DRIER AND DRIER: LAND USE AND WATER SHORTFALLS

摘要

A fellow scientist once asked me "Do you go by the rule of threes or the rule of fives?" Not knowing what he was referring to, I resorted to a standard academic fallback ... I asked him a question: "Under what conditions?" He thought this was very astute and I eventually teased out that the topic of our conversation was the classic, "how long can a human being live without X resources" question. The "rule of threes" and the "rule of fives" referred to how long a human being can live without food, water, shelter, and oxygen. That is, all things taken as equal, how long can the average human survive without air (minutes), shelter from environmental extremes (hours), water (days), and food (weeks). Water Resources IMPACT this month is dealing in a sense with a long-term variation of this question, not for individuals but for cities, towns, and geographic regions and the populations they support.