One of the main reasons that the Three Gorges dam was built was to prevent flooding further downstream. The need for a dam was highlighted in 1954 when people were killed as a result of flooding of the Yangtze River.
Arab Spring refers to the democratic uprisings that arose independently and spread across the Arab world in 2011. The movement originated in Tunisia in December 2010 and quickly took hold in Egypt, Libya, Syria, Yemen, Bahrain, Saudi Arabia, and Jordan.
The term Arab Spring is an allusion to the Revolutions of 1848, which is sometimes referred to as the Springtime of Nations, and the Prague Spring in 1968. In the aftermath of the Iraq War it was used by various commentators and bloggers who anticipated a major Arab movement towards democratization.