Blue and Green Water
Trying to link complexity theory to environmental issues I found the following at the Stockholm Resilience Center, Part of Stockholm University in their resiliency dictionary. http://www.stockholmresilience.org/research/resilience-dictionary.html
Blue and green water: ‘Blue water´ is the liquid water in rivers, lakes and ground water. ‘‘Green water´ is the water that feeds the system as rain and forms soil moisture that is absorbed by plants (and then exhaled as vapour flow). When discussing the water needed to produce food for an expanding human population we tend to neglect the green water flows even though most food production comes from rain-fed farming, not least in hunger and poverty stricken areas with rapid population growth.
Water Issues 