2025 ACJC Prelims P2 Answers

© ACJC 2025 [Turn over READ THESE INSTRUCTIONS FIRST You should follow the instructions on the cover sheet. If you need additional answer paper, ask the invigilator. Write your index number and name on the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer Question 1 in Section A. Answer Question 2 in Section B. Answer one question in Section C. Start your answer to each question on a fresh sheet of answer paper. At the end of the examination, your answers should be separated and securely fastened into 2 bundles. Attach a cover sheet on top of bundle 2. • Bundle 1: Answers to Question 1. Name and index number to be clearly indicated on the first page of the answers. • Bundle 2: Cover sheet and answers to Question 2 and Question 3 or 4. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 5 printed pages and 1 blank page. ANGLO-CHINESE JUNIOR COLLEGE JC2 Preliminary Examination Higher 2 GEOGRAPHY 9173/02 Paper 2 16 September 2025 3 hours Additional Materials: Insert Cover Sheet Answer Paper

2 © ACJC 2025 9173/02/JC2 Preliminary Examination Answer Questions 1 and 2 and EITHER Question 3 OR Question 4 Section A Cluster 4 Fieldwork 1 There are plans to turn the coastal mangrove area around the Sungai Mandai Besar River in northern Singapore into a nature park that will be named the Mandai Mangrove & Mudflat Nature Park. A group of five students wanted to assess the flood risk around the Sungai Mandai Besar River. The river is concretised into a canal for most of its course except for the short stretch at the river mouth. The hypothesis the students chose: ‘Fluvial flood risk is lower near the river mouth than around the canalised parts of the Sungai Mandai Besar River.’ To assess the flood risk of the areas surrounding the river, the students collected data on infiltration rates and selected river variables. They collected data on a week day in December from 10 am to 4 pm. At each site, two students worked on the infiltration test, while three worked on collecting data on selected river variables. All five of them worked at Site A first. They were only able to start work at Site B after the thunderstorm ended at 3 pm. They collected infiltration data around Site B, and only the river velocity data at Site B. The equipment that the students used for their field investigation included: • A single-ring infiltrometer made of white plastic tubing with a diameter of 10 cm and a height of 30 cm • Two brightly marked half-filled plastic mineral water bottles as the velocity-floats • Two stop watches • A pail to fetch water from the river for the infiltration test For the infiltration test, the students c