I have to wonder if this result is due to increased evaporation (from the dam surface) or increased transpiration (from non-irrigated and irrigated fields). With oxygen isotope analysis the two can be distinguished.
This type of analysis reveals that trees are responsible for about 80% of all terrestrial rainfall.[1] In contrast to man-made desalination facilities, this water falls freely as rain instead of being owned and controlled.
Global deforestation/desertification is perversely convenient for those interests vying to control water, since in a very real way it eliminates the competition.
1.1 x 10^14 cu m of water falls on land per year. [0]
5 x 10^14 cu m falls yearly on the earth [1]
80,000 cubic meters is said to be lost to this effect [2].
[0]http://voices.nationalgeographic.com/2012/03/14/are-we-runni... [1]http://hypertextbook.com/facts/2008/VernonWu.shtml [2]http://www.jordantimes.com/news/local/80000-cubic-metres-wat...