Narrator Listen to part of a lecture in a geography class. Now get

游客2024-01-04  28

问题     Narrator
    Listen to part of a lecture in a geography class.
    Now get ready to answer the questions. You may use your notes to help you answer. [br] What is the lecture mainly about?
Professor
    We’re gonna look at the effects of global warming on a particular country to get this thing into context and I want to look at Australia, a country with 12 000 kilometers of coastline. There’s a whole series of problems. What I mean by that is uh... in a country like this, well, there are floods, droughts, cyclones, bushfires, landslides, earthquakes, soil degradation and...so on—you name it, we’ve got it!
    OK. Now on your handouts there’s a list of reading materials which you should have a look at in preparation for your tutorials next week. I’d particularly recommend The Greenhouse Effect by Henderson-Sellers and Blong—they’re very good on the Australian situation. If you...for general background, Lovelocks is good, and the book edited by Pearman offers a nice review of greenhouse issues in Australia. I’ve put them in Special Reserve, so you shouldn’t have any trouble finding them.
    Okey...so I’m gonna start today by looking at one of the most serious effects of a change in the global temperature—that is, a rise in sea-level and...as I said, I’m gonna concentrate today on the effects this would have on the Australian context. If we assume that there’ll be a meter or so rise in sea-level over uh... say, the next fifty years—but unfortunately, the situation’s not so clear because we’ve got to take into consideration a variety of scenarios such as increased precipitation at the poles which might actually cause a fall in sea-level. Anyway, taking this figure of a meter rise over, say, the fifty or so years, what are we going to see? Well, we’ll see an effect on flooding of structures on the coast—you know, house, sea walls, ports and the whole infrastructure of roads, rails, power lines and cables, and so on.
    Secondly, we’re gonna be seeing shoreline retreat in some low-lying areas. The sea will move inland in areas...such as the Gulf of Carpentaria. To put it another way, in low-lying urban areas, your nice beachfront apartment may just end up floating away and your parking lot two hundred meters from the beach will end up as a prime waterfront estate. Most Australian cities are on the coast and in the case of Brisbane in particular—well, take a look at this overhead. That’s roughly the area indicated by the blue line that’s gonna be affected with a one meter rise in sea-level. So if you’re thinking of investing in real estate in this area, take my advice—don’t! Again, though, it’s difficult to predict the situation. Local conditions in some areas may actually increase the deposit of materials affecting an extension of the land. But whichever way you look at it there’ll be a fairly radical change to many eco-systems, and if you recall last week’s lecture on change—well, we’re really opening a can of worms here.
    Apart from coastal flooding, we should also expect the penetration of salt water systems into estuaries, rivers and lagoons. If you think about the Myall Lakes system for example—well, the whole freshwater complex could be reunited with the sea. One of the most serious direct consequences of this for man of course would be seepage into the groundwater—in other words, the sea’s salt water would enter the water table under the land. This would cause salinity in sources of drinking water and irrigation.
    Thirdly, we should expect to see a rise in temporary flooding of coastal areas. I’m not talking about flooding as a result of increased rainfall, though that’s another consideration I’ll come to it later. For now, I’m talking about flooding as a result of higher tides, Think about it, the swamping of the storm water drainage system. What’s that gonna do to the street you’re living in?
    So, in summary, as we’ve seen you’ve got coastal flooding, destruction of coastal structures, shoreline shifts and salt water intrusion. I’ll come back to some of these later, but for now, let’s move on and look at tropical cyclones. Everyone remembers Tracy. Or maybe you don’t because that is going back to 1974. I’m getting a bit old.

选项 A、Global warming.
B、Shoreline retreat.
C、Rise in sea-level.
D、Water intrusion.

答案 C

解析 本题为要点题,要求考生能够理解分散在听力材料中的关键词汇、词组和事实,并通过综合分析归纳出听力材料的要点。题目问:教授的演讲主要是关于什么主题?综合分析全文要点,可以总结出本文的主题为海平面升高这一地理现象。故选择C项。
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