RVHS Prelim_H2_GEO_P2_Soln

1 RVHS H2 GEOGRAPHY PAPER 2 PRELIMS 2018 1 (a) Suggest a suitable research question for this investigation about infiltration rates. [1] Key criteria: 1. clearly defined 2. capable of being researched 3. situated within manageable spatial and/or time scales Award 1m for any suitable research question. No marks if a hypothesis statement is given. e.g. How do raingardens impact infiltration patterns in urban areas in the tropics? (b) With reference to Resources 1 and 2, explain two potential risks associated with carrying out this geographical investigation and how the group might minimise each risk. [4] ‘Risk’ is defined as the threats to welfare and danger to life for the investigators. In the context, these may include: - Dangers associated with traffic because of proximity to the roads - The canal as a source of danger - Weather related risks (thunder storms, high mid-day temperatures) Award 2m for each elaborated risk and proposal for precautionary measures (c) Referring to Resource 2, explain how the students used the equipment to measure the infiltration rate at a data site. [5] 1. Operational steps to using the double-ring infiltrometer and explanation of rationale a) Plunging infiltrometer up to limit of the ring lid b) Filling the outer ring to prevent lateral diffusion of water c) Filling up to a standardised level and noting the fall in water level on the ruled markings on the infiltrometer for a standardised time. d) Refilling to the same level and repeating the measurement of water level fall in a standardised time (to maintain standardised pressure on the soil) for the number of times necessary 2. Precautionary principles (minimial disturbance of soil structure, timing and reading) a) Taking care to clear the sample site of irrelevant debris like rocks and litter which might compromise readings b) Minimising disturbance of soil structure by single, clean action of inserting the infiltrometer c) Avoiding parallax error by ensuring perpendicularity of the infiltrometer Point Marked: Award max 3m for pure description of steps without rationale (d) The students reflected that the findings might have been compromised by intervening factors. With reference to Resources 1, 2 and 3, discuss how the process of data collection could be improved. [7]

2 Indicative content: Intervening factors affecting accuracy / credibility of data: 1) Separation of data collection into 2 sittings compromises the comparability of the data collected. Ideal situation would have been collecting all data within the same sitting to ensure that relevant conditions like antecedent soil moisture are the same 2) random sampling might not have been the most suitable method for ensuring that the range of data collected is representative of the types of surfa ces found along segments A and B respectively (many types of surfaces) 3) Difficulties of measuring in a planted bed Sugge