Worked solution
Extreme summer weather in the UK is characterized by prolonged heatwaves and droughts, punctuated by sudden, intense convective rainstorms. These weather patterns have significant, contrasting impacts on UK physical landscapes. Firstly, during prolonged hot and dry periods, river discharge drops significantly. This lack of water reduces the river's energy, meaning that erosion ceases and deposition of fine sediment becomes the dominant process. At the same time, high temperatures cause clay-rich soils and rocks to dry out, shrink, and crack, which is a key form of physical weathering. Secondly, when intense summer rainstorms occur on dry, hard-baked soils, the ground is highly impermeable due to low infiltration capacity. This results in rapid surface runoff, leading to sudden flash flooding in river valleys. The resulting high-energy river flows cause rapid lateral and vertical erosion through hydraulic action and abrasion, dramatically altering river channels and transporting massive volumes of sediment downstream. Thirdly, slope stability on upland slopes and coastal cliffs is severely affected. Intense rain filling deep desiccation cracks increases pore water pressure, destabilizing the slope and triggering sudden mass movement events such as slumping, rockfalls, or debris flows. In conclusion, while dry summer weather temporarily reduces some active processes like river erosion, its true impact is that it primes the landscape for highly destructive, rapid geomorphic changes when sudden, intense summer storms occur. Therefore, the combination of these extreme summer conditions has a highly significant, dynamic impact on UK physical landscapes.
Marking scheme
AO2 (4 marks) and AO3 (4 marks) breakdown. Level 1 (1-3 marks): Demonstrates isolated knowledge of physical processes or weather types. Explanations are brief or descriptive with limited application to the landscape. Level 2 (4-6 marks): Demonstrates good understanding of how extreme summer weather (both dry periods and storms) affects physical landscapes (such as clay cracking, runoff, mass movement, or river discharge). Some assessment of the impacts is present. Level 3 (7-8 marks): Demonstrates detailed understanding, showing clear application to both the dry and wet phases of summer extremes. Offers a well-supported, logical assessment of how these contrasting conditions interact to drive rapid, significant landscape changes.