As the speed of river water slows what is deposited

Sediment. So the river picks up sediment when it is moving quickly and deposits it when it slows down (or when there is a bend in the river).

Well, both latitude and intensity of light affect temperature because, the higher the light intensity, the higher the temperature and since latitude is the measure of how close you are to the equator, then the closer to the equator you are, the higher the temperature is.