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考古
A View Of Urban Sprawl From Outer Space Recent urban development in Los Angeles is less scattered than recent development in Boston. Miami is America's most compact big city and Pittsburgh is most sprawling. Changing the number or size of municipal governments in a metro area has no impact on whether or not urban development is scattered, but controlling access to groundwater does.
【控制地下水has impact on是否城市发展呈分散化】
These are among the startling findings from a University of Toronto-based team of researchers who used satellite data and aerial photography to create a grid of 8.7 billion data cells tracking the evolution of land use in the continental United States.
Matthew Turner and Diego Puga of the University of Toronto, Marcy Burchfield of the Neptis Foundation, a Toronto-based organization focused on urban and regional research, and Henry Overman of the London School of Economics present their findings in the May issue of The Quarterly Journal of Economics, in a paper entitled Causes of Sprawl: A Portrait（标本，模型） from Space. Heavily illustrated with Geographic Information System images, the paper challenges conventional wisdom about urban sprawl and presents a vivid and detailed picture of land consumption in America's cities.
【新研究出现】
Though urban sprawl is widely regarded as an important environmental and social problem, according to the authors, much of the debate over sprawl is based on speculation. The data to conduct detailed and systematic measurement of how and where land is converted to urban use has, until now, simply not been available. Despite widespread interest in the topic, "we know next to nothing （差不多没有）about the extent to which development is scattered or compact, and how this varies across space," they write. 【新研究的局限：based on speculation】
The authors merged high-altitude photos from 1976 with satellite images from 1992 (the most recent available) to create a grid of 8.7 billion 30-metre by 30-metre cells that tracks land use changes nationwide. "The data set we've constructed is unprecedented（空前的） in that we have coverage of the whole continental United States with a very high degree of accuracy for two time periods. That's never been done before," says Turner.【新研究的优势：覆盖面广，精确性accuracy】
The new high-resolution data allow the authors to observe the amount of open space in the neighborhood of every house in every U.S. city. Since development is more scattered when there is more open space around a house, the authors measured urban sprawl by calculating the average amount of open space in the neighborhood of a house in each city.【measure urban sprawl 的具体方法】
They found that more recent residential development is not any more（不再）
scattered than development was in 1976. Forty two per cent of land in the square kilometre surrounding the average residential development in 1976 was open space, compared with 43 per cent in 1992. "While a substantial amount of scattered residential development was built between 1976 and 1992, overall residential development did not become any more biased toward such sprawling areas."【结论一：scatter现象不再明显了】
The authors are quick to point out that any one household would have seen much change in the study period, but that "if we zoom out and look at the city from a distance, we see little change, at least in terms of the proportions of sprawling and compact development: the new city is just like an enlarged version of the old city."【结论二：虽然household 的变化大，但实际city的sprawling并不明显。】
Overall, Boston is less scattered than Atlanta, however recent development in Boston has been less compact than recent development in Atlanta. Miami, San Francisco and Los Angeles were the most compact major cities, while Pittsburgh and Atlanta were the most scattered.
The authors also investigated why some cities are more sprawling than others. They found that a city's climate, topography and access to groundwater account for 25 per cent of the nationwide variation. When the climate is temperate, people spread out to have more space to enjoy the weather.【研究城市之间sprawling的不同：1，适度气候导致人们spread out】
Hilly places see more scattered development as people avoid the costs of building on hillsides — but mountains act as a barrier and lead to more compact development. Places with easy access to groundwater see more scattered development, since people can supply remote houses with water by drilling inexpensive wells rather than paying for water lines. 【研究城市之间sprawling的不同：2，avoid cost of building on hill】
加亮部分有题：估计是推理题，问 mountain对scatter现象的作用有什么不同.这里把握住作者态度即可：hillside会导致scatter，mountain却反而 more compact. (因为山脉上没法建房子，人们只好集中在较为平坦的地方了，想想四川盆地。。而城市有hillside的就会往周边扩展，山上的房子造价太高～想想香港浅 水湾山上豪宅那个贵，所以只能填海了。。)
"The presence of aquifers（蓄水层） is particularly important," says Turner, "and that seems to me to have policy implications. It looks as if controlling access to groundwater is an important way to control whether development spreads or not."【照应文章第一段观点：控制地下水源决定了城市扩张程度】
Roads, on the other hand, have no impact on the extent to which development is scattered, despite commonly held beliefs to the contrary. "We looked at a lot of measures of road density — miles of road per area, average distance to a road, distance to an interstate exit — and we could find no relation between those measures and the scatteredness of development," Turner says.
The number of municipalities in a metropolitan area also does not affect development patterns. "You hear about fragmentation of jurisdictions being an important determinant of development patterns and we could find no evidence for that," says Turner. However, the team also found that development near cities is less scattered if it occurs in a municipality than if it occurs in an unincorporated area of a county. This suggests that people may be moving out to just beyond municipal boundaries in order to avoid more stringent municipal regulations.
【猜想1】：这里可以考municipalities影响cities to be not less scattered than unincorporated area的原因：avoid more stringent regulations.
【猜想2】：上面几个黑色短语可以考except题。
One of the common complaints about urban sprawl is that as development spreads, municipal services such as roads, sewers, police and fire protection are more expensive. The authors suggest that this concern is well founded. Development in municipalities that receive larger subsidies from higher levels of government is, on average, more scattered. Says Puga, "This suggests that as local taxpayers are held accountable（=responsible） for infrastructure costs, they respond by insisting on patterns of development that require less infrastructure spending."
"People have been eager to rush to policy prescriptions without a very good understanding of the underlying phenomena," says Turner. "We wanted to try to put the policy discussion on sounder footing."
。。。
如下考古版本来源是：http://forum.liuxuehome.com/showtopic-215844.aspx
85. aprilarchy 19号
阅读有一篇说city spawl 的原因，通过research检验传统的assumption.接下来三段一段说 climate被,证实，考了scatter development,后两段的都是
没有evidence 支持的。road,municiply,最后一段是说，随着发展，没被证实的原因也不是都不对的
还有一篇说的是一种科学仪器的发明弥补了原来的遗憾（考点），考了原文“tunnel“是指什么
第三篇说act法，限制中国的移民。以前historian所理解的影响范围太狭小,有题
86. duckfish 21号
1. 关于urban sprawl的（到现在还不知道是啥东东－，－），大体意思是说urban sprawl是一个社会问题也是个环境问题。有很多理论在争论引起
urban sprawl的原因到底是什么，一个小组勇敢的站了出来，开始收集相关的数据，以取得footing。他们首先发现climate是一个原因，in mild
climate, people tend to spread out. 还发现hill和mountain也是原因，hill是引起人们在hilly地方建造的成本，而mountain则是barrier，
帮助compact city（有道题目说hill和mountain起direct 作用，我觉得是错的）；还有地下水也有帮助，easy access to groundwater may help. （有题）
然而他们发现有些大家都认为的原因其实是没有作用的，一个是road，虽然他们收集了很多数据，但是没有证据表明road会影响；一个是法规的制约，
他们发现也没有什么用，但是解释说可能是由于人们倾向于住在城市边缘正好外面的地方，这样可以不受约束；然后他们发现有些common wisdom还是
有用的。然后提到说由于城市的建设需要纳税人的钱，所以纳税人更倾向于向一些基础设施比较便宜的地方发展。 |
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