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A-Level Tropical Climates and Drainage Basins (Cluster 2)

how climatic and hydrological systems interconnect across tropical regions, spanning atmospheric circulation and rainfall through to the movement of water and flooding

What the syllabus expects

• Grouping tropical locations into climate zones by their temperature and rainfall: the humid tropics (tropical monsoon Am, tropical savanna Aw, tropical rainforest Af) and the arid tropics (tropical desert BWh, sub-tropical steppe BSh)
• Consistently high temperatures are what most distinguishes the tropics
• Rainfall totals differ between the humid and arid tropics
• Rainfall varies seasonally across different parts of the tropics
• A high angle of incidence produces surplus heat and raises temperatures in the tropics
• Surplus heat drives the atmospheric circulation of the Hadley cells
• Circulation within the Hadley cells shapes tropical rainfall patterns
• The seasonal migration of the Hadley cells also affects where and when it rains in the tropics
• The distribution of heat over land and sea drives the summer and winter monsoon circulations across humid tropical Asia, with knock-on effects on rainfall
• The atmospheric and surface conditions needed for tropical cyclones to form, and how these storms affect rainfall
• The three phases of the El Nino Southern Oscillation (ENSO) and the rainfall changes each brings over the tropical Pacific: the El Nino, neutral and La Nina phases
• Water enters the drainage basin system through precipitation and snowmelt
• Water leaves the drainage basin system through evapotranspiration and river discharge
• The balance of input against output in tropical basins varies over time and space owing to natural factors
• Water is held within the drainage basin as channel storage, groundwater storage, interception storage and soil moisture storage
• Storage in tropical basins varies over time and space because of both natural and human factors
• Water travels through the basin along pathways including baseflow, channel flow, infiltration, overland flow, percolation and throughflow
• These pathways in tropical basins vary over time and space due to natural and human factors
• Fluvial floods happen when peak discharge tops bankfull discharge and spills over onto normally dry land nearby
• Across the humid tropics, fluvial flooding stems from a combination of natural and human causes
• Fluvial floods bring both positive and negative impacts to places
• The effects of fluvial floods differ from place to place
• Different groups of people experience flood effects unequally because their vulnerability differs
• The strengths and weaknesses of the various strategies for managing fluvial floods
• Flood management strategies achieve differing levels of success
• How far humans are actually able to control whether fluvial floods occur

More A-Level H2 Geography topics

Environment and Resources (Cluster 1) · Development and the Global Economy (Cluster 1) · Landforms in the Tropics (Cluster 2) · Cities in a Sustainable Future (Cluster 3) · The Future with Climate Change (Cluster 3) · Fieldwork (Cluster 4) · all of A-Level H2 Geography