Rivers and Coastal Processes
River discharge (volume of water in a river at a specific time and place) can increase or decrease based on several factors. High precipitation, melting ice caps, steep gradients, and urbanisation all increase discharge. Meanwhile, low rainfall, dams, and vegetation can decrease it.
Hydrographs show how rivers respond to rainfall. They display the relationship between rainfall and discharge over time, with the lag time (delay between peak rainfall and peak discharge) affected by drainage basin size, vegetation cover, valley steepness, and soil type.
💡 The lag time on a hydrograph tells you how quickly a river responds to rainfall - shorter lag times often mean higher flood risks!
Coastal landforms develop differently depending on rock formations. Concordant coastlines have rock bands parallel to the wave front, creating similar erosion rates. Discordant coastlines have alternating hard and soft rock at right angles to the sea, forming distinctive headlands and bays. Sand dunes form when wind carries sand inland, with embryo dunes developing first before eventually becoming mature dunes, while dune slacks form where the water table is exposed.








