SRJC H2 GEO P1 2018 answer scheme

1 Name: _____________________________________ CG: ________ Date: ________________ SERANGOON JUNIOR COLLEGE JC2 H2 P1 GEOGRAPHY 2018 Preliminary Examination Answer Scheme Rubric for 12m Essays Level Marks Descriptors 4 10-12 Response is consistently analytical and comprises purposeful explanations. Response addresses the question fully using accurate and detailed knowledge. Depth of relevant knowledge and understanding is evident throughout. Response is coherent and use of terminology is accurate throughout. 3 7-9 Response is analytical and explanatory rather than descriptive. There is a clear focus on the question. Response demonstrates relevant knowledge and understanding. The response is coherent and the use of terminology is mostly accurate. A (75%) : 9 B (67%) : 8 C (58%) : 7 2 4-6 Response includes analysis and explanation but is generally dominated by description. Response reflects understanding of the question and is generally relevant. Some parts of the response may be unclear. Use of terminology is limited. 50% (D) : 6 42 % (S) : 5 33 % (U) : 4 1 1-3 Response lacks focus on the question. Response is generally fragmentary and lacks a clear structure and organisation. There may be many unsupported, brief or incomplete assertions and/or arguments with some inaccurate use of terminology. 0 0 No creditworthy response.

2 Rubric for 20m Essays Level Marks Descriptor 5 17-20 Response is perceptive, logical and has strong evaluative elements. Evaluation is relevant and comprehensive. Strong evidence of synoptic thinking where knowledge from different topics is synthesised purposefully. Use of detailed and accurate knowledge reflecting depth of understanding of the subject content. The argument or discussion is coherent and well supported by relevant material. Use of terminology is accurate. 4 13-16 Response displays a sound evaluative element. There is some evidence of synoptic thinking through synthesising knowledge from different topics. Response is generally focused on the demands of the question and features accurate knowledge, reflecting depth of understanding of the subject content. The argument or discussion is coherent and supported by relevant material. Use of terminology is accurate and appropriate. 3 9-12 Response is broadly evaluative rather than descriptive. Response addresses the questions and features accurate knowledge, reflecting some understanding of the subject content. Argument or discussion is mainly coherent and supported by material which is largely relevant. Use of terminology is relevant and mostly accurate. 12 B • Content accuracy • Rigour of elaboration (use of relevant statistics, reference to models, use of technical terms) for most parts of the essay • Addressing the question consistently • Clear evaluation shown in selected parts of essay (clear argument, supporting evidence, alternative perspectives 11 C • Content accuracy • Rigour of elaboration (use of relevant statistics, reference to models, use of technical terms) for most parts of the essay • Addressing the question consistently • Attempt at evaluation (clear argument, supporting evidence, alternative perspectives 10 D • Content accuracy (some CE) • Rigour of elaboration for some parts of the essay • Addressing the question for most parts of the essay • Attempt at evaluation (clear argument, supporting evidence, alternative perspectives) 9 E • Content accuracy (some CE) • Addressing the question, but may veer off in some parts • Attempt at evaluation ( but superficial or hypothetical) 2 5-8 Response is largely descriptive. Response attempts to provide an argument to address the question. The weakest responses in this level may lack balance and/or depth. Response structure is broadly coherent but may lack clarity. Some lapses in use of terminology though generally accurate. 8 (S) , < 7 (U) 1 1-4 Response lacks focus on the question and may be largely irrelevant to it. Response is fragmentary and lacks clarity. There may also be unsupported assertions and/or arguments with limited or no use of relevant terminology. 0 0 No creditworthy response.

3 1 (a) Explain the main land surface geomorphological processes operating in the humid tropical climates. [12] Geomorphological processes are those that bring about a change in the morphology of landforms and they are influenced by climate. Humid tropical regions would include : - all-seasons rain equatorial regions (Af) - seasonal rainfall monsoon (Am) and savannah (Aw) regions Dominant geomorphic processes: identify and explain 1. Chemical weathering 2. Mass movement 3. Surface erosion a. on the plains of Aw Surface erosion is most effective in the tropical savannah (Aw) climate - Limited vegetation cover (mainly grassland) which offers little protection - High intensity rain which generates sheet-floods during the summer monsoon erodes surface sediments from the uppermost layers of the regolith in the process called exhumation - the smooth surface of the savanna plains is progressively being lowered and leads to the gradual exposure of the basal surface of weathering which leads to large-scale exfoliation by dilatation b. Surface erosion in other humid tropical regions - on deforested surfaces of the rainforest (Af) and in areas of weak, easily eroded clays where the kinetic energy of high intensity rain causes rainsplash and rill erosion, and where the rills flow together, causing gully erosion. These gullies dissect slopes forming badland topography. 1 (b) Discuss the contribution of events in Pleistocene times to the present-day landforms of tropical regions. [20] SCRIPTORS The tropics, like the rest of the world, underwent repeated changes during the Pleistocene epoch which lasted from 2.6mllion to 11,700 years ago which was then fo llowed by the early Holocene epoch. These changes included changes in climate, sea level fluctuations and tectonic uplift. The geomorphological effects of such changes were enormous. While the geologic past is a good guide, for understanding current tropical landforms, it is essential to acknowledge that the processes operating under present climatic conditions also cause geomorphic effects. Event 1 : Climate change Event 2: Tectonic uplift and its influence on karst landforms Event 3 : Sea level fluctuations Event 4 : Role of present day processes

4 2 (a) Explain the effects of geology and changes in base level on the long profiles and cross profiles of river valleys. [12] IPTOR VEL MAR LONG PROFILE General shape is concave upwards. Some show regular concave section separated by convex section. Some show steeper overall gradient than others Geological reasons for the irregularities along the LP 1. Resistant rock outcrops present across the stream 2 - Differences in rock resistance Structural knickpoint along a LP 3. Differences in rock properties (lithological variations) and the effect on the graded profile. Even after the irregularities have been smoothened out , differences in the rate of supply and calibre of the sediment from different rocks may affect the nature of the graded profile. 4- Downstream decrease in the size of particle/sediment size (calibre) 5- Irregularities at a local scale : pool and riffle sequence of a straight/meandering channel A riffle-pool sequence also contributes to the irregularities of a LP. Riffles are formed in shallow areas by coarser