Answer:
<u><em>River valley civilizations</em></u>
Explanation:
They were centred around various river valleys as their main source of livelihood and the flourished only due tiote river valley on which they were based. Like the harappan in Indus Valley, The yellow river (Huang He), the Mesopotamia around Tigris and Euphrates and the egyptian Nile.
There are many different ways to measure weather, for example there is a barometer, rain gauge, wind vane, anemometer, weather balloon, compass, and a weather satellite. Your welcome.
- Amber
Radiometric dating should be what they use
