30-year period 2071-2100, and for mean and high impact scenarios corresponding respectively to the 50th and 95th percentiles of the change factors.

This dataset comprises historical orthophotos from the 2010s to 2019, derived from aerial surveys carried out by the National Geographic Institute (NGI). The ground sample distance (GSD) of the images ranges from 25 to 100 cm. The mosaics were created using aerial photography campaigns dating from 2010, 2011, 2012, 2013, 2014 and 2015. The original photographs were digitised and orthorectified in the Lambert 2008 coordinate system. The spatial coverage for each year corresponds to the areas for which photographs were available. High-resolution data can be ordered via https://shop.ngi.be/fr/photos-aeriennes/

Annual, summer and winter mean potential evapotranspiration given in respectively mm/year and mm/3 months and based on the Penman-Monteith definition. The potential evapotranspiration fields are available for the present target year 1975, which corresponds to the middle of the 30-year period 1961-1990.

This dataset comprises historical orthophotos from the 1960s to 1969, derived from aerial surveys carried out by the National Geographic Institute (NGI). The ground sample distance (GSD) of the images ranges from 10 to 50 cm. The mosaics were created using aerial photography campaigns dating from 1961, 1966 and 1969. The original photographs were digitised and orthorectified in the Lambert 2008 coordinate system. The spatial coverage for each year corresponds to the areas for which photographs were available. High-resolution data can be ordered via https://shop.ngi.be/fr/photos-aeriennes/

This dataset comprises historical orthophotos from the 1990s to 1999, derived from aerial surveys carried out by the National Geographic Institute (NGI). The ground sample distance (GSD) of the images ranges from 25 to 100 cm. The mosaics were created using aerial photography campaigns dating from 1995, 1997, 1998 and 1999. The original photographs were digitised and orthorectified in the Lambert 2008 coordinate system. The spatial coverage for each year corresponds to the areas for which photographs were available. High-resolution data can be ordered via https://shop.ngi.be/fr/photos-aeriennes/

This dataset comprises historical orthophotos from the 1950s to 1959, derived from aerial surveys carried out by the National Geographic Institute (NGI). The ground sample distance (GSD) of the images is 50 cm. The mosaics were created using aerial photography campaigns dating from 1951, 1952 and 1954. The original photographs were digitised and orthorectified in the Lambert 2008 coordinate system. The spatial coverage for each year corresponds to the areas for which photographs were available. High-resolution data can be ordered via https://shop.ngi.be/fr/photos-aeriennes/