Transform: The plates slide past each other, one going forwards, the other going back, kind of grinding each other. A Transform Boundary is also a fault, so it causes Earthquakes mostly.
Convergent: When two plates collide with each other. They form subduction mostly and trenches. They can also create volcanoes or volcanic islands.
Divergent: When two boundaries move away from each other. They form rift valleys, mountain ranges
If the region rises in population it will most likely cause a bigger scarcity in water, which may lead to a drought. A drought can ruin crops and leave land dry.
I would say the topic of such a study would be paleomagnetism and perhaps its effect on plate tectonics because when the seafloor spreads at the mid-ocean ridges, magnetized stripes of rock, symmetrical on either side of the trench form and they record changes in the earth's magnetic poles at certain times so can be dated to help show the rate of spreading of the seafloor at these locations.
Yangtze River another name for the river is "China's Sorrow".
