NYJC Prelim H2 GEO 9751 P1 Answer

NYJC H2 Geog Paper 1 Prelims 2018 Mark scheme Section A – Tropical Environments 1 (a) Explain why tropical climates vary spatially. [12] Indicative content: Students will be able to explain why tropical climat es (humid and arid tropics) differ from place to place in terms of temperature and pr ecipitation even though the region is located in an area of insolation surplus. Slight diffe rences in temperature patterns can be made to the effects of long term factors like lati tude, height above sea level, land and sea, geographic position and ocean currents as well as local ones like cloud cover. In explaining the greater variations in precipit ation patterns, students will explain the role of the Hadley cell (factor of latitude in affecti ng primary pressure cell s), topographic features resulting in differences between windward and leeward slopes, continentality effects and ocean currents. A higher level response will include students’ ability to finely differentiate between the humid and seasonally humid tropics’ (A m and Aw) with regard to rainfall patterns (A m being coastal will have more rainfall from onshore winds during summer monsoon than Aw being continental interiors for same latitude loca tions). Top marks will be awarded to students who are able to bring in the ro le of humans in affecting clim ates via the ur ban heat island effects i.e. cities as contrasted to surrounding rural areas. Levels marked using H2 generic level descriptors for 12m SEQ sub-part (a). 1 (b) To what extent can the successful management of the impacts of a flood result from the immediate response to such an event? [20] Indicative content: To begin with, students should provide the definit ion of flooding. The focus of the question lies in the ‘immediate response’ to a fl ood event and whether it led to successful management with support from case studies i. e. alleviating the negative impacts of flooding. So, what constitutes an immediate response? A clear description of ‘immediate response’ which is indeed ‘search and rescue’ often in helicopters and boats is required. Having dealt with the immediate, then short term responses like water supplies, housing, shelter and aid in the form of food and blankets etc. can be discussed. Mid-term response measures will include re-housing, insurance payouts and repair of infrastructure. However, for su ccessful management, it is necessary to mention the need for longer-term responses like hard and soft engineering techniques, community preparedness and insurance schemes . Countries that are deemed as well prepared would have also invested time and money to do flood prediction as this not only provides time for evacuation efforts but al so aid in the evaluation of the adequacy of current flood protection structur es in their countries. Contex tualised examples of both successful and unsuccessful countries in flood management are needed. A higher response to flood management is to look beyond the channel such as management of the whole drainage basin. This wi ll help increase lag time and lower peak

2 Higher 2 Geography / 9751 / 01 discharge. Measures include controlling the rate of tropical deforestation within the catchment and the management of pluvial flooding due to rapid urbanisation. Noting that flooding after all is a climate led event, it is important for students to recognise that even developed countries are unable to guard agains t high magnitude, low frequency flooding despite having everything in placed. The challenges brought about by climate change such as stronger and more frequent tropical storms only puts more countries at risk in particular the economically weaker countries. Possible synoptic links: Theme 1.1 Storm runoff generation, Theme 2. 1 Role of the Stat e, Theme 3.1 Climate change due to enhanced greenhouse effect and T heme 3.2 Urbanisation and pluvial floods. Levels marked using H2 generic level descriptors for 20m SEQ sub-part (b). 2 (a) Explain the nature of flows and stores occurring in the humid and arid tropics. [12] Indicative content Students will show the understanding that flows and st ores are affected by climate. Indeed climate affects hydrological pr ocesses on a regional scale which in turn determines the nature of flows and stores. In order to show the impact of clim ate, students will have to provide a brief description of t he climatic conditions for both regions. As both climates are at the extreme ends of each ot her in terms of precipitati on (though they may exhibit the same high mean annual temp), students will argue that flows and stores of both regions will likely to be affected by input rather than output. The factor of pr ecipitation often plays an overriding role in determining the nature and amount of flows and stores. By this default, both climatic belts should see more differ ences in flows and stores as compared to similarities. A higher level response will include students ma king a finer distinction between climates within the humid tropics as A m and A w receive a more seasonal precipitation pattern as compared to Af. Students will be able to articulate the te mporal differences in the nature of flows and stores in their discussion of the two sub-types. In addition, they will recognize the impact of human activities e. g. deforestation, extractive industries as well as local factors such as geology and relief in altering the nature of flows and stores. Levels marked using H2 generic level descriptors for 12m SEQ sub-part (a). 2 (b) Discuss the factors that contribute to the formation and development of meandering and braided channels. [20] Indicative content Students will explain the influenc e of a variety of factors that contribute to both the formation as well as the development of meandering and braided channels. Climate remains the primary factor as it controls the amount of disc harge which in turn affects the velocity of the river to do its work – eros ion, transportation and deposition. However, climate alone will not be able to explain fully the two types of channel patterns. Local factors such as geology, abundant bedload and chann el slope must be considered to form

3 Higher 2 Geography / 9751 / 01 the complete picture. Climat e together with local factors combine to control water discharge, erodibility of the channel banks and sediment supply. A higher level response will include how time as a factor could alter the shape of meandering channels such as the formation of cut-offs and ox-bow lake. Likewise, human activities and climate change too have an impact on channel patterns. Both of these factors may create positive feedback loops. Examples could include the impact of extractive industries such as the mining of mineral ores as well as rapid deforestation which have led to high sediment load being disc harged into the waterways. This overloads the channel and cause sedimentation to occur resulting in meandering channels becoming braided through time. Similarly, as climate bec omes drier, the decr ease in discharge will inevitably reduce channel velocity, incr ease deposition and hence braiding. Hard engineering methods that incr ease the channel gradient th rough straightening for flood relief may also cause channels to braid. Possible synoptic links: Theme 1.2 Deforestation, Theme 2.2 Extractive industries and Theme 3.1 Climate Change Levels marked using H2 generic level descriptors for 20m SEQ sub-part (b). 3 (a) Explain ways by which Global Production Networks (GPNs) are able to remain competitive in rapidly industrialising countries. [12] Indicative conte