Key Idea: Topic 4.1 is about how **water moves as a global system** (hydrological cycle), how it is stored and transferred (stores + flows), how **drainage basins** work as open systems, and why water is crucial for **climate regulation**.
🔁 Hydrological cycle (key processes)
Energy marks: mention **solar energy drives evaporation** (endothermic) and **condensation releases heat** (exothermic).
🏦 Stores, flows & residence time
🛁 Drainage basins as systems
If asked about impacts (e.g., dams/land-use change), explain system-wide effects: **flow rate, sediment, nutrients, oxygen, biodiversity** downstream.
🌡️ Water and climate regulation (why water is Earth’s thermostat)
1) Name 4 water-cycle processes. 2) Define residence time. 3) Explain a drainage basin as an open system. 4) Give 3 ways water regulates climate.