SECTION A

Hydrology and fluvial geomorphology 1 Fig. 1.1 is a photograph which shows the High Country Rivers, New Zealand. (a) Name the type of river channel shown in Fig. 1.1. [1]

Braided channel

(b) Draw a cross-section of the river channel from X to Y shown in Fig. 1.1. Label the main features. [4]

(c) Suggest reasons for the formation of the channel type shown in Fig. 1.1. [5]

Atmosphere and weather

2. Fig. 2.1 shows average solar radiation and average global surface temperature change, 1910–2010.

(a) State the year when average solar radiation is the highest as shown in Fig. 2.1. [1]

1954

(b) Compare the trends in average solar radiation and average global surface temperature change shown in Fig. 2.1. [4]

There is a gradual increase in both the average solar radiation and average global surface temperature from the year 1910 to 1930. From 1930 to 1940 the average global surface temperature peaks then decline from 1940 to 1948 while the average solar radition remains constant. Average global surface temperature then increases from 1948 to 2010 from 0.2 to 0.9 while the average solar radiation declines from 1966 to 2010.

FROM MS

• Both average solar radiation change and average global surface temperature change have similar rising trends initially after 1910 with solar radiation reaching a minor peak ten years later than temperature change (1940 v 1950) • Solar radiation then declines rapidly and then a constant fluctuation whereas temperature change embarks on a continuous rising trend

(c) Suggest reasons for the trend in average global surface temperature change shown in Fig. 2.1. [5]

An increase in the percentage of greenhouse gases in the atmosphere due to industralisation has resulted in human activities such as the burning of fossil fuels like coal and natural gas becoming more prevelant. This has cause the greenhouse effect

The greenhouse effect is the process by which absorbed short and long wave radiation from the sun and the earth is re-radiated towards the earth, warming the planet’s surface to temperatures above what it would normally be.

FROM MS

The explanation will be in terms of the enhanced greenhouse effect. The processes behind the increasing greenhouse gas concentration in the atmosphere, the trapping of outgoing radiation and the nature of the relevant gases should be discussed (carbon dioxide, methane, aerosols, etc.). An interesting point is that the trends are similar up to 1940. It is after that date that temperature change diverts. This suggests that the enhanced greenhouse effect begins to assert an influence at this point. Note expansion of industry, deforestation, fossil fuels, etc.