1.1 Refer to FIGURE 1.1 showing stages in the development of a mid-latitude cyclone - NSC Geography - Question 1 - 2018 - Paper 1

The stage of development of the mid-latitude cyclone at X is known as the Wave or Formative stage.

The lowest air pressure recorded in stage Y is 1,000 hPa.

Mid-latitude cyclone Z is older than cyclone Y.

The stage of development of the mid-latitude cyclone at Z is the Occlusion or Occluded stage.

The evidence suggesting that the illustrated mid-latitude cyclone is in the Southern Hemisphere includes the clockwise rotation of air and the orientation of warm and cold sectors, with the warm sector facing northwards and the cold sector facing southwards.

The term used to describe mid-latitude cyclones that are linked to one another is 'Family of cyclones' or 'Cyclone families'.

Rivers that flow all year round are referred to as permanent rivers.

Exotic rivers flow during the rainy season.

Episodic rivers only flow after heavy rainfall or have an exotic nature.

The majority of rivers in South Africa are periodic.

In episodic rivers, the river bed is always below the water table.

The water table is always below the river bed in exotic rivers.

Periodic rivers flow all year round because they are fed by tributaries in high rainfall areas.

Permanent rivers are characteristic of interchanging seasons of high and low rainfall.

Sketch A indicates a winter condition.

Evidence indicating that sketch A suggests a winter condition includes the presence of snow or cold air masses, which are typical in winter months.

The inversion layer in sketch A forms when cold air sinks and resides below a layer of warmer air, leading to a stable atmosphere that can trap pollutants.

The position of the height of the inversion layer changes in sketch B due to variations in temperature and pressure; generally, it rises as temperatures increase.

The changing position of the height of the inversion layer over the plateau significantly influences climate conditions in South Africa's interior. During summer, the inversion layer is typically higher, allowing for better dispersion of pollutants and resulting in clearer skies. Conversely, in winter, the inversion layer descends, creating a stable atmosphere that traps cold air and pollutants, leading to increased smog and poor air quality. Furthermore, the inversion layer's position affects temperature variations, with warmer air sitting above colder air, stifling upward movement and increasing temperature inversions. This dynamic is crucial for understanding weather patterns, thus impacting agriculture, transportation, and public health.

Pietermaritzburg was a poor choice for city development due to its location on a valley floor, where pollution tends to concentrate and where natural resources may be less available.

Pollution levels are higher in winter due to temperature inversions, which prevent cold air from mixing and disperse pollutants, causing them to accumulate near the ground.

The local wind that causes the 'brown haze' to disappear is known as the Anabatic or upslope wind.

One characteristic of the Anabatic wind is that it rises along slopes, effectively carrying away fog and pollutants.

A labeled sketch should depict the rise of warm air along slopes, illustrating the movement direction of the wind and the formation of the local wind system.

The 'brown haze' is a safety hazard for motor vehicle users as it reduces visibility significantly, increasing the risk of accidents.

Drainage pattern A is known as a trellis pattern, while drainage pattern B is a rectangular pattern.

The underlying rock structure for drainage patterns A and B includes folded sedimentary rocks, mainly consisting of alternating hard and soft rock layers.

One similarity between drainage patterns A and B is that they are both influenced by the geology of the underlying rock structure.

A key difference between drainage patterns A and B is that A has tributaries that join the main stream at a 90° angle, while B has more irregular paths.

The tributaries in drainage pattern A are shorter because the steep slopes (altitudes) limit their growth and extension, causing them to join the main river quickly.

In drainage pattern B, the main streams having 90° bends is due to the influence of jointing and fracturing in the hard rocks that redirect water flow.

A delta is a landform created at the mouth of a river where it meets a body of water, formed by the deposition of sediment carried by the river's flow.

Evidence from the photograph indicating a delta includes visible sand deposits and the branching of the river into smaller channels as it approaches the sea.

The feature labelled A in the aerial photograph is a distributary.

Feature A, a distributary, forms when the river splits into multiple smaller channels moving away from the main river to distribute sediment across the delta.

Some coastlines are not suitable for delta development due to factors like strong tidal currents which can prevent sediment accumulation near the river mouth.

Deltas are ideal for farming due to the nutrient-rich sediments deposited by rivers, which enhance soil fertility. The flat topography of deltas facilitates easier irrigation and farming operations. Additionally, deltas typically have access to abundant freshwater sources. The diversity in microclimates within delta regions allows for the cultivation of varied crops. Furthermore, the relatively stable water supply during wet and dry seasons supports year-round farming. Farmers can benefit from the easy accessibility of transportation for goods, allowing markets to flourish. Overall, deltas support sustainable agriculture, providing food security for surrounding populations.