I am working at FAO on a project on forest degradation

d. The volume of soil lost, from the estimated catchment area (here 1 km2) is converted to a volume per square meter : 3000 / 1,000,000 = 0.003 m3 / m2. e. The volume per square meter is converted to tonnes per hectare, using an estimated soil bulk density value of 1.3 t/ m3: 0.003 * 1.3 * 10,000 = 39 t/ha ................
................