SAJC Prelim_H2_GEO_P2_mark scheme

SAJC 2018 H2 Geography Paper 2_Mark Scheme_pg 1 © SAJC 2018 9751/02/18 Prelims Section A Theme 4: Geographical Investigation 1 (a) With reference to Resource 1, describe the main changes made to the river channel, and explain how these are meant to reduce flooding. [5] Changes Reduce flooding because… • Vegetation on the river banks have been removed, and replaced by concrete [ 1 m ] Speeds up the flow, such that flood waters can be removed quickly (i.e. more efficient) downstream: • Reduction of friction between water and the banks (i.e. lowers roughness) • Concrete lining prevents bed or bank erosion, lowers sediment load of the river [ 2 m ] • The river has been widened (note that the natural river banks have been “pushed back” to closer to the buildings) [1m] • Capacity of the river has been increased, allowing more water to be contained within the channel, helping to prevent bankfull discharge from being exceeded [ 1 m ] (b) With the help of Resources 1 and 2, suggest a research question for the group to guide them in their investigation, and briefly explain why it is of a suitable scale. [3] Possible research question: [1m] • To what extent has the channelisation at the confluence of Rivers Klang and Gombak reduced the perception of flood risk among users of the area in its vicinity? Considerations: [not creditable directly, but must be reflected in the research qn] • Fixed variable – channelisation • Variable to be tested – perception of flood risk • Where? – Confluence of the rivers • Who? – Users of the area in the vicinity of the confluence (defined here as within 300m radius) Why it is of a suitable scale: [2m] • Geographical area is small, only 300m radius, which is a little over 0.28km 2 • There is sufficient resources in terms of manpower (20 students) that can be divided into enough teams (5 teams of 4) to be spread out within this area • A total of 4 hours over two evenings is reasonable amount of time to survey 50 members of the public (average one team surveys 5 respondents every evening) (c) With the help of Resource 2, outline the steps necessary for the students to obtain a representative sample they require for the survey. [4] There is no fixed way of sampling, but explanations should be given for the suggested approach. Considerations should include: • Where to conduct the survey (e.g. stratified sampling to select five locations based on characteristics such as distance from the confluence; landuse; etc) • Who to find as respondents (e.g. a blend of quota and convenience sampling to obtain sampling profile that is reflective of actual population by age, gender, etc)

SAJC 2018 H2 Geography Paper 2_Mark Scheme_pg 2 © SAJC 2018 9751/02/18 Prelims Level Marks Descriptors 2 3-4 Response demonstrates good to very good knowledge of sampling method(s). Outlines a clear plan with refe