The U.S. has more than 87,000 dams greater than six feet high (and two million overall). While many dams continue to provide benefits such as flood control, irrigation, and water supply, for other dams the cost of maintenance or the negative effects on communities, fish, and tribes justifies their removal.
Dam owners and regulators decide whether to remove a dam by weighing many factors including: the cost of removal and the ability to replace any lost power generation against avoided long-term maintenance; safety concerns; benefits to endangered fish populations; increased recreational and commercial fishing; and restoration of cultural values of nearby tribes.
By 2020, roughly 70% of dams will be more than 50 years old, inviting us to reconsider the value to the public of long-term investments in this infrastructure.
Answer:
Both the Enlightenment and the Industrial Revolution were social processes that led to great changes in the societies of the time. Thus, the Enlightenment led to the adoption of liberal ideologies and greater exercise of rights by the societies of the time, which implied a limit to the powers of the authoritarian governments of the time; While the Industrial Revolution, in turn, led to the adoption of automated production processes that made most of the population begin to reside in urban centers, abandoning rural life.
These two processes, which occurred continuously, greatly modified the social composition of the societies of the time. Thus, European societies became eminently urban, with more combative populations and with a greater awareness of their rights and of the limits to the power of the rulers. This caused conflicts between the liberal sectors and the conservative sectors of the time to begin to occur, giving way to revolutions such as the American Revolution or the French Revolution.
The effect that the silk road had on trade was massive; The Silk road brought people far across Asia and Europe bringing different aspects of their culture with them.
