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

This dataset contains historical orthophoto mosaics based on available aerial photographs covering parts of the Belgian territory. Orthophotos are aerial photographs that have been geometrically corrected (orthorectified) to eliminate distortions caused by terrain relief, lens distortion, and camera tilt. Unlike raw aerial imagery, orthophotos have a uniform scale and accurate geometry, making them suitable for cartography, measurements, and visual analysis. This specific dataset includes historical orthophotos from 1950, 1951, 1952 and 1954, derived from aerial surveys carried out by the National Geographic Institute (NGI). During this period, only analogue aerial photographs are available. The analogue images were scanned at high resolution and orthorectified. The resulting orthophotos were assembled into mosaics and georeferenced in the Lambert 2008 coordinate system. All orthophotos are panchromatic (black and white). The ground resolution (GSD) is 50 cm. The spatial coverage of this dataset is limited to the areas for which aerial photographs were available during the mentioned period. The data can be visualized via the corresponding web services (WMS/WMTS). The orthophotos and the original aerial photographs can be ordered in high resolution via https://shop.ngi.be/nl/luchtfotos/.

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 contains historical orthophoto mosaics based on available aerial photographs covering parts of the Belgian territory. Orthophotos are aerial photographs that have been geometrically corrected (orthorectified) to eliminate distortions caused by terrain relief, lens distortion, and camera tilt. Unlike raw aerial imagery, orthophotos have a uniform scale and accurate geometry, making them suitable for cartography, measurements, and visual analysis. This specific dataset includes historical orthophotos from 1960, 1961, 1966 and 1969, derived from aerial surveys carried out by the National Geographic Institute (NGI). During this period, only analogue aerial photographs are available. The analogue images were scanned at high resolution and orthorectified. The resulting orthophotos were assembled into mosaics and georeferenced in the Lambert 2008 coordinate system. All orthophotos are panchromatic (black and white). The ground resolution (GSD) varies between 10 cm and 50 cm, depending on the sensor used and the surveyed area. The spatial coverage of this dataset is limited to the areas for which aerial photographs were available during the mentioned period. The data can be visualized via the corresponding web services (WMS/WMTS). The orthophotos and the original aerial photographs can be ordered in high resolution via https://shop.ngi.be/nl/luchtfotos/.

This dataset contains historical orthophoto mosaics based on available aerial photographs covering parts of the Belgian territory. Orthophotos are aerial photographs that have been geometrically corrected (orthorectified) to eliminate distortions caused by terrain relief, lens distortion, and camera tilt. Unlike raw aerial imagery, orthophotos have a uniform scale and accurate geometry, making them suitable for cartography, measurements, and visual analysis. This specific dataset includes historical orthophotos from 1989, derived from aerial surveys carried out by the National Geographic Institute (NGI). During this period, only analogue aerial photographs are available. The analogue images were scanned at high resolution and orthorectified. The resulting orthophotos were assembled into mosaics and georeferenced in the Lambert 2008 coordinate system. All orthophotos are panchromatic (black and white). The ground resolution (GSD) is 10 cm. The spatial coverage of this dataset is limited to the areas for which aerial photographs were available during the mentioned period. The data can be visualized via the corresponding web services (WMS/WMTS). The orthophotos and the original aerial photographs can be ordered in high resolution via https://shop.ngi.be/nl/luchtfotos/.

Summer and winter mean wind speed given in m/s. The wind speed fields 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 present target year 1975, which corresponds to the middle of the 30-year period 1961-1990.

Top25Map is a digital version of the NGI’s topographic cartography on a scale of 1:25 000. These images result from the symbolisation of the objects and themes which are present in the topo-geographic inventory of the Belgian territory (ITGI), which is built and kept up-to-date by the NGI. Top25Map contains all usual themes of the NGI’s cartographic products (land use, transport, hydrography, buildings and constructions, relief,…), as well as the map lettering and the toponyms. The Top25Map cartography is appropriate to hiking.

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.

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.