12 mark questions

assess the role of physical factors in influencing the pattern of future water stress

1. geology - impermeable vs permeable ie himalayas

2. climate variability - natural fluctuations can cause droughts so harder to manage sustainability ie sahel

3. salt water encroachment - salt intrusion ie bangladesh

assess the impacts of climate change on the flows in the hydrological cycle

1. groundwater - reduced recharge so less infiltration, increase droughts ie ogallala

2. soil moisture - increased evaporation so dry and compact ie SSA

3. runoff and through flow - more extreme high and low ie california

assess te extent to which human actions can exacerbate flood risk

1. land use - urbanisation impermeable ie london, deforestation ie amazon

2. can help - locally reduce ie river management like dams, channel straightening

3. river mismanagement - channel straightening, dams ie edenville

4. indirectly via climate changed - enhanced effect, water vapour +FL ie pakistan

assess the ways in which deficits within the hydrological system can have significant impacts

1. agriculture - desertification ie sahel

2. rainforest ecosystems - forest stress and chain reactions ie amazon 2024

3. wetlands - biodiversity hubs ie pantanal

assess the extent to which the hydrological cycle can influence river systems at a local scale

1. hydrological cycle - determines river regime, intense precipitation leads to flooding especially if antecedant ie storm desmond, provides the fuel

2. geology - transfer of water from cycle, determines percolation and so lag time ie himalayas BUT run off determined by precipitation

3. humans - changes speed and volume of run off ie urbanisation london flash floods, deforestation

assess the risks associated with water insecurity

1. industry - needed for the 3, unreliable means poor economy ie india big risk: reputation, gov revenue and employment

2. agriculture - %, disrupted livelihood, crop yields and food security ie ogallala

3. desertification - lack of water for plant growth so soil erosion reducing land fertility ie sahel big risk: humans, economies and environment

assess the effectiveness of hard engineering strategies to manage water supplies

1. water transfers - process ie LHWP better for availability BUT price

2. mega dams - control floods, generate HEP and resevoirs for supplies ie TGD BUT sewage build up

3. desalination - process ie saudi arabia BUT expensive

assess the impacts that climate change may have on hydrological cycle

1. inputs and outputs - precipitation +FL, evaporation with droughts ie sahel

2. stores - permafrost thaws and FL, soil moisture and desertification ie sahel

3. flows - groundwater reduced recharge and with droughts ie ogallala

far reaching effects for human wellbeing ie livelihoods, farming, sanitation

assess the significance of environmental and economic impacts caused by river floods

1. environment (ecosystems, habitats) - ie amazon 2014 sedimentation in rivers, ie pakistan 2022 contamination. significant as extinct species or poisoned aquifers are permanent losses

2. economic activity - ie storm desmond. significant a due to multiplier effect BUT in HICs insurance and govs can mitigate significance

3. infrastructure - edenville dam and pakistan. economy cannot restart BUT more significant for LICs as less financial resilience

environment more significant as permanently alters carbon and water cycles

assess the impact of the global water budget on human water use

budget limits total but humans determine usability

1. budget - most locked up in cryosphere or fossil water. rely on blue water flow but 1% etc. creates water stress in areas where its low ie sahel

2. humans - even if budget high humans reduce effective budget ie ganges river. more significant in LICs creating economic water scarcity

3. climate change - shifting budget from glaciers to oceans causing salt water intrusion ie mekong delta. significant as irreversible

total water budget less significant than spatial distribution and quality

assess the influence of drainage basins physical characteristics on its river regime

1. physical - geology ie impermeable creates flashy regime with high seasonal peaks while permeable creates a stable base flow heavy regime. relief as well

2. land use changes - alter regime set by physical. ie urbanisation means higher peaks and lower troughs. deforestation means more water enters basins ie amazon

3. interaction - physical factors determine land use. urbanisation on low relief and floodplains. afforestation more likely on steep upland areas

assess the role of the cryosphere in maintaining the hydrological cycle

1. seasonal regulation - acts as buffer with accumulation and ablation ie himalayas feed ganges and indus supporting agriculture and HEP for 1bn people

2. LT global storage - global scale cryosphere regulates global water budget with high residence times. static on human timescales but disruption significant with sea level rise and salt water encroachment

3. permafrost - impermeable layer preventing infiltration but thawing means more infiltration and groundwater recharge. regulates drainage and removal changes hydrological cycle

assess the importance of physical factors in determining the shape of a rivers storm hydrograph

1. basin morphology - determines how simultaneously water reaches main channel ie circular basin and density. permanent contraints

2. vegetation - dense forest provides interception and evapotranspiration slowing water BUT humans can change vegetation ie amazon deforestation

3. urbanisation - creates artificial drainage density through gutters and pipes ie london flash floods

link to hydrograph components

assess the significance of different water stores in the global hydrological cycle

1. oceans - 97% all water. primary source for cycle with solar radiation causing evaporation etc. thermal regulator driving thermohaline circ moving heat and moisture. significant as source and regulator

2. cryosphere - 69% fresh water. glaciers and ice caps store water in winter and release in summer. high residence time. significant for LT stability but climate change shifting into ocean store

3. terrestrial groundwater, incl fossil - 30% freshwater. aquifer role. significant for food security ie ogallala supports 30% US livestock. but most fossil water so non renewable and depleting aquifers

4. atmosphere - smallest 0.001% but most active. shortest residence time 9 days and feedback loop so paradoxically most significant store for immediate human life and weather