Christianity is the largest group
Hi. "Tidal wave" suggests a wave associated with the ebbs and flows related to the relative positions of the earth, moon and sun. These rises and falls relative to mean sea level are periodic and easily predictable. But the enormous wave generated by an earthquake is probably even less easy to predict than an earthquake and of no regular (that is, periodic) recurrence that anyone knows of. But I think "tsunami" is not too bad a name for such earthquake-generated waves as tsunami does not suggest any strong link with the relative positions of the earth, moon and sun.
Religious and ethnical problems.
It was one of the largest empires of the world with many different ethnicities. The problem was to unite people under one rule.
Another problem was communication. It was hard to transfer knowledge and news to all parts of the empire because it was too large.
The most important economic goal that was associated with
the construction of the Three Gorges Dam the production of the hydroelectric
power. The water was going to be used as clean and renewable resource . Hydroelectric
is very clean since it does not emit any greenhouse gases when producing this
type of energy.