2023 HCI J1 Promos Ans Key

HWA CHONG INSTITUTION JC1 Promotional Examination Higher 2 SUGGESTED ANSWERS AND COMMENTS Section A Answer both questions. Cluster 2 Tropical Environments 1 Resource 1 shows the Inter-Tropical Convergence Zone (ITCZ) and wind direction over the African continent in June to September, and January to March. The locations of Ouagadougou (12.4°N), capital city of Burkina Faso, and In Salah (27.2 °N), an o asis town in central Algeria, a re also shown in Resource 1. Resource 2A is a cross -section schematic diagram of the drainage basin system in Ouagadougou while Resource 2B shows that of In Salah. Resource 3A shows a mass movement that had occurred in Ouagadougou, and Resource 3B shows a mass movement that had occurred in In Salah. (a) Describe the changes in winds over Ouagadougou and In Salah from June to January shown in Resource 1. [4] Award 1m for changes, to a maximum of 2m for winds in Ouagadougou, and maximum of 2m for In Salah. Possible observation of changes in winds include:  Onshore or offshore: e.g. Ouagadougo experiences onshore winds from Atlantic Ocean in June, but offshore from dry continental interior in Jan.  Wind direction: e.g. In Salah experiences predominantly easterly winds in June, but in Jan, little/no winds as it is dominated by high pressure cell (b) With reference to Resource 1, suggest reasons for the differences i n rainfall characteristics between Ouagadougou and In Salah. [8] Award maximum of 2m for description of and differences in rainfall characteristics of Ouagadougou (marked seasonality of wet season in June, dry season in January) and In Salah (arid throughout year, with very low total annual rainfall) Award 1m for a valid suggested reason with an additional 1 to 2m for development of point. Maximum of 6m for explanation (as 2m is needed for description) Possible reasons:  Aridity of In Sal ah: dominance of high pressure belt shown by wind direction; ITCZ does not move into the region  Seasonality of rainfall in Ouagadougou: Onshore winds: moisture laden winds forced to rise over any elevation or possibly uplifted by ITCZ low, resulting in expansion of air mass, adiabatic cooling to saturation, forming rainclouds.  Proximity of Ouagadougou to ITCZ accounting for wetter climate (c) Describe the differences between the two drainage basin systems of Ouagadougou and In Salah shown in Resources 2A and 2B respectively. [4]

2 © Hwa Chong Institution 9173 / 01 / C1 Promo Exams 2023 Award 1m for each difference with an additional 1m for development comparing the two (only if applicable and clearly a development of point), to a maximum of 2m for each difference. Possible differences include:  Much higher water table in Ouagadougou than in In Salah (which is below level of river bed) 