Water and Carbon Cycles

These flashcards cover key concepts from the lecture notes related to water and carbon cycles, focusing on the impacts of land use changes, urbanization, and deforestation.

What is the effect of terracing on hillsides in relation to water movement?

Terracing on hillsides stops the movement of water downhill and subdues hydrographs.

What are plough pans and their impact on soil?

Plough pans are impermeable smears in the subsoil caused by ploughing wet soils that inhibit percolation, leading to greater surface flows.

How does urban growth affect hydrographs?

Urban growth leads to large impermeable surfaces like roads which create flashy hydrographs by promoting quick water runoff.

What role does afforestation play in flood management?

Afforestation increases interception and infiltration of water, slowing down its progress to the river and subduing changes in discharge.

What is the impact of deforestation on stream flow?

Deforestation leads to increased stream flow due to reduced water use by new vegetation and less evaporation returning to the atmosphere.

How does water abstraction affect river discharge?

Water abstraction reduces the base flow, causing more water to reach the channel before it reaches bankfull capacity.

What percentage of deforestation can significantly affect stream flow?

Studies have shown significant changes occur with 50 to 100 percent of a basin deforested.

What are some consequences of urbanization in relation to gardens?

In urban areas, there has been a loss of front gardens for paved drives, which has led to a loss of vegetated area, exacerbating drainage issues.