User interface language: English | Español

Date May 2015 Marks available 7 Reference code 15M.2.SL.TZ0.5
Level Standard Level Paper Paper 2 Time zone Time zone 0
Command term Discuss Question number 5 Adapted from N/A

Question

A hydro-electric power plant is planned that will involve the building of a large dam across a river. This will result in the flooding of land upstream and regulation of the river flow downstream. The reservoir created by the dam will provide a water supply for the local community.

Outline two indirect methods that could be used to measure the impact on the river ecosystem of dead organic matter from the flooded vegetation and soils.

[4]
a.

Discuss how effective an environmental impact assessment for this project may be in protecting the local environment.

[7]
b.

Discuss how a Deep Ecologist and a Cornucopian may differ in their approach to this project.

[7]
c.

Markscheme

Please note: although "quality of expression" marking is no longer used in exams, this question from a past syllabus may still be useful for student practice.

 

use a Biotic Index/calculate the Biotic Index;
collect (many) samples from the lake/river systematically / from both upstream and downstream / at various intervals along a transect/ along the river;
over at least a year / twice a year;
identify the species (usually macroinvertebrates) using keys/photo charts;
and measure their abundance;
classify species into (pollution) tolerant, (moderately tolerant) and (pollution) sensitive;
count how many taxa/species fall into each class/category; [3 Max]

measure biological oxygen demand/BOD/Dissolved Oxygen;
sample the water using an appropriate kit/device/probe;
take initial and a final dissolved oxygen reading / take (at least) 2 recordings (initial & after 5, 7 or 10 days);
the difference between the initial and final reading is the BOD / calculate by appropriately graphing the data (DO values);
The higher the BOD the more organic matter/Dead Organic Matter is in the water; [3 Max]

 

[4 max]

a.

Please note: although "quality of expression" marking is no longer used in exams, this question from a past syllabus may still be useful for student practice.

 

The sub-headings below are for guidance only. Credit should be given for the Marking points whether the student identifies them under these titles or not.

 

Baseline study:
provides an inventory of social/cultural aspects / keystone/red-listed species/unique habitats that are of particular value;
this can help focus/organise/prioritise protective strategies;
but …it is time-consuming/expensive exercise;
may be biased if carried out by surveyors under employment of developer;
however the inventory may miss some species due to lack of funding/expertise / done fast as project deadlines are pressing;

Assessment of potential social and ecological impacts/benefits:
provides a holistic evaluation;
allows input from all stakeholders;
comparing to similar projects (already executed) would increase the validity of the EIA;
but …may be dominated by majority/commercial interests;
political interference may occur;
ecosystems are complex/newly formed and thus it is difficult to predict the potential impacts of a development on the ecosystem

Recommendations/Mitigations:
these are designed to limit impact/protect the environment;
the EIA report is a public document and allows public to disagree;
...may result in changed/modified construction techniques;
in some countries the EIA is advisory while in others it is compulsory and so may determine the implementation of mitigation strategies;
flooded area/lake/water reservoir should be designed to allow recreation activities / provide shelter for migratory birds / form a new ecologically sound habitat;
but …they depend on effective enforcement;
overall project may be so large that some/a lot of ecological destruction will be done (even if the EIA is “ perfect”);

Monitoring of impacts during development:
help to ensure developers were keeping to recommended procedures/ development before damage is irreversible;
alert authorities to any unforeseen damage to environment;
but …this again is time-consuming/expensive;
despite raising concerns nothing may be done to stop the impact;
evaluation of social/ecological impacts after the development:
would inform plans for any necessary restoration;
enables responsibility/costs for this restoration to be passed on to developers;
but …not all damages are restorable/reversible;
any penalties may simply be absorbed by developers as part of cost;
developers may press the government to avoid paying for restoration / pass the cost to the taxpayers;

 

Otherwise, award [6 max] for marking points above, and [1 max] for a clear conclusion that is justified by points raised.

Note to examiners: An isolated statement/opinion e.g. “EIAs are very helpful” should not be considered as a valid conclusion. A valid conclusion may, however, be stated within the body of the response rather than at the end, and may involve some balanced decision:

e.g. An EIA would be effective only if there is political will / enough funding / local pressure for its implementation; [1 max]

Award [2max] for whole question if response just describes what an EIA is with no reference its effectiveness.

[7 max]

b.

Please note: although "quality of expression" marking is no longer used in exams, this question from a past syllabus may still be useful for student practice.

 

Deep Ecologists believe in innate rights/biorights of living organisms;
…and that humans should have minimal impact on other species/ecosystems;
Natural processes are more important than human societies / humans should observe natural laws;
Cornucopians believe humans have an unqualified/unlimited right to exploit the environment;
…and technology will be sufficient to overcome any issues arising;
will prioritise pro-growth/development goals in the justification of a project;

Award up to [2 max] for general description of value systems ([1] for each).

 

Deep Ecologists’ approach to HEP project [3 max]:
Deep Ecologists would oppose the project because…
…building an HEP would be an example of materialism/unrestrained resource use that is against their beliefs;
…a large dam will disturb natural processes/ecosystems which is unethical;
…biorights of native species will be infringed through flooding upstream/changing flow downstream;
…local cultural values (e.g. river sanctity/”river festivals”) might be offended by interfering with the river;
…animal/human rights of free access to water would probably be infringed by administration of HEP/reservoir;
they would be against large-scale production plant/would propose smaller unobtrusive renewable energy sources;
they would be against centralized energy sources/ would propose community based, smaller scale, energy sources;

Cornucopians’ approach to HEP project [3 max]:
Cornucopians would be in support of project because…
the lake/reservoir would “improve” environment for human use e.g. recreation/more reliable water supply;
HEP would be an efficient power supply to increase standard of living/further technological growth/development;
it would provide a technological solution to problems of fossil fuel use;
any ecological issues/disturbances from HEP could be resolved through human ingenuity/further technology;
possible ecological/cultural losses would be outweighed by potential benefits to the community/society;
with appropriate scientific design/development, lake/reservoir could increase biodiversity (e.g. aquatic species/migratory birds/new habitats);
centralised management/regulation is more efficient/reliable at regulating resource use/maintaining sustainability;

 

Note to examiners: If candidates have understood the value systems (Deep Ecologists and Cornucopians) the wrong way round, but their responses are consistent with the two opposing views, award [3 max].

 

While some of the above reasons attributable to Deep Ecologists/Cornucopians may be common to other EVS, no credit should be given to responses that explicitly address other EVS instead, or to reasons that are exclusively attributable to other EVS

Otherwise, award [6 max] for marking points above, and [1 max] for a clear conclusion that is justified by points raised.

 

Conclusion mark:
An isolated statement/opinion e.g. “a deep Ecologist would object the project whereas a Cornucopian would support it” should not be considered as a valid conclusion. A valid conclusion may, however, be stated within the body of the response rather than at the end, and may involve some balanced decision:

e.g. From these arguments we can see that the approaches of deep ecologists and cornucopians are at opposite ends of a spectrum, which is why a more central position, such as environmental managers/soft ecologists, is likely to achieve more success; [1 max]

[7 max]

Expression of ideas [2 max]

c.

Examiners report

The candidates either knew the answer to this question and gained most/all the marks or they had no clue what to answer. A significant number could name two indirect methods but then gave no measurement method.

a.

Candidates often misread this question and only described an EIA rather than discussed the effectiveness of using one. For the candidates who did discuss they generally gained a number of marks and mentioned both positives and negatives of using an EIA. All the candidates did link their answers to the project mentioned in the question. This was good to see.

b.

Most candidates could distinguish between a deep ecologist and a cornucopian to gain some marks. Only the stronger candidates were able to adequately discuss their approach to the hydro-electric power plant and give a reasonable conclusion. A few candidates confused the two environmental philosophies.

c.

Syllabus sections

Topic 1: Foundations of environmental systems and societies » 1.4 Sustainability
Show 30 related questions
Topic 1: Foundations of environmental systems and societies

View options