Cambridge A Level Environmental Management (AS only) 8291 — 2019 May/June Paper 2 · Variant 2

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]

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

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2 (a) The Great Barrier Reef is the world’s largest coral reef ecosystem. Fig. 2.1 shows the areas of the Great Barrier Reef monitored for bleaching in 2016 and 2017. Bleaching events turn the coral white due to the death of algae within coral. 2016 2017 N N Key most severe bleaching no or negligible bleaching Cairns Cairns Townsville Townsville Mackay Mackay 0 500 0 500 km km Fig. 2.1 (i) Describe two differences in the coral bleaching in 2016 and 2017 shown in Fig. 2.1. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) Suggest two human activities which could directly cause damage to the coral. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (b) Fig. 2.2 is an extract from a report about coral bleaching of the Great Barrier Reef. Aerial surveys have found that two severe bleaching events in 2016 and 2017 affected two- thirds of the Great Barrier Reef. This phenomenon is mainly caused by increases to the sea surface temperature. Scientists using aerial surveys recorded bleaching at 800 individual coral reefs across 8,000 km. The results show the two consecutive mass bleaching events have affected a 1,500 km stretch, leaving only the reef’s southern third undamaged. The 2017 event spread further south, and was most intense in the middle section of the Great Barrier Reef. The 2017 mass bleaching, second in severity only to 2016, has occurred even in the absence of an El Niño event. Mass coral bleaching has occurred on the reef four times in recorded history. Fig. 2.2 (i) With reference to Fig. 2.2, explain what has led to the mass bleaching of the coral. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) Suggest two ways, other than aerial surveys, scientists monitor changes in the coral reef. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... [2] (c) Fig. 2.3 is part of a food web for a coral reef such as the Great Barrier Reef. sea eagle reef shark sea turtle large fish jellyfish sea horse small fish molluscs coral zooplankton krill phytoplankton Fig. 2.3 (i) With reference to Fig. 2.3, suggest the effects that an increase in jellyfish numbers might have on this coral reef food web. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [4] (ii) The Crown of Thorns Starfish is an invasive predatory species which feeds on coral. Suggest how an invasion by these starfish might affect the food web shown in Fig. 2.3. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [4] (iii) Suggest strategies to control the population of the Crown of Thorns Starfish. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [4] [Total: 20]

Mark scheme: 2(a)(i) more areas of severe bleaching; previously affected areas (2016) are larger; damage spreading further north / south; southern area remains undamaged; max 2 2(a)(ii) diving; boating damage (contact); boating damage from nets / lines / anchors; pollution; named pollutant; coral mining; overfishing; max 2 2(b)(i) increased global warming / climate change; leads to rising sea temperatures; El Nino affects sea temperature; and leads to increased bleaching; complex chemical changes in the water lead to increased coral bleaching; acidification; max 2 2(b)(ii) satellite imaging; aerial photos; dive monitoring; monitoring of sea temperatures; colour chart testing; max 2 2(c)(i) increased phytoplankton; decreased zooplankton; reduction in small fish; reduction in molluscs; increased coral; food web becomes unbalanced; likely increase in top predators / reef shark / sea eagle; max 4 Question Answer Marks 2(c)(ii) damage / kill large areas of coral; reduce biodiversity of coral; less coral available for secondary consumers; reduction in species in the food web; named example; less food for top predators; loss of habitat / shelter for species in the food web; max 4 2(c)(iii) collection / removal by divers; allows reduction of numbers and provides opportunities to inspect the progress / state of the reef; kill by chemical injections; some concern over chemicals entering the food web; disrupt reproduction with hormones; population gradually declines as reproduction rate falls; introduce predatory fish; these eat the starfish but could interfere with the food web; a robot has been designed to catch and inject the starfish; less need for human interaction with the reef and the species there; max 4

More questions on Ecosystems

3 Fig. 3.1 is an extract report on the success of rewilding projects in the United Kingdom. Rewilding is a conservation method which restores an area to its natural uncultivated state. Examples of rewilding projects which have significantly reduced flood risk in the UK include: • Uplands replanting project: moorland grasses, heathers and other plants were replanted to increase the retention of water in peat bogs. • Beaver reintroduction: beavers (an animal that builds woody dams in small rivers) were reintroduced stimulating the revival of natural wet woodland. They have significantly increased water storage while slowing the flow of water downstream. Fig. 3.1 (a) With reference to Fig. 3.1 suggest the advantages and disadvantages of these rewilding projects. [10] (b) Using examples, evaluate methods to protect areas and their ecosystems through the creation of national parks, conservation areas and similar schemes. [30] [Total: 40]

More questions on Managing the conservation of biodiversity

4 Lake Chad is a large lake in northern central Africa that provides fresh water to around 30 million people in the countries of Chad, Cameroon, Niger and Nigeria. In 1963, Lake Chad covered an area of approximately 25 000 square kilometres. Fig. 4.1 shows changes to the area of Lake Chad from 1963 to 2007. Lake 1963 1973 1987 Chad N N N Chad Chad Chad Niger Niger Niger Nigeria Nigeria Nigeria Cameroon Cameroon Cameroon 1997 2007 Key N N Chad Chad water Niger Niger area of lake in 1963 vegetation country boundaries Nigeria Nigeria Cameroon Cameroon Fig. 4.1 (a) Describe the change in Lake Chad shown in Fig. 4.1 and suggest the effects of this change on the human population living around Lake Chad. [10] (b) Outline factors which may cause diminishing water supplies. Using examples, assess strategies to manage the conservation of natural water resources. [30] [Total: 40]

Mark scheme: 4(a) Lake Chad has shrunk dramatically in size, with the rate of loss accelerating. The loss of water has been from the north and east. Human population relies on the lake for water to support and irrigate crops, for drinking water for animals and themselves, and for fishing (both for food and as a living). Loss of water has also led to increasing desertification in the area. Please use level descriptors 1 10 4(b) The question requirements are: • To outline factors which lead to the reduction of water supplies and stores • To describe how the loss of water changes the ecosystem and affects the lives of the people • To suggest strategies to manage the conservation of such water resources. Causes include loss of flow in rivers due to dams which also increase silting, increase in human population leads to increased use of water for irrigation, water for livestock and human drinking water. The change in weather patterns such as monsoon rains which recharge the lake failing leading to drought conditions. Deforestation, over-extraction from aquifers, pollution including global warming leading to loss of ice stores. Strategies to include seeking international cooperation for the diversion of rivers to refill lakes, encourage HEP dams to release water in regular flows, improve dredging processes to prevent silt build up, build efficient irrigation systems for farms to reduce waste, education of the population in water conservation e.g. grey water/recycling water, rain-water collection, desalinisation. Please use level descriptors 2 30

More questions on Managing the conservation of biodiversity

5 Fig. 5.1 shows a major hydroelectric dam, and a map of the location of this dam in China. N Yellow Sea Jialing Nanjing Wuhan Shanghai Yangzi Chongqing 0 600 km Key Three Gorges Dam Construction Site area to be flooded city Yangzi river Jialing river Fig. 5.1 (a) With reference to Fig. 5.1 outline the advantages and disadvantages of generating power using a hydroelectric dam. [10] (b) Using examples, assess the problems of providing power through hydroelectric generation in countries at contrasting levels of economic development. [30] [Total: 40]

Mark scheme: 5(a) Advantages include ‘renewable’ tag as water isn’t consumed during the process, can generate power continually, can retain water for controlled release to allow generation during peak demand, and once constructed doesn’t generate waste or polluting by-products, they also provide recreational possibilities. Disadvantages include risk of earthquake damage, loss of habitats because of flooding, loss of biodiversity, disruption of fish migration patterns, disruption of human habitation or activities such as farming, pollution including noise pollution during construction, the loss of water flow downstream leading to increased silting, and they are very expensive to construct. Please use level descriptors 1 10 5(b) The question requirements are: • To understand the problems involved in constructing HEP dams • To distinguish between the problems faced by countries with different levels of economic development • To assess the relative impact of HEP schemes in countries with different levels of economic development. HEP dams are very expensive to set-up and countries with low economic development haven’t the resources to build and often rely on other countries for the construction costs e.g. China are building a lot of dams in Africa in return for access to mineral resources. The power generated doesn’t always benefit the local population, and often these are the people displaced by the construction. Jobs aren’t always generated locally as overseas workers are used. Costs escalate and projects overrun leading to long term financial losses and further weakening the local economy often for decades e.g. Brazil’s Itaipu Dam. More highly developed economies can afford the HEP costs but don’t always have the natural resources to warrant the use of HEP dams. They usually finish construction on time and within budget reducing the financial overburden. These countries also can afford mixed supply sources including solar and wind power. Please use level descriptors 2 30 Section B descriptor levels: Descriptor Award Mark Consistently meets the level criteria Mark at top of level Meets the criteria, but with some inconsistency Middle, mark to just below top mark Meets most of level criteria, but not all convincingly Just below middle, mark to just above bottom mark On the borderline of this level and the one below Mark at bottom of level level descriptors 1 Level one, 8–10 marks The response: • contains few errors • shows a very good understanding of the question • shows a good use of data or the information provided, where appropriate • provides a balanced answer Level two, 5–7 marks The response: • may contain some errors • shows an adequate understanding of the question • shows some use of data or the information provided, where appropriate • may lack balance Level three, 1–4 marks The response: • may contain errors • shows limited understanding of the question • shows little or no use of data or the information, where appropriate • lacks balance Section B descriptor levels: level descriptors 2 Responses: Level one, 25–30 marks • fulfil all the requirements of the question • contain a very good understanding of the content required • contain a very good balance of content • contain substantial critical and supportive evaluations • make accurate use of relevant vocabulary Level two, 19–24 marks • fulfil most of the requirements of the question • contain a good understanding of the content required • contain a good balance of content • contain some critical and supportive evaluations • make good use of relevant vocabulary Level three, 13–18 marks • fulfil some requirements of the question • contain some understanding of the content required • may contain some limited balance of content • may contain brief evaluations • make some use of relevant vocabulary Level four, 6–12 marks • fulfil limited requirements of the question • contain limited understanding of the content required • may contain a poor balance of content • may not contain evaluations • make limited use of relevant vocabulary Section B descriptor levels: Level five, 1–5 marks • fulfil a few requirements of the question • contain a very limited understanding of the content required • are likely to be unbalanced and undeveloped • evaluative statements are likely to be missing • make no use of relevant vocabulary

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