Article Figures & Data
Figures
1. On calm hot days a depression Is formed above the city which Is filled from the sides.
2. Continual increase of air pollution as well as of temperature in direction of the center of the city.
3. The Increase of air pollution Is interrupted by the greens, and the air is filtered.
4. Interruption of the temperature rise, cooling down of the air by the greens, providing the built-up areas with cool, salubrious air.
5. Diagram showing the balancing of temperatures between the greens and the built-up areas. Filtering of the falling air by trees. Cooler and cleaner air flows to the built-up centers.
6. Effects of concentrically laid-out greens on temperature.
7. On windy days. Diagram showing the direction of the main air currents and pollution of the town.
8. Filtering action of the greens.
Tables
Average Max. of average Min. abaolute Maximum Big cities 147 000 379 000 49100 4 000000 Small towns 34 300 114000 5 900 400 000 Country places 9 500 66 500 1 050 336 000 Coastal areas 9 500 33 000 1 560 150000 Mountains: 500-1000 m 5000 36 000 1 390 155 000 1000-2000m 2130 9 830 450 37 000 above 2000 m 950 5 830 160 27 000 Ocean 940 4 680 840 39 800 (A. Landsberg) Average values of air pollution have been found by Reifferscheldt in Germany shortly after the end of the war to be Big cities Country Kernels 200 000 8000 per cm3 Dust particles 270 7-10 Surface covered by building 19.9% Streets and squares for traffic 9.0% Green spaces 2.0% Agricultural grounds 43.0% Forestry grounds 18.0% Ponds, rivers, etc. 3.1 % Other spaces 3.7%