已经是四月的尾巴，北京那边据说已经很热，过几天登山队一年一度的大腐败就要开始了，然后就是集训。五月份华北的阳光已经很毒辣，跑步爬楼之后每个人挂满汗珠的脸在这样的阳光下总是显得明晃晃的。
而小岛上的春天来得很晚。直到现在，气温也一直没达到20摄氏度。窗外的树上这几天才抽出了绿叶。跑步的时候还要带手套。今天乍暖还寒，天气有些阴冷，却又不下雨，搞得人也坐立不安。
所以不禁地，又开始想念北京夏天那种憋闷而又热烈的气氛了。
12号楼下的瓜摊，西瓜应该已经堆在地上供人挑选了吧？五道口的烧烤档，人声应该已经鼎沸起来了吧？西操的跑道，现在应该也开始散发它独特的塑胶气味了吧？
那种曾经让我无路可逃的闷热，如今却遍寻不着了。
前几天在日内瓦逛了一下午，倒是找回了一点炎夏的感觉。人行道上斑驳的树影，湖边吹来的凉风，恍如北京的后海，又像昆明的翠湖。这城市的居民真是好福气。可惜，独在异乡为异客，没法在那里多呆。夏天的感觉，现在倒成了奢侈。
2006年4月29日星期六
A minimum working MODFLOW simulation
Today one of my most important tasks is to establish a MODFLOW simulation that can work. Considering known figures, the simulation has to be very simple. I may only use BASIC module.
Now I am working with DISCRETION file, which contains information on the size and shape of the cell, as well as layer properties. The main problem so far is the DEM. The original file is too dense (with 0.1m resolution), thus I first extracted a part of data, with 100m resolution. The result is a data file much lighter. Though the rationale of such resolution choice still remain debetable.
From DEM I can get surface elevation needed by the model. However, the elevations of layers underneath are also needed. Thus I need to know the thickness of accotelm and catotelm. Different from my previous guess, the catotelm depth in different locations may vary quite significantly. For this period, I will set the catotelm depth to 2m according to Tallis (1973).
Mineral soil depth also varies. I used Reeve et al.'s (2000) simplication to set it to 0.5m.
I found a useful tool for parameterising the model: PMWIN 5.3. It provides a visual means to parameterise MODFLOW. As a simple model I just inputed the elevation of each layer. The hydroconductivities are left to default value. Gamble et al. (2003) gives transmissivity of 10 ft^2/d or 0.2 ft^2/d, using different methods. I choose 10 ft^2/d in this case. Peat porosity also seems to vary. I choose 0.85, which may need verification during fieldwork.
Now I am working with DISCRETION file, which contains information on the size and shape of the cell, as well as layer properties. The main problem so far is the DEM. The original file is too dense (with 0.1m resolution), thus I first extracted a part of data, with 100m resolution. The result is a data file much lighter. Though the rationale of such resolution choice still remain debetable.
From DEM I can get surface elevation needed by the model. However, the elevations of layers underneath are also needed. Thus I need to know the thickness of accotelm and catotelm. Different from my previous guess, the catotelm depth in different locations may vary quite significantly. For this period, I will set the catotelm depth to 2m according to Tallis (1973).
Mineral soil depth also varies. I used Reeve et al.'s (2000) simplication to set it to 0.5m.
I found a useful tool for parameterising the model: PMWIN 5.3. It provides a visual means to parameterise MODFLOW. As a simple model I just inputed the elevation of each layer. The hydroconductivities are left to default value. Gamble et al. (2003) gives transmissivity of 10 ft^2/d or 0.2 ft^2/d, using different methods. I choose 10 ft^2/d in this case. Peat porosity also seems to vary. I choose 0.85, which may need verification during fieldwork.
2006年4月28日星期五
新媒体时代？
这周 The Economist做了一个专题调查——新兴的“个人媒体”。560年前古腾堡发明的 moveable type带来了一个大众媒体时代，而今天，以 Moveable Type为代表的 blog以及其他新技术如wiki，podcast和 vlog等等，有可能改变人们获取信息的来源和方式，乃至信息内容本身，带来一个个人媒体时代。信息的来源从过去单一的，权威的传统媒体转变为多元的，互相补充、证明或证伪的媒体。人们获取的信息也从过去媒体精英代为选择、加工和过滤的内容转变为代表个人偏好的内容。
调查中列举了几种新兴的网络媒体形式：blog，wiki，podcast 并分别有专文研究。归纳一下，这几种媒体有一些共同的特点：home-brew，一般较小的受众范围，（除 podcast 外）即时的，互动的和不断进化的内容。互联网上内容的生产和消费，都在走一条 collective 的道路，不论是具有足够正确性和影响力的内容，还是个人过滤无用信息，寻求有用信息的努力，都比以往更多地依赖于集体的工作：无数次的删改、评论和搜索、阅读。The Economist 说，这也许代表了网络媒体的一种民主化倾向。
在这场变革当中，有几项关键技术是值得注意的，不完全列表：数据库，php，搜索，RSS 和 XML，以及 blog 软件。应该说，blog 的发布本身与上世纪90年代初个人主页的发布没有太大区别，但是为什么当年个人主页没有产生 blog 这样大的影响？我以为这是因为 blog 的简易和直接（几乎会打字就会使用）以及 RSS 和搜索技术带来的聚合 blog 内容的便利。
文章还分析了 Yahoo! 这样的“传统网络媒体”向“新兴网络媒体”转型的努力。而 Google 这样的公司，被看作是不生产内容的媒体公司——只负责媒体的组织。而 Second Life 这样的游戏（或者虚拟社区？）当中人们甚至可以拍摄虚拟人物的电影并在“现实世界”的网站上发布。第一个 blog 出现到现在大概还不到十年，这十年就带来了这样多观念的变革，不知道今后的十年中网络媒体又会怎样改变人们的生活乃至世界历史。
而传统媒体，目前看来正在试图在这个过程中找到适应之道。从现在的趋势看，能够认同并支持“草根媒体”的传统媒体仍然是许多 blog 的题材来源和人们获取信息的渠道，这部分媒体都向公众开放大部分内容，或者有专门的在线版本提供免费的信息，仍然不失其生命力；相反，那些需要交费订阅才能看到的传统媒体，在当今有失宠的势头。
调查中列举了几种新兴的网络媒体形式：blog，wiki，podcast 并分别有专文研究。归纳一下，这几种媒体有一些共同的特点：home-brew，一般较小的受众范围，（除 podcast 外）即时的，互动的和不断进化的内容。互联网上内容的生产和消费，都在走一条 collective 的道路，不论是具有足够正确性和影响力的内容，还是个人过滤无用信息，寻求有用信息的努力，都比以往更多地依赖于集体的工作：无数次的删改、评论和搜索、阅读。The Economist 说，这也许代表了网络媒体的一种民主化倾向。
在这场变革当中，有几项关键技术是值得注意的，不完全列表：数据库，php，搜索，RSS 和 XML，以及 blog 软件。应该说，blog 的发布本身与上世纪90年代初个人主页的发布没有太大区别，但是为什么当年个人主页没有产生 blog 这样大的影响？我以为这是因为 blog 的简易和直接（几乎会打字就会使用）以及 RSS 和搜索技术带来的聚合 blog 内容的便利。
文章还分析了 Yahoo! 这样的“传统网络媒体”向“新兴网络媒体”转型的努力。而 Google 这样的公司，被看作是不生产内容的媒体公司——只负责媒体的组织。而 Second Life 这样的游戏（或者虚拟社区？）当中人们甚至可以拍摄虚拟人物的电影并在“现实世界”的网站上发布。第一个 blog 出现到现在大概还不到十年，这十年就带来了这样多观念的变革，不知道今后的十年中网络媒体又会怎样改变人们的生活乃至世界历史。
而传统媒体，目前看来正在试图在这个过程中找到适应之道。从现在的趋势看，能够认同并支持“草根媒体”的传统媒体仍然是许多 blog 的题材来源和人们获取信息的渠道，这部分媒体都向公众开放大部分内容，或者有专门的在线版本提供免费的信息，仍然不失其生命力；相反，那些需要交费订阅才能看到的传统媒体，在当今有失宠的势头。
2006年4月27日星期四
万水千山
万水千山 [和讯博客]
当年在东操同一条跑道上你追我赶的人，也许真的在空间上会越隔越远了吧。但也许正是空间上的距离，才使得每一份心底的牵挂都更珍贵。不过，还是希望能够多有些相聚的日子。
去 Zermatt 徒步之后，我发现爬山的时候自己还是更喜欢 solo。大概还是不太会照顾别人，或者还缺乏一些责任感。不知道小变态怎么看，这次独自登雀儿山，感受得更多的是自由还是孤独？
远方的你们都平安，是我最大的心愿。
现在的生活足够简单，做饭好像也懒得研究菜谱了。不知道学成归国时XX烧牛肉这样的菜能不能达到八九级野球拳的水平，反正其他的菜式大约是暂时不会去研究了……因为 Sainsburys 卖的蔬菜性价比高的也就那么几种。
当年在东操同一条跑道上你追我赶的人，也许真的在空间上会越隔越远了吧。但也许正是空间上的距离，才使得每一份心底的牵挂都更珍贵。不过，还是希望能够多有些相聚的日子。
去 Zermatt 徒步之后，我发现爬山的时候自己还是更喜欢 solo。大概还是不太会照顾别人，或者还缺乏一些责任感。不知道小变态怎么看，这次独自登雀儿山，感受得更多的是自由还是孤独？
远方的你们都平安，是我最大的心愿。
现在的生活足够简单，做饭好像也懒得研究菜谱了。不知道学成归国时XX烧牛肉这样的菜能不能达到八九级野球拳的水平，反正其他的菜式大约是暂时不会去研究了……因为 Sainsburys 卖的蔬菜性价比高的也就那么几种。
2006年4月26日星期三
Why equity (must be addressed)?
A problem came up when I was reading a book about sustainable business. That is, why equity must be addressed when pursuing sustainability.
A quick answer is that failure to make resource and product equal to people will lead to social unrestness and ultimately threaten the existence of the business. But are there other reasons? What else should be allocated equally?
It was found in research that inequality can perpetuate poverty and hinder cooperation between groups of different social status. Inequality can lead to reduction of production (Daily and Ehrlich, 1996). Besides, economical inequality also impair the market as the demand will be curbed as less people have enough purchase power.
The equity between generations is itself a core implication of the sustainable development paradigm. For certain issues, the distribution of impact and distribution of efforts and responsibility also influence the incentives of various parties.
A quick answer is that failure to make resource and product equal to people will lead to social unrestness and ultimately threaten the existence of the business. But are there other reasons? What else should be allocated equally?
It was found in research that inequality can perpetuate poverty and hinder cooperation between groups of different social status. Inequality can lead to reduction of production (Daily and Ehrlich, 1996). Besides, economical inequality also impair the market as the demand will be curbed as less people have enough purchase power.
The equity between generations is itself a core implication of the sustainable development paradigm. For certain issues, the distribution of impact and distribution of efforts and responsibility also influence the incentives of various parties.
2006年4月25日星期二
“Chaotic\'’ processes in weathering
Today I attended a talk given by Prof. Alice Turkington from the University of Kentucky. The main idea of her speech is that in research on weathering, we should be aware of the delicate microclimate, biology and substrate characters in different locations of the surface and the implications of these differences in the weathering process. It is found that weathering demonstrates some chaotic behaviours, i.e. subtle difference of initial condition can lead to completely contrasting results after a period of weathering process.
Thus in weathering research one should address such chaotic processes, especially when the weathering is to be modelled and simulated using computer. She also mentioned some drawbacks of today's research method. A major problem is that laboratory conditions often bring variation of weathering process. After scaling down, the weathering process is different from real situation. Last but not least, weathering experiments often take years.
But I think, as the scope and scale of research is enlarged, the chaotic characteristic will gradually give way to more deterministic behaviours. While you cannot predict which side of a stone will be scratched more severely, you can to a large extent tell which side of a valley undergoes more significant wind effects. However, Prof. Turkington's speech reminds me that stochastic processes also play a part in erosion processes. To measure the rate of erosion may require understanding of the history of the landscape, vegetation and other changes. This, definitely, will make it more difficult to tell whether climate change significantly influenced erosion in Chilean coasts.
Thus in weathering research one should address such chaotic processes, especially when the weathering is to be modelled and simulated using computer. She also mentioned some drawbacks of today's research method. A major problem is that laboratory conditions often bring variation of weathering process. After scaling down, the weathering process is different from real situation. Last but not least, weathering experiments often take years.
But I think, as the scope and scale of research is enlarged, the chaotic characteristic will gradually give way to more deterministic behaviours. While you cannot predict which side of a stone will be scratched more severely, you can to a large extent tell which side of a valley undergoes more significant wind effects. However, Prof. Turkington's speech reminds me that stochastic processes also play a part in erosion processes. To measure the rate of erosion may require understanding of the history of the landscape, vegetation and other changes. This, definitely, will make it more difficult to tell whether climate change significantly influenced erosion in Chilean coasts.
2006年4月24日星期一
Evacuation Planning
Today I went into a seminar by mistake and did not leave in time. So I had to just sit through it. The speech was given by a professional from Devonshire County Council. He said he worked for Military Intelligence, which is a bit scaring. He discussed things to consider during incidents that require evacuation:
- Evacuate from what?
- Why evacuate? (Is there any alternative?)
- Evacuate who?
- When to evacuate?
- Evacuate to where?
- How to evacuate?
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