编辑-地球科学江南体育网页版堆栈交换江南电子竞技平台

你不是登录。你的编辑将被放置在一个队列,直到同行评议。

我们欢迎编辑,使读者更容易理解和更有价值。因为社区成员审查编辑,请尽量使文章更好比你怎么发现,例如,通过修正语法或添加额外的资源和超链接。

牧师

为什么树打破在同一风速?

几个人都独立地向我提到树打破在同一风速。这种现象是独立的类型和大小的树。据说,伽利略已经描述这种现象之一他的书。我认为风速度是150公里/小时。我只是不明白是什么导致了这种行为是有效的对所有大小和类型的树木。

回答

一般要求似乎是不正确的:>这一现象是独立的类型和大小的树。基于其他的答案,在这个似乎声称树的规模并不重要。例如sciencemag.org文章中引用大卫Hammon的回答谈到实验在不同厚度的木头:>作为一个可能直觉,他们发现,固定长度,增加直径的棒强……这解释树大小等参数的关系树的直径和高度的大小往往并不重要。然而,这篇文章说什么关于木材的成分需要一个完全不同类型的实验。此外,主要观点是:>树,不管他们的直径,高度,或弹性,不会休息,直到风速达到42米/秒(94英里/小时)。请注意,这并不是说没有树木,可以容忍速度上面,没有折断,只是这是下界。这[美化网站][1]公司位于福罗里达州棕榈滩有一个广泛的树种和大风的宽容。它有一个长串的引用但经常提到这个研究:[风和树:一项调查的房主安德鲁飓风后)(http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=2708&Type=2)在这有许多确诊病例的树木幸存风速超过每小时94英里。有些记录幸存风速高达每小时150英里。 Note that while survival is different than having the trunk snapped, I think we can safely assume that if a tree survived, its trunk was not snapped. Unless someone can produce evidence that this university study was somehow flawed, I think we can pretty well say that different species of trees have different snapping tolerances for wind. It may be true that in temperate regions where high wind speeds are very rare that all trees can tolerate roughly the same speed and that the size of the tree doesn't really matter. But if you look to regions where hurricane-level winds are more common and the native plants that have adapted to those storms, this claim seems to fall apart in the face of evidence. Here are specific excerpts of the study mentioned above that explicitly contradict the claim that all species of trees have their trunks snapped by winds of 94MPH: > Trees along streets, in parks, in backyards were stripped of branches, uprooted or broken off by the **145 mph sustained winds** [emphasis mine] I think we can all agree that a sustained wind speed of 145MPH is not approximately 94MPH. It's not even remotely close. > Native Trees. Native tree species survived the hurricane better than exotics; chi-square analysis showed that 34% of exotic trees were still standing after the hurricane while 66% of native trees were standing (n21/1 p<0.0001) The paper also qualifies what standing/fallen means: > How Did Trees Fall? When trees fell, they were either uprooted, broken at he trunk or both (Table 2). From which I conclude 'standing' means 'not broken at the trunk'. This seems to be confirmed by following note about live oaks in particular: > Live oak was placed at the top of wind-resistance lists developed after hurricanes such as Camille (1969) and Frederick (1979) (1,6). Live oaks are well known to have exceedingly strong and resilient wood (1). In our study the few live oaks that failed we[r]e uprooted and **not broken at the stem.** [emphasis mine] It even calls into question the assertion that size is not a factor and notes this has been found in other studies: > Larger trees within a species were more likely to fall than samller trees. For example, the average height of fallen royal Palms was 15 m while the height of standing royal palms was 10 m. Fallen slash pines averaged 20 m high and 53 cm in diameter while standing pines were 17m and 45 cm. Few exceptions to this size failure relationship we[r]e live oak and pink trumpet. Other studies in forests have shown that three with larger diameters and heights were more likely to be damaged by hurricane winds Lastly the paper gives an hypothesis for why some trees can tolerated higher wind speeds: > Native dicots were more tolerant of high winds than exotics. This is not surprising since South Florida native trees have long been subjected to hurricanes, providing a natural selection for wind resistance. [1]: https://pamela-crawford.com/wind-tolerance-trees-palm-beach-landscape/

编辑总结

取消

\ begingroup美元树生存在树干厉声说。现在我可以看到一个窗口。一棵松树,一口就咬住了~ 20英尺的地面,树干在哪里~ 15英寸厚。大约20年前。上面的分支之一,成为新的树干,它以来,高度大约翻了一番。这并不罕见,至少针叶树(几乎所有自然生长在这一带)。我可以找到许多例子在当地山脉。树木,足够柔软的弯成一个圈从雪荷载(大概),那么从成长。 \ endgroup美元
- - - - - -jamesqf
2021年2月10日17:23
1

\ begingroup美元 @jamesqf我不怀疑你说的话,但我不认为这就是意味着在引用的研究。从我的阅读,而不是幸存的包括更广泛的损害,如失去太多的肢体。在一些例子中,槲被指出最小的损害在受到大风以及大约100英里。 \ endgroup美元
- - - - - -JimmyJames
2021年2月10日,在下午
1

\ begingroup美元 @jamesqf“远高于100英里”我的手指有时是愚蠢的。 \ endgroup美元
- - - - - -JimmyJames
2021年2月10日17:54

添加一个评论 |

正确的小错误或错误
澄清的意思,而不更改它
添加相关资源或链接
总是尊重作者的意图
不使用编辑与作者回复

创建代码用引号”或式子~篱笆
' ' '
像这样
' ' '
添加语言标识符来突出显示的代码
”“python
def函数(foo):
打印(foo)
' ' '
把段落之间的回报
在结束linebreak添加2个空间
_italic_或* *的* *
报价将>开始的
做链接(尽量使用https)
< https://example.com >
(例子)(https://example.com)
< a href = " https://example.com " > < / >示例
MathJax方程罪\ \ ^ 2θ美元

格式帮助»
回答帮助»

MathJax帮助»