World Environmental Health index

World Environmental Health index (WEHI) is a method of quantifying and numerically marking the overall health of the Environment of a planet. The result of the species census is analyzed and compared to records of the planet when it was pristine (prior to the arrival or development of sentient lifeforms) if possible or to estimations what certain environments would be without the interference of sentient liforms.

One aspect of the analysis is to determine how close an environment is to being in a dynamic balance. In many cases that dynamic balance is given more weight than the possible existence of species that are not native to a biome.

While the overall index is given in the form of percentage from 0 to 100, typically for non pristine planets anywhere above a 95% is acceptable. Only pristine planets receive a score of 100%. Conversely a planet that previous to the intervention of sentient life was unable to sustain a Biosphere will receive a 0 even if it has been sucessfully terraformed. A score of 0 will also be given when nothing remains of the original biosphere (normally for that to happen would mean that the planet had been P bombed. Agricultural planets developed prior to 3250 typically had a WEHI less than 10%. Those agricultural planets founded after 3250 are encouraged to leave at total of 20% of the land area in it's natural state.