Hydrosphere

Question 1

Human factors affecting the GLOBAL HYDROLOGICAL CYCLE

Answer 1

DEFORESTATION

1) increases water run off as no trees able to capture rainfall ( decreases evaportranspiraton and therefore decreases cloud formation)
2) no longer tress roots of leaves to intercept perception it can lead to more extreme river levels

IRRIGATION
Takes water from underground stores = therefore lowers the water table
More water is places in canals and reservoirs so increase evaporation and cloud cover

MINING
Silting up of lakes and rivers reduces availability of surface storage
Reduced vegetation leads to increased run off and evaportranspiraton

Question 2

Explain the global hydrological cycle

Answer 2

1) water evaporates from the sea =driven by energy from the sun. As the air rises it condenses to form clouds = because it reaches due point.

2) clouds are blown inwards by process of advection.
Precipitation may fall in form of snow, hail/rain = loss of moisture in clouds and dependant on atmospheric temperatures

3) rainfall is intercepted by plants = soak up moisture as part of photosynthesis and realises it back into atmosphere through evaportranspiraton
4) GROUND WATER FLOW water may infiltrate into soil = slows runoff beavers water runs through tiny gaps in soil particles
5) THROUGH FLOW water can flow overland but if falls as snow (due to cold temp) then it may never reach sea and is trapped as surface storage.
6) percolation also occurs and happens when water is absorbed into bed rock = due to impermeable rock like limestone/sandstone.k

Question 3

Explain the physical factors which affect drainage basins

Answer 3

1) CLIMATE - high levels of rain = larger river levels / vice versa
2) TYPOGRAOGHY

Question 4

Describe and explain the following features of a storm/flood hydrograph

Answer 4

1) RISING LIMB- steep means rock is impermeable and increases surface run off
Shallow means permeable rock and rapid infiltration and little overland flow

2) PEAK RAINFALL - soil becomes saturated and runs off land leading to potential flood situation
3) LAG TIME- greater drainage density = shorter lag time as water collects quicker
4) PEAK DISCHARGE FLOW - rainfall stopped so no more water can enter river directly
5) DECREASING RIVER LEVEL - evaporation