Rivers can either be rain-fed or snow-fed. And most of the bigger civilizations of the past were located on the river banks.
The climate of the region is temperate, but nearby there is a mountain range which has an average altitude of around 3500 metres. For the time being, let us assume that the planet is a earth-like planet with the diurnal cycles, the temperature zones and the land-water distribution is similar to that of earth. There is a single natural satellite circling around the planet, with it's size being twice that of our moon, while the distance is around 1.6 times that of the distance between earth and moon. The seasonal changes are slightly longer than that of the earth due to a larger orbit(Let's assume around 400 days to be a solar year).
The region is a peninsular region where the river empties into a sea. The salinity of the sea makes it non-drinkable.
Given these constraints, how can the culture, pantheon and prioritized invention of a civilization which has developed on the banks of this region be impacted by a change in the following factors(keeping other factors constant):
- Source of the river being from the mountain or from other sources(i.e. rain-fed or snow-fed),
- Flood cycle (Please also elucidate on the cause of flood cycle changes),
- Mineral constitution of the land at the source of the river?
EDIT: Narrowing the context of the question, is their any behavioural trends in the pantheon and the technological advancement of a civilization, dependent on the aforementioned factors, keeping the other factors and the previously stated constraints unchanged? If so, what is the correlation?