Geosphere and Physical Geography: Relief, Climate, Soils, Water Balance and Natural Hazards
What this domain tests
In the Hamburg Abitur the physical-geography strand asks you to explain landform and climate systems as process chains, not as lists. Typical tasks give a space (Norddeutschland, a coastal plain, an alpine or Mediterranean comparison area) and demand a budget-based argument: which fluxes dominate, which stores change, and what follows for hazard exposure. Expect to combine a map or profile with climatic data and to reason quantitatively about water balance.
Core rules and concepts
- Relief as a system: endogenic structure (uplift, subsidence, salt tectonics in the North German Basin) sets the frame; exogenic processes (glacial and periglacial sculpture, fluvial erosion, marine abrasion, aeolian transport) shape it. The North German Plain is a young glacial landscape: ground and end moraines, outwash plains (Sander), glacial valleys (Urstromtäler), and Geschiebemergel till control drainage and soil texture.
- Water balance: P = ET + R + ΔS (precipitation = evapotranspiration + runoff + storage change). Actual evapotranspiration is limited by available water; potential evapotranspiration by energy. A positive climatic water balance means P > PET; a negative one means a deficit that must be met from soil storage or irrigation. Sandy outwash soils have low field capacity, so deficits hit faster even where annual P is adequate.
- Soil formation factors (Jenny): climate, organisms, relief, parent material, time - plus human influence. Podzolisation requires acidic litter and downward percolation; this is why Podzols sit on quartz-rich sand, while Geschiebemergel (calcareous till) supports Luvisols and Cambisols. Gley and pseudogley record waterlogging versus perched water.
- Hazards as risk: Risk = hazard × exposure × vulnerability. Physical probability alone is not an answer; you must name who or what is exposed and why vulnerability differs (building standards, warning systems, land use on floodplains).
Worked example with reasoning
Task: explain why a low-lying North Sea coastal area with rising sea level needs more than higher dikes. Reasoning chain: (1) mean sea level rise plus storm-surge frequency shift the hazard; (2) subsidence from peat oxidation and groundwater withdrawal raises relative sea level; (3) the hinterland drains by gravity, so dike raising alone increases pumping dependence; (4) therefore adaptation combines dike reinforcement, retention areas (Polder), managed realignment (de-poldering to rebuild marsh as wave attenuation), and land-use restriction in the most exposed zones. Conclusion ties risk components together rather than claiming "dikes are the solution".
Traps that cost marks
- Naming processes without the controlling variables (grain size, slope, vegetation cover, permafrost).
- Using potential evapotranspiration as if it were real water loss.
- Describing soils by colour instead of by diagnostic processes.
- Confusing hazard magnitude with disaster impact.
- Ignoring timescales: a glacial landform and a storm surge operate on completely different clocks.