Cambridge IGCSE Environmental Management 0680 — 2018 Oct/Nov Paper 4 · Variant 2

1 Mexico’s economy depends on modern manufacturing industries, agriculture and tourism. There are abundant reserves of oil, natural gas and minerals. Environmental problems include a shortage of clean drinking water, deforestation and desertification. (a) Mexico is the world’s largest producer and exporter of avocado fruit. More than 1.5 million tonnes are now produced each year. The state of Michoacan is the largest producer of avocado fruit in Mexico. The table shows climate data from a weather station in the centre of Michoacan state. month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec average monthly temperature 15.2 16.1 17.8 19.5 20.5 20.2 19.3 19.2 18.8 18.1 17.0 15.7 / °C average monthly rainfall 31 13 6 10 48 267 351 343 341 156 40 19 / mm (i) Calculate the annual average temperature range at this weather station. ...................................................... °C [1] The altitude of the avocado farms in this state varies from 1300 m to 2300 m. The decrease in temperature with increase in height is 0.6 °C per 100 m. (ii) Calculate the expected temperature difference between the highest and lowest avocado farms in the state. ............................................................[1] (iii) This weather station is at an altitude of 1920 m. Farm A is at an altitude of 1420 m. Calculate the average expected temperature at Farm A in April. Show your working. .......................................................°C [2] (b) The avocado trees produce flowers which then develop into avocado fruits. The main harvest starts in October. The avocado fruits on farm A are always harvested before farm B. Farm B is at an altitude of 2000 m. (i) State the name of the process that the avocado trees use to capture carbon dioxide. .......................................................................................................................................[1] (ii) Suggest why the avocado fruits are always harvested on farm A before farm B. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[2] (iii) Avocado trees cannot fix nitrogen from the air. Farmers add nitrogen fertilisers to the base of each tree every year between January and May. Using information from the table of climate data, explain why farmers add fertilisers at this time of year. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[2] (iv) Suggest the possible impacts on the environment if fertilisers are added to these avocado trees later in the year. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[3] (v) Suggest three reasons why farmers do not grow crops between the avocado trees. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... 3 ........................................................................................................................................ ........................................................................................................................................... [3] (c) Up to half of Mexico’s total avocado fruit production is exported each year. Suggest the benefits for the farmers and the government of exporting the avocado fruits. benefits for farmers ................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... benefits for the government ...................................................................................................... ................................................................................................................................................... ................................................................................................................................................... [3] (d) Avocado fruit production has increased in recent years due to demand. The table shows the changes in avocado fruit production between 2014 and 2016. 2014 2016 percentage increase area planted / ha 168 000 187 000 11.3 avocado harvest 1.47 1.64 / million tonnes .............................. (i) Complete the table. Show your working. [2] (ii) The increase in avocado fruit production has led to deforestation in several Mexican states. Describe how deforestation can result in soil erosion. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[4] (iii) To reduce the impact of deforestation scientists are trying to develop new varieties of avocado trees to increase the fruit yield per hectare. Suggest two ways new varieties of avocado trees can be developed. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... [2] (e) A student wanted to find out how much of the avocado fruit could be eaten. The seed and skin cannot be eaten. 10 skin cm edible fruit seed 0 The following method was used: • find the mass of one avocado fruit • cut the fruit in half and remove the seed • find the mass of the seed • remove the edible fruit from the skin • find the mass of its skin. mass / g whole fruit 307 seed 59 skin 56 edible fruit ..................... (i) Calculate the mass of the edible fruit. Write your answer in the table. [1] (ii) Calculate the percentage of the avocado fruit that can be eaten. .......................................................% [1] (iii) Suggest one safety instruction that should have been included in the method the student used. ........................................................................................................................................... .......................................................................................................................................[1] (iv) The people living on avocado farms eat avocado fruits every day. Suggest two ways the seed and skin could be used on a farm. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... [2]

Mark scheme: 1(a)(i) 5.3; 1 1(a)(ii) 6 (°C); 1 1(a)(iii) (19.5 + 3 =) 22.5 / 23 ;; (if answer incorrect, allow one mark for 0.6 × 5 = 3 (°C) [1]); 2 1(b)(i) photosynthesis; 1 1(b)(ii) any two from: Farm A warmer at a lower altitude / Farm B cooler at a higher altitude; faster growth (in warmer climate) / faster development; further details, e.g. rate of metabolism / flower earlier / ripen faster; 2 1(b)(iii) any two from: low average rainfall; so fertiliser not washed off fields; so fertiliser not wasted; so fertiliser can be absorbed (as tree grows); needed to develop, flowers / fruit; 2 1(b)(iv) any three from: fertilisers, leached / washed off field due to rainfall; (enters rivers / streams) causes eutrophication; algal bloom; which blocks light; death of plants due to lack of light; increase in bacteria; bacterial respiration; decomposition uses up oxygen; death of fish; disrupts, food chain / food web / reduction in biodiversity; 3 Question Answer Marks 1(b)(v) any three from: not enough light for growth of crops; too difficult to harvest between trees; cultivation, disturbs / damages trees; competition for water; competition for nutrients; difficult to control pests; economic comment such as, value of avocado crop enough to support farmer / increased cost of, labour / seeds / fertiliser if crops grown as well; 3 1(c) both benefits for farmers and benefits for the government must be covered for maximum credit: max two from, benefits for farmers: farmers, can always sell all the crop / have access to bigger market; make more money; invest in more, equipment / fertiliser / education / healthcare; max two from, benefits for the government: government collect taxes; improved, economic growth / GDP; so can spend money on infrastructure; 3 1(d)(i) (0.17 / 1.47 × 100 =) 11.56 / 11.6 (%) ;; (if answer incorrect, allow one mark for 1.64 – 1.47 = 0.17 [1]); 2 1(d)(ii) any four from: reduced interception; reduced infiltration; (increased) surface run-off; soil no longer held in place by roots; soil washed away; trees act as wind breaks; wind blows soil away; 4 Question Answer Marks 1(d)(iii) produce hybrids / by cross pollination / selective breeding; genetic manipulation / genetic modification / gene transfer / genetic engineering; 2 1(e)(i) 192; 1 1(e)(ii) 62.54 / 62.5 / 63; 1 1(e)(iii) be careful, with knife / cutting the fruit; 1 1(e)(iv) any two from: use seeds to grow more trees; use to make compost / manure; use as animal feed; 2

2 (a) Mexico is rich in mineral resources including copper ore. The table shows the world price of copper over a six-year period. year 2011 2012 2013 2014 2015 2016 price / 9600 7200 7400 6900 5400 4700 USD per tonne (i) Plot a bar graph of the data on the grid. [4] (ii) Describe the trend shown by the graph. ........................................................................................................................................... .......................................................................................................................................[1] (iii) Suggest two possible reasons for this trend. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... [2] (b) The life of a mine has four stages of operation. exploration development production closure The table shows information about some mines at different stages. mine mineral stage A copper, gold exploration B copper exploration C copper, gold production D copper production E copper, gold, silver development F copper, gold development stopped G copper closure (i) Suggest possible reasons why development at mine F has stopped. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[2] (ii) Suggest why an environmental impact assessment is required as the first stage in the development of a mine. ........................................................................................................................................... .......................................................................................................................................[1] (iii) Describe strategies that can be used to reduce the impact on the environment after closure of a mine. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[3] (c) The Angangueo underground mine in Michoacan state stopped production of copper, lead and zinc ores in 1992. Local people only earn money from tourism for part of the year as well as legal and illegal logging of the nearby pine forests. A mining company has applied to start production again. The plan is to extract 3000 tonnes of ore each day for the next 12 years. (i) Suggest why many people want the mining to start again. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[2] (ii) Suggest how this mining activity may reduce the impact of logging on the pine forests. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[2] (iii) There are two rivers and several streams flowing near the mine. Explain why some local people are worried about water pollution if mining starts again. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... .......................................................................................................................................[3]

Mark scheme: 2(a)(i) suitable linear scale; y axis fully labelled including units; x axis fully labelled; correct plots; 4 2(a)(ii) the price (of copper) decreases (with time); 1 2(a)(iii) any two from: too many copper mines operating / (world) oversupply of copper / recycling copper; less demand for copper; description of reduced demand, e.g. using alternative materials; local protests stop copper mining; 2 2(b)(i) any two from: deposit not as big as first thought; not going to be profitable; AVP, e.g. unforeseen geological / environmental issue, such as underground flooding / dispute over mining rights / land ownership; 2 Question Answer Marks 2(b)(ii) to make sure that mining can take place without doing too much damage to the environment / OWTTE; 1 2(b)(iii) any three from: holes can be filled with, waste rock / overburden; landfill; landscape / spoil heaps, can be shaped; covered with soil; and soil planted; use plants that absorb toxins; reference to, safe drainage through soil heaps; AVP, e.g. National Park / wildlife reserve; 3 2(c)(i) any two from: they want employment; all year round; better paid; named example of raising their standard of living, e.g. better housing / infrastructure; job security for 12 years; risk of being caught illegal logging; 2 2(c)(ii) any two from: stable income / mining better paid (than logging); so reduced logging; people do not need to do illegal logging to earn money; 2 2(c)(iii) any three from: mining produces toxic waste; their drinking water may become toxic; toxic materials kill the, fish / organisms in the river; could poison, humans / stock animals; reduce crop growth; 3 2(d)(i) select at random / stratified sampling / AVP; further description on how it is done, e.g. volunteer sampling; 2 Question Answer Marks 2(d)(ii) any two from: they earn money / it provides jobs (from working in hotels / tour guides / souvenir selling, etc.); to pay for, school / medical care / other named example; better infrastructure for everyone; help people learn another language; 2 2(d)(iii) any two from: (they think) the butterfly is being protected; and tourists cannot visit other sites / can only visit two, sites / zones / controlled areas; tourists only visit in winter; it is ecotourism; 2 2(d)(iv) question about tourism such as, Do you sell butterflies? / Do you earn money from tourists? / Do you work in tourism? / Do tourists want to see other species? ; 1 2(e) any two from: raise awareness of the butterfly within Mexico; and in other parts of the world the tourists come from; AVP, e.g. generates money for conservation; 2