In order to create a hydroelectric power plant, you need water, hence the prefix hydro-. Most times, people use dams to block the water, which in a way stores it. When you need to produce electricity, you release some of the water which flows through a turbine making it spin, which then activates a generator to produce electricity.
1. Laying eggs on land reduces the chances of the eggs being predated on by predators in the seas and oceans.
2. Temperatures are critical in the development of the yolk into an embryo and full turtle. Temperatures even determine the sex of the developing turtles. Land heats up more than water hence promotes faster development hence increases the survival of the offsprings.
Deforestation is not a natural change.