While visiting the South Island of New Zealand, you notice that conditions vary sharply across the island. The West Coast is very wet and receives between 600 and 1600 mm of rainfall per year, while the East Coast only receives about 640 mm of rain per year and is very dry. What best explains this regional difference in precipitation?

Question

A.  Proximity to Antarctica.
B.  The absence of inland lakes.
C.  The presence of a large river along the West Coast.
D.  The presence of mountains along the West Coast.
E.  Latitudinal differences between the East and West Coasts.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?

Gather Content
· What do you already know about precipitation?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

D.  The presence of mountains along the West Coast.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses precipitation.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.
 
Gather Content
· What do you already know about precipitation?
        o Regional differences in precipitation can occur because of rain shadows.
        o Deserts on land sometimes occur because mountain ranges intercept moisture-laden winds from the sea. When air flowing landward from the oceans encounters a mountain range, the air rises, and its moisture-holding capacity decreases because it becomes cooler at higher altitude, causing precipitation to fall on the mountain slopes facing the sea.
        o As the air—stripped of much of its moisture—then descends on the other side of the mountain range, it remains dry even as it is warmed, and as it is warmed its moisture-holding capacity increases, meaning it can readily take up moisture from soils and plants.
        o One consequence is that the two slopes of a mountain range often differ dramatically in how moist they are, and a desert may develop on the dry side.The mountains are said to produce a rain shadow.
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o In New Zealand, the Southern Alps along the West Coast intercept most of the moisture coming off the Tasman Sea, and as a result, the West Coast receives a lot of rain while the East Coast is extremely dry. This is like the rain shadow effect seen in the Sierra Nevada of California.
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that deserts often form on the continental side of mountain ranges, due to the rain shadow effect?