The water cycle — Paper 2 · A Level Environmental Management (AS only) 8291

1 (a) Fig. 1.1 is a diagram representing some of the flows and stores of the hydrological cycle. vapour transport 40 precipitation 111 precipitation 71 385 evaporation run-off 425 evaporation infiltration lake river ocean groundwater flow values are in hundred thousand km3 Fig. 1.1 (i) State what is meant by the terms run-off and infiltration. run-off … … infiltration … … [2] (ii) Use Fig. 1.1 to explain why more water evaporates from the ocean than returns to the ocean as precipitation. … … … … … … … … [4] (iii) Describe one process, other than evaporation, in which water changes state in the hydrological cycle. … … … … [2] (b) Fig. 1.2 shows changes in past global sea-levels and predicted global sea-levels. The predicted global sea-levels are based upon climate change models produced in 2000. 1.4 1.4 past predicted 1.2 1.2 1.0 1.0 0.8 0.8 change in change in 0.6 0.6 global global sea-level sea-level 0.4 0.4 / m / m 0.2 0.2 0.0 0.0 –0.2 –0.2 –0.4 –0.4 250 500 750 1000 1250 1500 1750 2000 2000 2050 2100 year year Key range of values mean value Fig. 1.2 (i) With reference to Fig. 1.2, describe the changes in global sea-levels in the years before 2000. … … … … [2] (ii) Suggest reasons why data before 1870 has a range of values for the change in global sea-level. … … … … [2] Fig. 1.3 shows the area of Bangladesh that would be affected by a long-term rise in global sea-level. N Rangpur Bogra Sylhet Mymensingh Rajshahi Kushtia Dhaka Comilla Jessore Khulna Chittagong Bay of Bengal Cox’s Bazar Indian Ocean Key 0 40 80 120 160 very densely populated area km densely populated area less densely populated area water other land rivers area inundated by a 1 metre sea-level rise area inundated by a 0.5 metre sea-level rise settlement Fig. 1.3 (iii) Suggest the likely effects of a long-term rise in global sea-level on the environment and people of Bangladesh by the year 2100. Refer to Fig. 1.2 and Fig. 1.3 in your answer. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) run-off: water (from precipitation falling on the land) flows across the land surface (to the oceans); infiltration: water is absorbed into the ground / water moves downwards through the soil spaces / permeable layer; 2 1(a)(ii) example explanations: water vapour rises, cools and condenses into clouds, some clouds are carried over the land, therefore some of this occurs as precipitation over the land; some water from the land returns to ocean as run-off and groundwater flow to evaporate over the ocean; retained in atmosphere / the atmosphere is a water store; use of information from Fig. 1.1, e.g. use of data: 425 (hundred thousand cubic kilometres) evaporate over the ocean, only 385 precipitation over ocean, the difference (425–385 = 40) / 40 is carried over land as water vapour, this falls as precipitation over the land; of the 111 (hundred thousand cubic kilometres) of precipitation over the land, only 71 is from evaporation over the land; the difference of 40 (hundred thousand cubic kilometres) between values for precipitation over land and evaporation over land (111–71 = 40) returns to ocean as groundwater flow and surface run-off; 4 Question Answer Marks 1(a)(iii) One mark for a named process. Two marks for a named process and description of the change in state or transfer from store to store. process: melting / transpiration / freezing / condensation; e.g. melting: water changes from (solid) ice / snow to (liquid) water / e.g. glacier to surface run-off; e.g. transpiration: water changes from (liquid) water to (gas) vapour / water from the soil is transported to the leaves, at the leaf surface the water evaporates and vapour diffuses into the atmosphere from the plant store / vegetation to atmosphere; e.g. freezing: water changes from (liquid) water to (solid) ice / snow / e.g. water to frozen lake; e.g. condensation: water changes from (gas) vapour in the air to (liquid) water in clouds / atmospheric water vapour to precipitation; 2 1(b)(i) overall pattern shows increases and decreases; use of data from graph to support, e.g. the range from the highest in approx. 1200 to lowest sea-level in 1750 is 0.48 m; reference to oscillations within the overall pattern; 2 1(b)(ii) sea-levels before 1870 are based upon estimates using qualitative evidence / different models / different people (making estimates); from e.g. geological observations / ice core analysis; (quantitative) data was not recorded / less likely to be recorded; technology / equipment is now more accurate / technology is now more available / recorded now using, e.g. instrumental records / tide gauges / satellites; 2 Question Answer Marks 1(b)(iii) Use of data from Fig. 1.2 and Fig. 1.3 as well as reference to both people and the environment required for full marks. Max. six marks if no reference to either figure. An effect can be developed for an additional mark. Examples may include: environment, e.g.: inundation of land by sea water; low-lying land will be permanently flooded; salinisation of soil; salinisation of freshwater aquifers; increasing salinity of river water; effect on freshwater ecosystems; erosion; people, e.g.: reduction in land area available for population / displacement of settlements / re-location of settlements; reduction in land area available for agriculture / crops; effect on freshwater supply for domestic consumption; effect on freshwater supply for irrigation / crop productivity; effect on freshwater fisheries; effect on wetlands / wetland flooding; use of Fig. 1.3, e.g.: estimation of (approximately 10%) of land will be permanently flooded if the sea-level rise is 0.5 m; proximity to already densely populated region; estimation of (approximately 15%) of land will be permanently flooded if the sea-level rise is 1 m; includes an area that is already densely populated and close in proximity to areas very densely populated, e.g. Dhaka, Khulna; 8 Question Answer Marks 1(b)(iii) use of Fig. 1.2, e.g. ref. to range i.e. estimated sea-level rise could be more or less than 0.5 / 1 metre(s) based on the range of outcomes and have a greater or lesser effect on the area of Bangladesh; these are only models and outcome may be different to this prediction; possibility that sea-level rise is as much as 1.4 metres; Accept other valid effects.

This question in 8291/21 May/June 2017

2 (a) Fig. 2.1 shows part of a water cycle in a tropical rainforest. rainfall evapotranspiration transpiration evaporation interception stem flow direct throughfall leaf drip infiltration throughflow run-off Fig. 2.1 (i) State what is meant by the following terms: evaporation … … interception … … run-off. … … [3] (ii) With reference to Fig. 2.1, describe how a balance between inputs and outputs of water can be maintained in a tropical rainforest. … … … … … … … … … … … … [6] (b) Fig. 2.2 shows a section of a slope containing undisturbed forest on the left and the same slope after deforestation on the right. undisturbed forest after deforestation soil + roots trees water tableKey evaporation and transpiration table water rainfall run-off infiltration saturated rock river soil / sediment Fig. 2.2 (i) Using Fig. 2.2, describe the effect of deforestation on the local water cycle. … … … … … … … … … … … … [6] (ii) Suggest methods that can be used to reduce the impact of deforestation on the local environment. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 2(a)(i) evaporation: formation of water vapour / gas from liquid water; interception: capture of rainfall as it falls / rainfall is prevented from reaching the ground directly; run-off: water moving over soil / land surface; 3 Question Answer Marks 2(a)(ii) Award one mark for a list of correct inputs and outputs. Award development of either inputs or outputs to a max. of three marks each. Award a max. of four marks if there is no balance, e.g. only input. Award one mark for a summative statement of identified input(s) equal to identified output(s). inputs: rainfall, precipitation, throughflow AND outputs: throughflow, run-off, evapotranspiration; (Accept evaporation or transpiration.) description of inputs in rainforest: some rain as it falls is collected / stored by the leaves of the tropical rainforest canopy; (interception) water runs down plant stems / tree trunks to the soil surface; (stem flow) water from leaves drops / reaches the ground; (leaf drip) and water moves into the soil store; (infiltration) water is absorbed by the roots / taken up by vegetation / moves through the plant via the transpiration stream, some is used by the plant in photosynthesis / primary productivity and stored in plant biomass; water moves into the area by groundwater flow from groundwater stores outside of the area; (Credit use as an output to other areas.) description of outputs in rainforest: water in the soil can move downwards, percolation to groundwater stores and groundwater flow; (run-off) transport to rivers / river discharge; water loss from vegetation / soil surfaces (evaporation); roots of plants take up water from the ground, from leaves into the atmosphere (transpiration); water vapour condenses into clouds / to the atmospheric water store; 6 Question Answer Marks 2(b)(i) less water in vegetation store; with less vegetation there is a reduction in interception; increased impact of rainfall on the soil surface; soil compaction; reduced infiltration; less water in the soil water store; less percolation to groundwater; lowering of the water table; increase in surface run-off; increase in soil erosion; increased siltation / sediment accumulation in river channel; increased risk of flooding during period of rain; reduction in evapotranspiration; credit ref. to local microclimate, e.g. less cloud / less humidity / less rainfall / less atmospheric water; possible desertification; Credit references to the deforested slope compared to undisturbed forest in Fig. 2.2. 6 Question Answer Marks 2(b)(ii) Award one mark for each method. Allow up to two further marks per method for development and exemplification. forest conservation; e.g. protected areas / national park; to reduce habitat loss / prevent loss of biodiversity; afforestation; re-populating the area with more trees to increase roots in soil; to reduce exposed soil area; resource managed areas; e.g. selective logging; to maintain tree cover; natural succession; eliminating grazing animals; ecosystem restoration; sustainable land use / changing agricultural practices; agroforestry / combining agricultural and forestry technologies; combining trees and shrubs with crops and / or livestock; intercropping / two or more plant species; increase ground cover; using mulch; contour ploughing; terracing; planting buffer strips adjacent to river; 5 Section B

This question in 8291/22 May/June 2017

2 (a) Fig. 2.1 shows part of a water cycle in a tropical rainforest. rainfall evapotranspiration transpiration evaporation interception stem flow direct throughfall leaf drip infiltration throughflow run-off Fig. 2.1 (i) State what is meant by the following terms: evaporation … … interception … … run-off. … … [3] (ii) With reference to Fig. 2.1, describe how a balance between inputs and outputs of water can be maintained in a tropical rainforest. … … … … … … … … … … … … [6] (b) Fig. 2.2 shows a section of a slope containing undisturbed forest on the left and the same slope after deforestation on the right. undisturbed forest after deforestation soil + roots trees water tableKey evaporation and transpiration table water rainfall run-off infiltration saturated rock river soil / sediment Fig. 2.2 (i) Using Fig. 2.2, describe the effect of deforestation on the local water cycle. … … … … … … … … … … … … [6] (ii) Suggest methods that can be used to reduce the impact of deforestation on the local environment. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 2(a)(i) evaporation: formation of water vapour / gas from liquid water; interception: capture of rainfall as it falls / rainfall is prevented from reaching the ground directly; run-off: water moving over soil / land surface; 3 Question Answer Marks 2(a)(ii) Award one mark for a list of correct inputs and outputs. Award development of either inputs or outputs to a max. of three marks each. Award a max. of four marks if there is no balance, e.g. only input. Award one mark for a summative statement of identified input(s) equal to identified output(s). inputs: rainfall, precipitation, throughflow AND outputs: throughflow, run-off, evapotranspiration; (Accept evaporation or transpiration.) description of inputs in rainforest: some rain as it falls is collected / stored by the leaves of the tropical rainforest canopy; (interception) water runs down plant stems / tree trunks to the soil surface; (stem flow) water from leaves drops / reaches the ground; (leaf drip) and water moves into the soil store; (infiltration) water is absorbed by the roots / taken up by vegetation / moves through the plant via the transpiration stream, some is used by the plant in photosynthesis / primary productivity and stored in plant biomass; water moves into the area by groundwater flow from groundwater stores outside of the area; (Credit use as an output to other areas.) description of outputs in rainforest: water in the soil can move downwards, percolation to groundwater stores and groundwater flow; (run-off) transport to rivers / river discharge; water loss from vegetation / soil surfaces (evaporation); roots of plants take up water from the ground, from leaves into the atmosphere (transpiration); water vapour condenses into clouds / to the atmospheric water store; 6 Question Answer Marks 2(b)(i) less water in vegetation store; with less vegetation there is a reduction in interception; increased impact of rainfall on the soil surface; soil compaction; reduced infiltration; less water in the soil water store; less percolation to groundwater; lowering of the water table; increase in surface run-off; increase in soil erosion; increased siltation / sediment accumulation in river channel; increased risk of flooding during period of rain; reduction in evapotranspiration; credit ref. to local microclimate, e.g. less cloud / less humidity / less rainfall / less atmospheric water; possible desertification; Credit references to the deforested slope compared to undisturbed forest in Fig. 2.2. 6 Question Answer Marks 2(b)(ii) Award one mark for each method. Allow up to two further marks per method for development and exemplification. forest conservation; e.g. protected areas / national park; to reduce habitat loss / prevent loss of biodiversity; afforestation; re-populating the area with more trees to increase roots in soil; to reduce exposed soil area; resource managed areas; e.g. selective logging; to maintain tree cover; natural succession; eliminating grazing animals; ecosystem restoration; sustainable land use / changing agricultural practices; agroforestry / combining agricultural and forestry technologies; combining trees and shrubs with crops and / or livestock; intercropping / two or more plant species; increase ground cover; using mulch; contour ploughing; terracing; planting buffer strips adjacent to river; 5 Section B

This question in 8291/23 May/June 2017

1 (a) Fig. 1.1 gives information on some effects of increasing urban development on a local water cycle. increasing urban development % of land covered by 0 25 75 100 impervious surfaces (an impervious surface does not allow water to infiltrate) precipitation 100 100 100 100 / arbitrary units evaporation 40 38 35 30 (includes evapotranspiration) / arbitrary units infiltration 50 42 35 15 / arbitrary units run-off 10 20 30 55 /arbitrary units Fig. 1.1 (i) With reference to Fig. 1.1, describe the trend between increasing urban development and both evaporation and infiltration in this local water cycle. evaporation … … … … infiltration … … … … [4] (ii) Using the data in Fig. 1.1, calculate the percentage increase in run-off from 0% land covered by impervious surfaces to 100% land covered by impervious surfaces. Show your working. … % [2] (iii) Explain why an increase in the percentage of land covered by impervious surfaces increases run-off. … … … … [2] (iv) Briefly explain two effects of run-off from urban areas on a river environment. … … … … … … … … [4] (b) Fig. 1.2 shows a vegetation zoning system designed to reduce the impact of human activity on a river environment. run-offrun-offfrofromm agriculturalagricultural lalanndd run-orun-o ffff fromfrom ururbabann lalandnd river zone 3 zone 2 zone 1 zone 1 zone 2 zone 3 grass managed natural natural managed grass forest forest forest forest benefits wildlife habitat protection flood reduction nutrient uptake by vegetation run-off reduction river bank stability Fig. 1.2 Describe and explain how the vegetation zoning system shown in Fig. 1.2 reduces the negative impact of human activity on the river environment. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) Trend: with increasing urban development / more buildings and less vegetation or soil cover, there is a decreasing evaporation; with (increasing urban development) there is decreasing infiltration; use of data/information from Fig.1.1to support trend: there is an overall decrease from, 40 to 30 / 10 arbitrary units of evaporation and 50 to15 arbitrary / 35 units of infiltration; further manipulation of data e.g. a non-linear rate of decrease is described / e.g. increasing impervious surfaces by 25% decreases evaporation by 2 units (5%) but increasing impervious surfaces by 100% decreases evaporation by 10 units (25%), 5 × more; 4 Do not accept any references to differences in rainfall in questions 1(a)(i)–(iv). Accept alternative descriptions using data and information. 1(a)(ii) 55 – 10 / 10 = 45 / 10 = 4.5; 4.5 × 100 = 450% 2 Award 2 marks for a correct answer without working. 450% = 2 marks ecf for incorrect difference from (i). 1(a)(iii) impermeable / non-porous surfaces; prevent water from being absorbed / prevent infiltration into the ground; more water will flow overland as run-off; there is less resistance to run-off (due to less vegetation / soil) increasing the rate of flow of water overland; reference to structure of the impervious surfaces e.g. gullies which collect and channel the flow of water across the surface of the land to drains; 2 Question Answer Marks Guidance 1(a)(iv) run-off contains pollutants which contaminate the river environment; e.g. oil from vehicles collects on the water surface; reducing light penetration; decreasing photosynthesis by aquatic plants; nutrients from garden fertilisers, increases the concentration of nutrients in the river water / eutrophication; lowers biodiversity; organic matter in sewage increases biochemical oxygen demand; depletion of oxygen in water; detergents / chemicals; alter the pH of the water; run-off carries sediment / debris; increasing turbidity; run-off increases river discharge; increasing the chance of river flooding; damaging / eroding waterside vegetation / river banks; 4 Award 1 mark for a general point on effect of pollution. Or For each of 2 effects 2 × 2. (1 mark for an explanation of 1 effect and 1 mark for further exemplification.) Pollution must refer to be river pollution. Do not accept pollutants which are not carried in run-off. Do not accept fertiliser alone – must be linked to an urban area. Do not accept increased run-off alone as in previous question. Question Answer Marks Guidance 1(b) zone 1 / natural forest is linked to the stabilising of river bank by: tree roots holding soil particles; reducing the risk of riverbank erosion; zones 1 and 2 / natural and managed forest is linked to reducing the likelihood of river flooding through: forest soil absorbing water; reducing river discharge; trapping sediment / soil from agricultural land; reducing sedimentation; zone 2 / managed forest has fast-growing plants which increase nutrient uptake; zones 1–3 / natural forest, managed forest, grass increase nutrient uptake: vegetation absorbs excess nutrients; reducing the input of nutrients into the river / reducing the risk of eutrophication; zones 1–3 / natural forest, managed forest, grass slows the rate of run-off : by providing ground cover; increasing infiltration; improving drainage; zones 1–3 / natural forest, managed forest, grass increases biodiversity by: providing ecological benefits for wildlife; nesting / breeding sites; stratification / variety of habitats / niche; other benefits not listed in Fig. 1.2: e.g. filters groundwater flow from non-point source pollution; acts as a buffer strip; 8 Max 5 if zoning system discussed as a whole and no analysis of zones.

This question in 8291/21 Oct/Nov 2017

2 (a) Fig. 2.1 shows a diagram of a local water cycle. precipitation evaporation from vegetationinfiltration evaporation A B water table riverriver groundwater flow groundwater flow (not to scale) Key A proposed urban development B agricultural activity Fig. 2.1 (i) With reference to Fig. 2.1, state one input and one output of the local water cycle. input … output … [1] (ii) Use Fig. 2.1 to explain why the level of the water table may rise and fall. … … … … … … [3] (iii) Explain how proposed urban development in the area labelled A in Fig. 2.1 could increase the chance of flooding. … … … … … … … … [4] (iv) Explain how agricultural activity in the area labelled B in Fig. 2.1 could cause the river to become polluted. … … … … … … … … [4] (b) Fig. 2.2 shows effects of a single event of organic pollution on a river. river concentration distance Key input of organic pollution organic pollution river flow organic matter mineral ions (e.g. nitrates and phosphates) dissolved oxygen Fig. 2.2 With reference to Fig. 2.2, describe and explain the changes in the quality of river water with increasing distance from the input of organic pollution. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 2(a)(i) input: precipitation / river / groundwater flow; output: evaporation / evapotranspiration / river / groundwater flow; 1 Both correct for one mark. Accept evapotranspiration for evaporation from vegetation. 2(a)(ii) water table can rise – an explanation linking: increased rainfall; increased infiltration; pores in underground, porous store fill with water / saturated; water table can fall – an explanation linking: increased temperature; increased uptake of water from soil by vegetation; increased evaporation (from vegetation) / evapotranspiration; reduced precipitation; less infiltration; decrease in saturated zone; increase in extraction of water for human use; 3 Credit reverse arguments only once i.e. increased / deceased precipitation / rainfall. 2(a)(iii) reduced soil / vegetation cover; increase in impermeable surfaces; less infiltration; increased surface run-off; increase in poor quality runoff-from land surface; water collected from drains; increased discharge to streams / river; 4 Award up to 4 marks for single points or award 2 × 2 marks for 2 developed points. Question Answer Marks Guidance 2(a)(iv) less permanent vegetation cover; soil surface exposed for long periods between crops; increased loss of nutrients from soil; increased leaching; increased nutrient in surface run-off; increased nutrient in groundwater flow due to infiltration and percolation through permeable layers into the groundwater; increased use of fertilisers on land; irrigation water; enhanced nutrient load; eutrophication; 4 Accept alternative agricultural effects e.g. grazing animals. Award up to 4 marks for single points or award 2 × 2 marks for 2 developed points. Question Answer Marks Guidance 2(b) description of water quality: a decrease in water quality immediately following the discharge of organic pollution; as shown by the initial increase in density of organic pollution / increase in organic matter; decrease in dissolved oxygen; followed by a gradual improvement in water quality downstream; decreasing organic pollution with distance downstream / gradual decease in organic matter; gradual increase in oxygen levels; explanation: sewage effluent / discharge; contains suspended solids / organic matter; increases turbidity; oxygen levels decrease due to decomposition; by decomposer organisms / e.g.; use oxygen in respiration; increased BOD; decreasing organic matter levels are due to the breakdown of organic matter; dispersion / dilution; increased oxygenation of water; due to aeration of water; decreasing microbial activity; the gradual increase in concentration of mineral ions can be linked to the release of minerals from the decomposition of organic material; 8 Award notionally 4 marks for description and 4 for explanation.

This question in 8291/22 Oct/Nov 2017

1 (a) Table 1.1 shows the approximate residence time for some major water stores. Residence time is the time water spends in a particular water store. Table 1.1 water store approximate residence time glaciers 10 to 10 000 years deep groundwater 10 000 years shallow groundwater 100 to 200 years lakes 10 to 100 years living organisms 1 week oceans 4000 years rivers 2 weeks to 6 months soil moisture 2 weeks to 1 year (i) State the water store with the lowest approximate residence time in Table 1.1. … [1] (ii) With reference to Table 1.1, suggest why the residence times given in Table 1.1 are approximate. … … … … [2] (b) Fig. 1.1 is a newspaper extract about an incident of river pollution in Brazil. November 2015 River and sea threatened by industrial sludge Dams holding 50 million cubic metres of iron-mine waste collapsed and discharged a flood of thick, red, toxic sludge. The sludge covered a small town and made its way into the River Doce. A 650 km stretch of the river was affected. The sludge greatly increased the concentration of suspended particles in the water and drastically reduced the oxygen levels. People living in the area are now dependent on supplies of bottled water. Two weeks later the water in the estuary (where the river joins the sea) turned brown. The pollution then spread out along the coast, affecting a nature reserve containing nesting sites of the endangered leatherback turtle. Fig. 1.1 (i) State the source of the river pollution referred to in Fig. 1.1. … … [1] (ii) With reference to Fig. 1.1, describe how the river became polluted. … … [1] (iii) Suggest the effects of the pollution on the quality of the river water. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (iv) Fig. 1.2 shows the distribution of the pollution where the River Doce flows into the sea. River Doce pollution sea Fig. 1.2 Explain the distribution of the pollution in the sea shown in Fig. 1.2. … … … … [2] (v) Describe the possible effects of industrial pollution on coastal and marine environments. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (c) Briefly describe strategies that can be used to manage river pollution. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 1(a)(i) living organisms; 1 1(a)(ii) there is a wide variation in the residence time for water stores of each type; water stores have different volumes / locations / size; rates of input / output vary; different factors can change over time; e.g. rivers will vary in size, each river will have a different value, and so (a range of values); 2 1(b)(i) mining waste / industrial waste / toxic metals; 1 1(b)(ii) dam burst, waste sludge released, flowed into the river; 1 1(b)(iii) increased turbidity / an increased concentration of suspended particles; reduced light penetration / less light for plants in water; reduced photosynthesis / death of plants; reduced oxygen levels; less respiration; death of animals / organisms in water; reduced biodiversity; increased concentration of metals in water; water contamination; reduced quality of water as drinking water for human consumption / agricultural use / water supply for livestock; 4 1(b)(iv) where the river flows into estuary, a concentrated area is visible, extending over a wide area with decreasing intensity; due the sea currents / tide; extending both out to sea and along the shoreline; disperses / dilution / mixing of the pollution with a large volume of sea water; 2 Question Answer Marks 1(b)(v) death of aquatic organisms; reduced food supply for both aquatic and land based organisms; effect on food chains / web; effect on population size of species; reduced biodiversity; bioaccumulation; degradation of the marine environment; detrimental to the aesthetics of the coastal environment; negative economic effects / fishing industry / human food supply / effect on tourism; Fig.1.1: describes an effect linked to the nature reserve; reduces breeding / nesting sites of the endangered leatherback turtle; 4 1(c) management of leakage, seepage, run-off from industrial sites; eliminating or reducing pollution at source; reducing waste discharge; recycling of waste water to reduce input into river; enforced legislation controlling the discharge of industrial waste; monitoring of rivers by suitable organisations to identify changes in water quality; risk assessment; clean-up operations; management of any form of river pollution not just industrial: reducing agricultural run-off through appropriate management; management of domestic waste by water treatment and waste treatment. 5

This question in 8291/22 May/June 2018

1 (a) Table 1.1 shows the approximate residence time for some major water stores. Residence time is the time water spends in a particular water store. Table 1.1 water store approximate residence time glaciers 10 to 10 000 years deep groundwater 10 000 years shallow groundwater 100 to 200 years lakes 10 to 100 years living organisms 1 week oceans 4000 years rivers 2 weeks to 6 months soil moisture 2 weeks to 1 year (i) State the water store with the lowest approximate residence time in Table 1.1. … [1] (ii) With reference to Table 1.1, suggest why the residence times given in Table 1.1 are approximate. … … … … [2] (b) Fig. 1.1 is a newspaper extract about an incident of river pollution in Brazil. November 2015 River and sea threatened by industrial sludge Dams holding 50 million cubic metres of iron-mine waste collapsed and discharged a flood of thick, red, toxic sludge. The sludge covered a small town and made its way into the River Doce. A 650 km stretch of the river was affected. The sludge greatly increased the concentration of suspended particles in the water and drastically reduced the oxygen levels. People living in the area are now dependent on supplies of bottled water. Two weeks later the water in the estuary (where the river joins the sea) turned brown. The pollution then spread out along the coast, affecting a nature reserve containing nesting sites of the endangered leatherback turtle. Fig. 1.1 (i) State the source of the river pollution referred to in Fig. 1.1. … … [1] (ii) With reference to Fig. 1.1, describe how the river became polluted. … … [1] (iii) Suggest the effects of the pollution on the quality of the river water. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (iv) Fig. 1.2 shows the distribution of the pollution where the River Doce flows into the sea. River Doce pollution sea Fig. 1.2 Explain the distribution of the pollution in the sea shown in Fig. 1.2. … … … … [2] (v) Describe the possible effects of industrial pollution on coastal and marine environments. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (c) Briefly describe strategies that can be used to manage river pollution. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 1(a)(i) living organisms; 1 1(a)(ii) there is a wide variation in the residence time for water stores of each type; water stores have different volumes / locations / size; rates of input / output vary; different factors can change over time; e.g. rivers will vary in size, each river will have a different value, and so (a range of values); 2 1(b)(i) mining waste / industrial waste / toxic metals; 1 1(b)(ii) dam burst, waste sludge released, flowed into the river; 1 1(b)(iii) increased turbidity / an increased concentration of suspended particles; reduced light penetration / less light for plants in water; reduced photosynthesis / death of plants; reduced oxygen levels; less respiration; death of animals / organisms in water; reduced biodiversity; increased concentration of metals in water; water contamination; reduced quality of water as drinking water for human consumption / agricultural use / water supply for livestock; 4 1(b)(iv) where the river flows into estuary, a concentrated area is visible, extending over a wide area with decreasing intensity; due the sea currents / tide; extending both out to sea and along the shoreline; disperses / dilution / mixing of the pollution with a large volume of sea water; 2 Question Answer Marks 1(b)(v) death of aquatic organisms; reduced food supply for both aquatic and land based organisms; effect on food chains / web; effect on population size of species; reduced biodiversity; bioaccumulation; degradation of the marine environment; detrimental to the aesthetics of the coastal environment; negative economic effects / fishing industry / human food supply / effect on tourism; Fig.1.1: describes an effect linked to the nature reserve; reduces breeding / nesting sites of the endangered leatherback turtle; 4 1(c) management of leakage, seepage, run-off from industrial sites; eliminating or reducing pollution at source; reducing waste discharge; recycling of waste water to reduce input into river; enforced legislation controlling the discharge of industrial waste; monitoring of rivers by suitable organisations to identify changes in water quality; risk assessment; clean-up operations; management of any form of river pollution not just industrial: reducing agricultural run-off through appropriate management; management of domestic waste by water treatment and waste treatment. 5

This question in 8291/23 May/June 2018

1 (a) Fig. 1.1 shows part of a local hydrological cycle before and after urban development. X runoff precipitation Diagram A: infiltration before urban development interception X runoff precipitation Diagram B: infiltration after urban development interception Key = movement of water width of arrow = relative volume of water Fig. 1.1 (i) Name the process labelled X in Fig. 1.1. … [1] (ii) Describe two changes in the movement of water after urban development shown in Fig. 1.1. … … … … [2] (iii) Explain how urban development may cause rivers to flood. … … … … … … … … [4] (b) Fig. 1.2 shows the severity of drought in areas of the USA for two different years. January 12, 2010 N January 10, 2017 Key abnormally dry moderate drought severe drought extreme drought exceptional drought Fig. 1.2 (i) State three differences in the drought conditions in the USA between 2010 and 2017 shown in Fig. 1.2. … … … … … … [3] (ii) Explain how changes in the hydrological cycle can lead to the development of drought conditions. … … … … … … … … [4] (iii) Describe strategies to manage the sustainable supply of water for domestic, industrial and agricultural use. … … … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 1(a)(i) (evapo)transpiration 1 1(a)(ii) increased surface run-off; reduced (evapo)transpiration; reduced interception; reduced infiltration; max 2 1(a)(iii) increased building / infrastructure (using non-porous materials); reduces absorption / increases surface run-off; loss of trees; reduces evapotranspiration; less roots to slow the movement of water; greater volume of water enters rivers; more rapidly; increased amount raises river level too rapidly; max 4 1(b)(i) January 10th, 2017: there are more areas experiencing drought conditions; the drought areas are more widespread across the states; drought conditions are moving eastwards; drought conditions have spread south; there are more areas with the most extreme droughts; the area with the most extreme drought in 2010 is no longer experiencing that; max 3 1(b)(ii) patterns in local climate change; precipitation decreases; storm tracks change; increased temperatures; increase evaporation; max 4 Question Answer Marks 1(b)(iii) uses of natural supplies and new technologies; storing runoff in reservoirs; diverting flows from water-abundant to water-scarce regions; extracting aquifer resources; water reuse / use of grey water; desalination; rainwater harvesting; reducing high losses / waste from water supply distribution systems / households; education; max 6

This question in 8291/22 May/June 2019

1 (a) Fig. 1.1 shows part of a local hydrological cycle before and after urban development. X runoff precipitation Diagram A: infiltration before urban development interception X runoff precipitation Diagram B: infiltration after urban development interception Key = movement of water width of arrow = relative volume of water Fig. 1.1 (i) Name the process labelled X in Fig. 1.1. … [1] (ii) Describe two changes in the movement of water after urban development shown in Fig. 1.1. … … … … [2] (iii) Explain how urban development may cause rivers to flood. … … … … … … … … [4] (b) Fig. 1.2 shows the severity of drought in areas of the USA for two different years. January 12, 2010 N January 10, 2017 Key abnormally dry moderate drought severe drought extreme drought exceptional drought Fig. 1.2 (i) State three differences in the drought conditions in the USA between 2010 and 2017 shown in Fig. 1.2. … … … … … … [3] (ii) Explain how changes in the hydrological cycle can lead to the development of drought conditions. … … … … … … … … [4] (iii) Describe strategies to manage the sustainable supply of water for domestic, industrial and agricultural use. … … … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 1(a)(i) (evapo)transpiration 1 1(a)(ii) increased surface run-off; reduced (evapo)transpiration; reduced interception; reduced infiltration; max 2 1(a)(iii) increased building / infrastructure (using non-porous materials); reduces absorption / increases surface run-off; loss of trees; reduces evapotranspiration; less roots to slow the movement of water; greater volume of water enters rivers; more rapidly; increased amount raises river level too rapidly; max 4 1(b)(i) January 10th, 2017: there are more areas experiencing drought conditions; the drought areas are more widespread across the states; drought conditions are moving eastwards; drought conditions have spread south; there are more areas with the most extreme droughts; the area with the most extreme drought in 2010 is no longer experiencing that; max 3 1(b)(ii) patterns in local climate change; precipitation decreases; storm tracks change; increased temperatures; increase evaporation; max 4 Question Answer Marks 1(b)(iii) uses of natural supplies and new technologies; storing runoff in reservoirs; diverting flows from water-abundant to water-scarce regions; extracting aquifer resources; water reuse / use of grey water; desalination; rainwater harvesting; reducing high losses / waste from water supply distribution systems / households; education; max 6

This question in 8291/23 May/June 2019

2 (a) Fig. 2.1 shows the flows and stores of water in the global hydrological cycle. A number is given to indicate the amount of water within each flow or store. atmosphere 12.7 ocean to land water vapour transport 40 ocean ocean land evapotrans- precipitation evaporation precipitation piration 373 413 113 73 ocean 1 335 040 rivers, lakes riverriver flowflow ice glaciers 26 350 178 3838 infiltration soil moisture 122 percolation ground water flow 2 ground water 15 300 permafrost 22 Key direction of flow store / arbitrary units Fig. 2.1 (i) State where most of the water that has evaporated from the oceans falls as precipitation shown in Fig. 2.1. … [1] (ii) Calculate the total amount of stored water in Fig. 2.1. … arbitrary units [2] (iii) The global hydrological cycle is a closed system. Explain reasons why a local hydrological cycle, such as in a drainage basin, can not be described as a closed system. … … … … … … … … [4] (iv) Describe two ways in which human activities can affect a local hydrological cycle. … … … … … … … … [4] (b) Fig. 2.2 is a map showing the predicted loss of land to the sea as a result of a rise in sea levels of 3 metres in Florida, United States of America. N Atlantic Ocean DaytonaDaytona BeachBeach StSt PetersburgPetersburg WestWest PalmPalm BeachBeach Key Gulf predicted land of MiamiMiami lost to the sea Mexico BeachBeach land predicted to remain above water water Fig. 2.2 (i) Suggest causes for the predicted rise in sea levels shown in Fig. 2.2. … … … … … … … … [4] (ii) Describe strategies that could be used to manage the effects of coastal inundation caused by a rise in sea level of 3 metres, such as that shown in Fig. 2.2. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 2(a)(i) ocean; 1 2(a)(ii) 1 377 024.7(arbitrary units); correct working ; 2 2(a)(iii) closed system does not lose water; local hydrological cycle loses / gains water; run-off into rivers; flows away from the region; groundwater can flow into rivers; water evaporates and can be blown away by winds; animals can migrate away from the region; effects of storms / climate change; max 4 4 2(a)(iv) increased carbon emissions; lead to climate change; weather patterns change; agricultural practices change evapotranspiration rates; drainage of land; increased urbanisation increases run-off; increased industrial / domestic use / overuse of boreholes and aquifers reduces stores; building of dams for reservoirs / HEP; leads to increased evaporation; max 4 4 2(b)(i) Increased carbon dioxide / methane emissions; lead to global warming / climate change; because heat is trapped / reflected back to Earth; increased melting of arctic ice / glaciers; increases volume of water in oceans / seas; max 4 4 Question Answer Marks 2(b)(ii) reduce emissions of carbon dioxide / methane; example e.g. factory scrubbers / catalytic converters / electric cars; move away from fossil fuels; increase reliance on renewable energy forms; named example; traffic management schemes / car pool / public transport; improve coastal defences; prepare / educate population; build levees / dykes; treat increased salinity of coastal soils to sustain agriculture; max 5 5

This question in 8291/22 Oct/Nov 2019

1 (a) Fig. 1.1 shows the various stores of water found in the hydrosphere. freshwater lakes groundwater inland sea 0.009% 0.008% salt water 97.2% 2.8% 0.02% rivers 0.001% soil water ice sheets and glaciers atmosphere 0.005% 2.15% 0.001% Fig. 1.1 (i) Fig. 1.1 shows that 97.2% of water in the hydrosphere is salt water. State the type of water that makes up the remaining 2.8%. … [1] (ii) Calculate the percentage of water found as groundwater in the hydrosphere. … % [1] (iii) Describe two environmental problems which might be caused by the melting of ice sheets and glaciers. … … … … … … … … [4] (b) Aquifers are underground stores of groundwater. The three types of aquifer are confined, unconfined and perched. (i) Complete Table 1.1 by matching the type of aquifer to the correct description. confined unconfined perched Table 1.1 description type of aquifer an aquifer which is found above the water table where an impermeable layer of rock or material lies above the regional water table an aquifer where the water from the ground above is prevented from seeping in by a layer of impermeable rock or material lying above the aquifer an aquifer where water from the ground directly above can seep into the aquifer [2] (ii) State two causes of groundwater depletion from aquifers. … … … [2] (iii) Explain two strategies to conserve groundwater in aquifers. … … … … … … … … [4] (c) As the population of an area increases, the demands for water change from those of a rural area to those of an urban area. Describe and explain the changes in demand for water as an area becomes more urbanised. … … … … … … … … … … [5] (d) The creation of an artificial reservoir can provide access to water for many people. Suggest one disadvantage of the creation of an artificial reservoir. … … [1] [Total: 20]

20 marks

Mark scheme: 1(a)(i) fresh (water) 1 1(a)(ii) 0.63 (%); 1 1(a)(iii) increased flow of water into streams and rivers; leads to increased flooding; increased flow into seas from rivers; raises sea-level; increases risk of coastal flooding; damage to communities; loss of coastal areas / erosion; loss of land / damage to infrastructure; increased risk of salinisation of coastal soils; loss of land for agriculture; loss of annual melt waters; affects some agricultural practices; affects soil fertility; max 4 4 Question Answer Marks 1(b)(i) description type of aquifer an aquifer which is found above the water table where an impermeable layer of rock or material lies above the regional water table perched an aquifer where the water from the ground above is prevented from seeping in by a layer of impermeable rock or material lying above the aquifer confined an aquifer where water from the ground directly above can seep into the aquifer unconfined one correct; all three correct; 2 1(b)(ii) over-use / demand; for domestic / industrial / agricultural use; lack of rainfall / drought conditions; due to climate change / natural cycles; over-pumping could lead to salt intrusion in coastal aquifers reducing availability of freshwater; max 2 2 Question Answer Marks 1(b)(iii) education; to reduce demand for water; to encourage less wastage; legislation; to limit amounts that can be pumped for industrial / agricultural use; public attitudes; campaigns for reducing water use and waste; named example, e.g. not washing cars; use of grey water; to irrigate plants and gardens; to recycle / re-use water; max 4 4 Question Answer Marks 1(c) population increases; so greater demand for water; change from agricultural use to domestic use; as size of residential areas increases; increase in use for non-essential purposes; described, e.g. watering gardens / cleaning cars; increase in waste of water; larger population more likely to waste water than smaller rural population; max 5 5 1(d) destruction of habitats; noise during construction; displacement of people / loss of traditional jobs; disruption of river flow / annual flooding affected; silting downstream of the dam; max 1 1

This question in 8291/22 Oct/Nov 2020

1 (a) Fig. 1.1 shows information about water needed to produce cotton for clothing. Content removed due to copyright restrictions. Fig. 1.1 (i) Calculate the volume of water in litres used to make jeans for a class of 30 students. … litres [1] (ii) A volume of 75 000 litres of water is used to produce t-shirts for a class of students. Calculate the number of people for which this volume would provide drinking water for one year. … [2] (iii) Describe the impact of growing cotton on water stores and flows. Use information from Fig. 1.1 to support your answer. … … … … … … … … [4] (b) Fig. 1.2 shows the level of water stress in the top ten cotton producing countries. Water stress is when the demand for water exceeds supply. very high water high stress medium moderate low (#1) (#2) (#3) (#4) (#5) (#6) (#7) (#8) (#9) (#10) Greece India China USAPakistan BrazilUzbekistanAustralia TurkeyArgentina cotton producing countries in decreasing order Fig. 1.2 (i) Discuss what is shown by the data in Fig. 1.2. … … … … [3] (ii) Water use for China in 2019 was 598.1 billion m3. The total renewable water resources available in 2019 were 2840 billion m3. Calculate the water stress for China in 2019. Use the formula: water stress = (water use ÷ total renewable water resources available) × 100 … % [1] (c) Fig. 1.3 shows the reduction in size of the Aral Sea located in Uzbekistan and Kazakhstan. 1960 1971 1976 X X X 1989 2014 2020 X X X Key water seasonal lakes land Fig. 1.3 (i) Estimate the percentage loss in area for the Aral Sea between 1960 and 1989 shown in Fig. 1.3. … % [1] (ii) Suggest the impact of the loss of the Aral Sea on people living at location X shown in Fig. 1.3. … … … … [2] (iii) A new dam project is planned to divert water to help increase water levels in the Aral Sea. Suggest reasons why people may object to the construction of a dam. … … … … … … [3] (d) Growing cotton uses more pesticides than any other crop. Suggest the negative impacts of pesticide use. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) 240 000; 1 1(a)(ii) 75; 2500 / 2.5 = 1000; 75 000 / 1000; 2 1(a)(iii) large scale use of water; reduction in ground water stores; diversion of natural water flows; (groundwater depletion) leads to salt water intrusion / salinisation; land subsidence; 4 1(b)(i) most cotton producing countries have some water stress; no pattern to ranking and stress level; Uzbekistan has extremely high water stress; Brazil has the lowest water stress; cotton production is not the main cause of water stress ; 3 1(b)(ii) 21.059 / 21.06 / 21.1; 1 1(c)(i) any number between 20 and 35%; 1 1(c)(ii) loss of fishing industry; salinisation / desertification of soil; can’t grow crops; poverty related illness; migration away; 2 Question Answer Marks 1(c)(iii) cost; silting of river lower down / reduced flow; environmental damage during building; displacement of people; noise / visual pollution; loss of habitat; leads to loss of biodiversity; will flood some areas; 3 1(d) loss of insects; beneficial insects affected; biomagnification - increased concentration the higher the animal is in a food chain; bioaccumulation - accumulation of chemical in a particular species affects non-target species as alternative to loss of insects; harms other species; pollution risk to water stores / air; 3

This question in 8291/22 Oct/Nov 2021

4 Scientists on the international space station (ISS) get some of their water from the Water Recovery System (WRS). WRS uses waste water from respiration, sweat and urine and recycles this into drinkable water. It can produce up to 127 litres of recycled drinking water each day and can recycle 93% of the waste water. Each scientist on the ISS uses 49 litres of water per week for drinking, preparing food and personal hygiene. (a) (i) On a 60-day ISS mission there are five scientists. Calculate whether the WRS can provide all of the water the five scientists need. Show your working. [2] (ii) One litre of water has a mass of 1 kg. Suggest reasons why the water required by the scientists is not transported from Earth to the ISS. … … … … [2] (iii) Some of the waste water used by the WRS comes from respiration. Explain the meaning of aerobic respiration. … … … … … … [3] (b) The WRS uses a process called distillation to remove impurities from the waste water. Electricity is used to break down any organic matter. The process needs very high temperatures and pressures. Globally, one in three people do not have access to safe drinking water. Discuss the benefits and limitations of using the WRS to provide safe drinking water to people on Earth. … … … … … … … … … … [5] (c) Fig. 4.1 shows a solar still. A solar still uses processes in the water cycle to produce drinking water. Sun clear plastic dome salt clean water water collection Fig. 4.1 Use Fig. 4.1 and processes in the water cycle to explain how the solar still can produce drinking water. … … … … … … [3] (d) Explain how a lack of water can lead to malnutrition. … … … … … … [3] [Total: 18]

18 marks

Mark scheme: 4(a)(i) yes because per day: M1 (49  7 =) 7 (litres) needed per person a day; M2 (7  5 =) 35 (litres) needed for all the scientists a day (which is less than WRS 127 litres produced each day); OR total for 60 days: M1 (420  5 =) 2100 (litres) total needed for 60 days and 5 scientists; M2 (127  60 =) 7620 (litres) WRS produces in 60 days; 2 Question Answer Marks 4(a)(ii) any two from: M1 weighs too much; M2 requires a lot of energy to carry; M3 takes up too much space / difficult to store; 2 4(a)(iii) any three from: M1 chemical reaction (in cells); M2 that breaks down glucose; M3 requires oxygen; M4 releases energy; M5 produces carbon dioxide AND water; 3 4(b) max [4] benefits: M1 do not need a source of water / suitable in arid areas / can be used during drought / idea that dirty water can be used; M2 no wastage of water; M3 efficient (as 93% of water can be recycled); M4 idea that method or distillation is reliable; max [4] limitations: M5 people might not use it / not popular; M6 because do not like idea of drinking recycled urine etc; M7 requires energy / not everyone has access to electricity; M8 requires (specialist) equipment; M9 requires maintenance; M10 people will need training on how to use WRS; 5 4(c) M1 Sun heats (salt) water; M2 water evaporates; M3 (evaporated) water condenses on (inside of dome); 3 4(d) M1 reduces crop yield / crops need water to grow / idea that water needed for photosynthesis; M2 crops die / livestock die / livestock need water to live; M3 leads to food shortages / food insecurity; 3

This question in 8291/21 May/June 2023