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Summer 2012 Blog - Casey Li

Casey Li is spending nine weeks at the Chinese University of Hong Kong.

August 3, 2012

casey_lunchFarewell lunch with my professor and his PhD students and staff

I can’t believe today is the very last day that I will be here in Hong Kong!  This will be my very last blog entry because I finally finished my 23 page report and my 12 Urban Climatic Maps on the probability of extreme heat events. This experience has really made me appreciate the importance of research in energy and inspired me to find ways in which I could use my civil engineering educational background to find ways in which a city could not only improve people’s living standards but also make it run more sustainably and efficiently. Throughout this internship I also learned a lot of the processes that go into conducting scientific research, especially with designing a methodology, taking account of all the different factors that could affect my results, and also better referencing skills for my papers. Moreover, I have become more independent in carrying out tasks as well as learning new software.  I am really thankful to have Professor Edward, Kevin and other people in the lab to help me whenever I have questions about my paper, my methodology or the ArcGIS software.

When reviewing my paper, Professor Edward told me that another professor in the department of public health, Professor William Goggins, was interested in using the data of the extreme heat events for each TPU of Hong Kong to find correlations between mortality data and the number of extreme heat events.  He is currently doing statistical analysis on the data to find out if there is a strong relationship between mortality data in each TPU and the probability of extreme heat events. If there is a strong correlation, my paper may also be published in a medical journal!  It is exciting to know that other people are using my research results in their work, particularly by scholars across another discipline.

Professor Edward and other people in the lab treated me out to a farewell lunch today.  We had Hong Kong Dim Sum at one of the campus restaurants and engaged in some interesting conversation. At first I was extremely nervous because Professor Edward asked me to go around the table and comment and evaluate on the character and work performance of each of the person sitting there and afterwards each one of them also evaluated me. I later realized that it was a light-hearted and spontaneous affair.  Nevertheless, it was nice hearing many positive evaluations from all the staff and PhD students whom I worked with.  I also later realized that Professor Edward is an extremely charismatic and funny person with a lot of interesting stories. I can tell that his students all greatly respect him.  I am definitely going to miss this internship experience and all the wonderful people I met!


July 18, 2012

Last week I finally got access to more HKO station data points, which mean that I can make my results more accurate but unfortunately I have to redesign my method.  I did more research on the different observatory stations to understand the effects of its location on the observed data.  For all its stations, the HKO tries to place their automatic observatory stations in environments where it is least affected by the UHI effect to gather the most representative of the ambient temperature.  This is probability the main reason why when calculating the probability of extreme heat events for each of the stations, it does not correlate with the probabilities determined by the UC Map classes for each station.  More research needed to be done on how the station condition and location is different from the averaged urban condition classified by the UC Map.

To help with this problem, I noticed that there were statistically significant differences between the rural and urban station temperatures especially in terms of its daytime warming rate and nighttime cooling rate after doing some statistical analysis. Thus I decided to classify stations according to their rural or urban characteristics: daytime heating rate and nighttime cooling rate. There were many ways I could of consolidating all the station data with the UC Map classes to find the probability of extreme heat events.  After careful thought and discussion with Kevin and Professor Edward, we finalized a method and I continued to create the four additional maps.  ArcGIS is an amazing software but unfortunately I found some limitations to the symbology tools when creating the maps. I want to be able to have a continuous scale for the probabilities and for the colour gradient to be consistent amongst the various maps so that people could visually compare and contrast the probability of extreme heat events in different areas of Hong Kong.  Unfortunately, this was not possible since the only gradient scale format separated it into discrete segments.  I have to think about how I could make the maps most understandable.  This is a very important part of displaying research because our main goal is to make whatever we discovered to be impactful and understandable for the masses.

My professor also suggested an additional project that I could take on where I need to create additional maps for each residential area and also Tertiary Planning Units (TPU) in Hong Kong.  This means I need to obtain the boundaries of the residential areas and TPUs and turn it into a raster file in ArcGIS.  Then using the boundaries, I must find the weighted average UC class and probability of extreme heat events for each residential area and again for each TPU.  This process made me really appreciate the statistical analysis functions of ArcGIS because of its intuitive toolbox and also it’s powerful computing functionalities for a large data set.


July 7, 2012

casey_fireworksJuly 1st Fireworks marking the 15th Anniversary of the Establishment of HKSAR

This internship has been an amazing educational and cultural experience for me so far.  During the weekends, I am able to fully experience HK, a place where the East truly meets the West.  I glad that I am fluent in both English and mandarin which makes it a lot easier for me to communicate with the locals and just get around in HK.  In many ways it is extremely Chinese with its street markets, food stalls, mini shrines placed in and outside buildings, and people talking as though they were arguing.  But in many other ways it is also very Western.  I was able to observe the 15th year Anniversary celebration and fireworks display, in honor and memory of the establishment of HKSAR.  I noticed how open HK is to freedom of speech and admired the struggles that HK faced in its attempt to form its own identity now that the Chinese reclaimed it from the British after 100 years of occupation.  I definitely noticed that there was more religious freedom and acceptance.  Most people have acquired a more western etiquette for behaving in public and while eating when compared to mainland Chinese people.   People will actually wait patiently in lines even when there are a lot of people around and in some Hong Kong restaurants you are given only forks and spoons as eating utensils.

The food here is amazing and has a lot of variety.  Other than its interesting mix of Mainland and South east Asian cuisine, HK food also has a lot of British influences.  In most restaurants you will be able to find a selection of Chinese and Western dishes.  They even follow the British by having afternoon tea sets which is a completely different menu from their breakfast, lunch and dinner sets.  A custom here that took me a while to get used to is that tables are shared so every single seat should be occupied at all times.  This means that if you and a friend are sitting at a 4 person table, two strangers may take the remaining two seats of the table.  It is even considered rude to place your bag on the empty seat next to you.  In some places, people will also be waiting right by your table for you to finish eating so that they will be able to take your seat afterwards.  This is understandable since any form of space in HK is extremely scarce and valuable.  Eating out is also extremely commonplace since most people’s homes are too small to invite friends over for meals.

The public transit system here is amazing and most people take the subway/train (called the MTR) to get around.  On average, the MTR comes every 3 minutes even during non-rush-hour times! Since HK is such a densely populated city, the MTR is constantly crowded with people shuffling shoulder to shoulder on the trains and the stations most of the time.  There is one Hong Kong etiquette that I keep on forgetting about and that is when you are standing on an escalator and have no intention to walk up it, you must stand to the right side of the escalator so that people who want to walk up and down can pass through the left.

The Chinese University of HK is located in what is called the New Territories which is considered more of the ‘rural’ areas of HK.  It is also built on hill kind of like if the Berkeley campus was built from the bottom of the hills to where Lawrence Berkeley Lab is located now.  Since I spend most of my time up in these hills, every time I go into the city the reality of the UHI effect in HK hits me as soon as I step out of the MTR (the HK subway/train system).  Even during the evenings, the air in the dense streets of HK can be extremely suffocating and uncomfortably hot.  I am definitely grateful that most buildings are well equipped with air-conditioning.  However, something that I really don’t understand is how cold the commercial buildings such as malls and restaurants put their AC on at.  Most HK people bring a sweater with them so that they can put it on when they enter into a building.  I find this kind of ridiculous, and I cringe when I think about the amount of energy wasted just for the unnecessary coolness.


June 30, 2012

It is such a sad coincidence that while I am in HK doing research on extreme heat events due to climate change, the United States have been experiencing one of its worst heat waves in history. When I look at news items regarding the US, I see so many articles with titles such as “Unrelenting Heatwave Bakes US: 30 dead”, “Deadly storm leaves millions without power in eastern US”, “Heat Wave wilts AC units”, “US wildfires are what global warming really looks like, scientists warn”.  I can’t help thinking about the socio-economic problems that heat waves can cause beyond what these headlines mention.   The heat waves definitely will disadvantage people of lower economic class since they will have financial constraints to access to AC and healthcare.  The droughts associated with heat waves can also create crop failures and increases in food prices, which will further disadvantage the poor.  The infrastructural damages can hinder transportation of people, goods, and services, which may hurt the economy in these areas.  Extreme heat events create far reaching socio-economic problems that needs to be addressed on many levels, in many different fields.

Reading about the amount of infrastructural damages and black outs it is clear that the nation is not well prepared for the effects of global warming.  As a civil and environmental engineering major, I think there needs to be more emphasis in creating high-performance buildings and sustainable transit systems to help out with the problems associated with climate change and also to better address our energy problems.  I strongly believe that this research project I am currently participating in will further help stimulate civil engineers and city planners in HK to have climate and energy concerns in their designs and projects.  This study identifies climatically sensitive areas which will help plan current and future development and planning proposals to make HK a greener and pleasant place to live.  Since I am doing research in the Architecture and Planning Department, I am also now more convinced that better urban planning decisions are needed to help reduced the consequences of global warming.


June 24, 2012

This past week I have finally finished writing a literature review on all the relevant topics and ideas regarding the impacts of the increasing numbers of hot days/nights and heat waves in Hong Kong.  My professor encouraged me to start writing up the methodology and begin the analysis.

The extreme heat events that I’m analysing are very hot days (VHD), very hot nights (VHN), hot spells during the day (HSD) and hot spells during the night (HSN).  The definition for these four events varies from country to country depending on their particular climate and the extent to which people and the built environment has adapted to it.  For Hong Kong, a VHD is when maximum daytime temperatures exceed 33 degree Celsius and a VHN is when minimum night-time temperatures exceed 28 degree Celsius.  Hot spells for day and nights are three consecutive days of VHD and VHN respectively.

The data I have access to currently is hourly climate data for the past 60 years from the Hong Kong Observatory (HKO) headquarter station.  My plan is to create a MATLAB function to isolate the summer months, the day time hours (10am-4pm) and night time hours (1am-6am), and search for the frequency of the various extreme heat events.

casey_workflowAn Illustration of Workflow for Creating the UC-AnMap (100m x 100m raster based)

Programming and sorting out large amount of data in MATLAB was not too difficult. My main challenge was figuring out how to make the map as accurate as possible with just one station data. First I had to thoroughly understand how the UC Map was created and the interaction of all the different layers. The raster map divides HK up into 100x100m cells and characterised each of them under one of eight different climatopes. These classifications were done by analysing the thermal load (from building volume, topography, green space data, etc.) and dynamic potential (from ground roughness, ground coverage, proximity to openness data, etc.) of each raster. Moreover, a relationship between the temperature variations between each of the eight classes has been verified through field measurements. This is great because I can use the equations developed to be a basis for my own map.  However, I need to take in to consideration that the temperature differences between classes are extreme cases and even so the field studies has a considerable margin for error.  I still need to find a way to validate my own data or at least further confirm the equations the study developed.

On the side, I have also doing some other work. Kevin (the PhD student I’m working with) has been downscaling different global climate models in order to predict future extreme heat events in HK.  I have been helping him by writing a MATLAB program to extract large amounts of data in netcdf format, isolate the data points to particular coordinates and time periods, and make it readable in excel.


June 16, 2012

casey_lab_arcGISIn the computer lab learning how to use ArcGIS

I am very excited to join this interdisciplinary research group of architects, urban planners, civil engineers and environmental scientists to investigate the problems of climate change in Hong Kong. This research group was commissioned by the Hong Kong Government in 2006 to develop “Urban Climatic Maps” (UC Maps) that identify the most sensitive areas to the effects of climate change. The UC Maps are influenced by those first created by the German researchers to help planners, politicians, architects, and engineers to make more informed and strategic decisions regarding city and building designs. The team has already used CFD simulations, wind tunnel tests, field studies and the integration of official planning and land-use data into GIS to produce a multi-layered (of over 50 different variables) map of the climatic conditions of Hong Kong.

My professor has entrusted me with conducting my own research to investigate the social, economic, and environmental impacts of the increase of extreme heat events due to the Urban Heat Island effect.  The UHI effect is when the average ambient temperature of cities is significantly higher than that of the surrounding rural areas.  The materials, location, and form of the built environment of the city absorb more radiation from the sun and are ineffective in releasing it, thus contributing to the temperature imbalance.  The UHI effect increases the number of hot days, hot nights and heat waves in Hong Kong which will have a lot of negative impacts on society.  Ultimately I would be contributing to the current UC Map by adding a layer on the probability of these extreme heat events in Hong Kong, accurate to 100 meters by 100 meters in resolution as well as writing an academic article on the methodology and findings of my research.

During the first few weeks I have been doing extensive reading on the UHI effect on countries with similar subtropical regions as Hong Kong. I have been examining current energy use in Hong Kong, especially on cooling and ventilation systems in buildings. I was shocked to discover that 30-60% of all electrical energy use in Hong Kong is for air conditioning and ventilation systems and the amount of energy use for AC is increasing due to the UHI effect. This has a significant environmental and economic impacts considering that nearly 80% of electrical energy in Hong Kong is produced from imported fossil fuels. I have also been looking at articles on the city’s infrastructure and the impacts of extreme heat and humidity. If temperatures become too high, there is a high chance for material failures due to thermal expansion in the city’s infrastructure which can disrupt transportation and economic activity. Engineers need to be aware of areas where the city’s buildings and infrastructure are more prone to increases in heat stress and find ways to mitigate these problems. But the most direct impact of UHI on regular people is its negative effects on human comfort and public health. There is much research done on the increase of heat related illness and mortality in Hong Kong and in other countries with similar conditions.

To get started, I began to write a literature review. It is my first time writing an academic paper but I am getting a lot of good help and suggestions from my professor and the PhD student who is overseeing my work. I have also been getting information on all the different types of data that I could use to determine the probabilities of extreme heat events and also finding out what other types of data I could present on my GIS map. Moreover, I have been playing around with the ArcMap software so I will be more familiar with it by the time I actually need to use it to develop the map layer.

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