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.
There are <span>Divergent boundaries which are areas where plates move away from each other, forming either mid-oceanic ridges or rift valleys.
There are Convergent boundaries which are areas where plates move toward each other and collide.
And there are Subduction zones which occur where an oceanic plate meets a continental plate and is pushed underneath it. Subduction zones are marked by oceanic trenches
</span>
I hope this helps. I know it was pretty late, sorry about that.
India - Deccan Plateau
Pakistan - Khyber Pass
Sri Lanka - Mount Pidurutalagala
Nepal - Mount Everest
Carrying capacity is the theoretical maximum rate of population growth. It is the maximum population size that the environment can sustain. This means that it is the maximum number of individuals of given species that the evironment's resources can sustain. It is the population size that can have enough water, food, habitat and other resources in order to survive and live.
