OCR A Level Earth's support systems: Lesson 4 Water Balance

OCR A Level Earth's Life support systems : first four lessons: Water

This four-lesson sequence on Earth’s Life Support Systems (Water) is designed specifically for OCR A Level Geography and provides a clear, structured introduction to one of the core components of the global hydrological system. Students begin by exploring the importance of water as a life support system, developing understanding of its role in sustaining ecosystems, human populations, and economic activity at a range of scales. They then build detailed knowledge of the global distribution of water stores, examining the proportions held in oceans, ice, groundwater, and the atmosphere, and the implications of uneven distribution. The sequence progresses into a more systems-based understanding of water transfers and interactions between stores, enabling students to grasp key processes within the hydrological cycle and how these operate as an integrated system. Finally, learners apply their knowledge through the concept of water balance, interpreting inputs, outputs, and storage changes across different environments and developing the analytical skills required for A Level assessment. Carefully sequenced and exam-focused, this unit strengthens both conceptual understanding and application, equipping students with the knowledge and skills needed for success in OCR A Level Geography.