Difference between revisions of "Assela Pathirana"

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''Average teachers become  good ones by  developing a strong passion for their act.  Some, then become excellent ones by learning to control this passion, so that students get more space to learn''.
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==Refresher Seminar on Asset Management==
[[image:oude_kerk_clock_delft.jpg|thumb|200px]]
We conduct a ten day refresher seminar on Asset Management of Urban Water Systems. It is open for the UNESCO-IHE Alumni outside Zambia. Fully paid scholarships available. Non-Alumni can also apply, but only as paid participants. [[refersh2011|Read More..]]


==Linux Has Arrived==  
==Urban adaptation in rapidly growing cities need a paradigm shift==
[[File:DSC00143.JPG|thumb|200px]]
[[File:kuznet_framework_for_scgs.png|thumb|500px]]
I have been using Linux for about twelve years. In the beginning, largely for specialized tasks, but later I found myself increasingly using Linux for day-to-day computing activities. Today, it has grown into a truly user-friendly, powerful, yet unassuming system that provides a very viable system for home,  office and educational computing. Especially the many features of today's Linux systems make them exceptionally well-suited for educational use. [[Linux_has_Arrived|Read More]]
We have been working with rapid developing cities like [https://en.wikipedia.org/wiki/C%E1%BA%A7n_Th%C6%A1 Can Tho], vietnam ([https://scholar.google.nl/scholar?as_q=can+tho&as_epq=&as_oq=&as_eq=&as_occt=any&as_sauthors=pathirana&as_publication=&as_ylo=&as_yhi=&hl=en&as_sdt=0%2C5 see our work]) regarding adaptation. Here we intentionally use the term "Urban Adaptation" instead of more common "[https://en.wikipedia.org/wiki/Climate_change_adaptation Climate Adaptation]". The reason for that is, in cities like Can Tho (or any other Secondary City in the Global South - SCGS), climate change -- while being extremely relevant and important -- is only one of many pressures that they have to deal with in adaptation; Land-cover change, rapid population increase, increasing pollution are some others.  


==Running [[:Category:WRF Model|WRF Model]] on Windows==
In these two part series, we argue the importance of changing the way we look at urban adaptation in SCGS. Simply put, we are in a context that is a combination of high urgency and high uncertainty. But, we still use 'predictive' planning approaches that works well only in contexts of good predictability and less uncertainty. While there are multiple reasons  (historical, cultural, economic) for this, it is important to start the discussion on how to change that to a more 'adaptive' -- or as we call it 'agile' approach. That is the story of these two articles. [[Urban_adaptation_in_rapidly_growing_cities_need_a_paradigm_shift|read more...]]
[[image:windows_fun.jpg|thumb|200px]]


[[:Category:WRF Model| WRF Model]] runs on [[:Category:Unix|UNIX]] platforms only. While this generally is not a problem for dedicated research or forecasting entities, for the casual user having access to only a Windows computer is faced with difficulties in trying out the modeling system. It is quite possible to install a UNIX-like operating system (e.g. Linux, BSD) alongside Windows, the technical details involved is enough to keep casual user from doing that.


With the introduction of a number of a number of [[wikipedia:Virtualization|Virtualization]] solutions by various entities another path has become open to try Linux tools on Windows. That is to use a [[wikipedia:Virtual_machine|Virtual_machine]] envornment that runs a Linux operating system within a virtual computer that is installed within windows. The beauty of the approach is the fact that the user does not have to be tech-savvy to use such a solution. Once a good setup is designed and implemented, it will run practically on any windows computer that is reasonably powerful. [[Linux_virtual_machine_with_WRF_installed|Read on for details ...]]
 
==The book on Climate Change, Extreme Rainfall and Urban Drainage==
[[File:igur_cc_rain_book.gif|thumb|400px]]
Some members of International Group on Urban Rainfall ([http://www.kuleuven.be/hydr/gurweb/index.html IGUR]) of  IWA/IAHR Joint Committee on Urban Drainage[http://www.jcud.org/] has produced a book on the topic on the influence on climate and other forms of future change on extreme rainfall and the implications on urban drainage systems.
 
In addition to a state-of-the-art overview of
existing methodologies and relevant results related to the
assessment of the climate change impacts on urban rainfall
extremes as well as on urban hydrology and hydraulics, it contains a number of tutorials on how to use the described techniques in practice. One example is an easy-to-use tutorial on how to use [Category:WRF_Model|WRF model] on personal computers. This is a similar to -- but very much improved (therefore easier to use) -- the framework described in the article "[[Running WRF Model on Windows]]". [[The book on Climate Change, Extreme Rainfall and Urban Drainage|read more...]]
 
==SWMM5-Python==
[[file:QT4Agg_Swmm5_python.png|300px|right|thumb]]
This is a python module for running SWMM5 model via python and extract results as python objects. [[SWMM5-Python|Read more..]]
 
==IMHEN Report on Climte Change in Vietnam==
(C) Institute of Meteorology, Hydrology and Environment (IMHEN), Vietnam.  
 
IMHEN conducted the project "Impact of climate change  on  water  resources  and  adaptation measures" sponsored by the Government of the Kingdom of Denmark  with the participation  of  consulting  experts  from  the Danish  Hydraulic  Institute  (DHI)  and  the participation of many Vietnamese agencies. [[Vietnam: Impact of climate change on water resources and adaptation measures|read more]]
 


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==Mirroring LAMP Website==
[[File:DSC00143.JPG|thumb|200px]]
This web site runs on [[wikipedia:Mediawiki|Mediawiki]] with MySQL backend (Read details here: [[Mediawiki for personal webs]]. This is the story of setting up automatic syncrhonisation between my development machine (DM) and the (cheap, no-frills) web hosting account.  [[Mirroring LAMP Website|Read More]]


==Cross Compiling C and Fortran==
==Urbanization not only heats up the cities, but could increase extreme rainfall==
[[File:TreeTrunk.jpg|thumb|150px]]
[[File:heat_maps.png|thumb|450px|Latent heat and sensible heat flux maps for Mumbai (Simulation)]]
Recently I had to mix two large models written in C and Fortran (95 standard) to build a single monolithic program. In theory cross compilation is easy -- in practice its far from it. Your run off the mill 'hello world' implemented in C and called from Fortran (or vice versa) is one thing, but marrying off two large programs (numerous code files in each) written in two languages is a whole different story. Following is an account of my experience: [[Cross Compiling C and Fortran|Read More]]
On 21 July 1999, Nerima-ku region of Tokyo received an unprecedented 111 mm of rainfall in one hour! Later studies lead to the conclusion that this heavy rainfall development was aided by urban heating due to the [[wikipedia:urban heat island|urban heat island]] effect of the Tokyo city.
 
With the cities in the world increasing in size at a phenomenal rate, the question whether larger urban footprints could enhance extreme rainfall is no longer solely an academic one. [[Urbanization not only heats up the cities, but could increase extreme rainfall.|Read more..]]
 
 
==Using Wiki in Higher-Education: Application in organizing research groups==
[[File:Wiki_in_edu_fig_2.png|thumb|400px|left|]]
 
This is a natural extension of the story of this web site. I started this web site in 2006 [[How this site works|hacking MediaWiki software]]. That was just before I moved from Japan to Netherlands and started working at UNESCO-IHE. From the end of 2006, I used the same contraption to support my research group at UNESCO-IHE (which consisted of five six masters students every year, myself and one or two other faculty members). The experiment completed its fifth year in 2011. I was thinking this is the time to document the experience when I came to know that [http://www.hydrol-earth-syst-sci.net/| Hydrology and Earth System Sciences Journal] is publishing  [http://www.hydrol-earth-syst-sci-discuss.net/special_issue72.html special issue on Hydrology education in a changing world]]. Recently the article finished the review cycle and was published in HESS. [[Using Wiki in Higher-Education: Application in organizing research groups|Read More ...]]
 
==Improving Drinking Water Quality without Compromising Long-term Safety==
 
Treating water with chlorine is a time-tested way of ensuring biological safety of drinking water. However, excessive chlorination creates chlorination by-products, that are known to cause long-term risk of cancer. We attempted to make a safe compromise.
 
We integrated EPANET2.0 (a steady-stage, demand-driven water distribution network model), a particle back-tracking algorithm (can trace the origin of water delivered at any demand point in the network), chlorine and disinfection by product model and a multi-objective optimization algorithm to enable computing the optimal water treatment, minimizing long-term chemical risk (represented as cancer treatment cost.) [[Improving Drinking Water Quality without Compromising Long-term Safety|Read more...]]
 
==EPANET-Python==
[[file:QT4Agg_Epanet_pressure.png|300px|right|thumb]]
When I started teaching programming for water professionals at UNESCO-IHE, I was compelled to use C/C++ as the language. This is due to the fact that EPANET2.0 and EPA-SWMM5.0 (Two main programes, students in my department had to learn) were written in C language. However, C/C++ is a horrible first language. Students have to cover at least three days of learning of arcane syntax and rules before they begin to write some semi-useful code. On the other hand, if I could conduct the classes in Python, they will see the `light' within a few hours! They can start doing interesting and useful things from the very beginning of the study. What a way to stimulate learning!


==Dependency Walker -- A remedy for distribution headaches==
I wanted to make it possible to call EPANET2 and EPA-SWMM5.0 procedures from python. Following is the first attempt: [[EPANET-Python|Read More...]]
[[File:2007-12-23 14.10.54 0000000270Tivoli-vialla andriana and Este 222.jpg|thumb|150px]]
If you have ever tried to give away a reasonably complicated program that was written and compiled on windows to another user you should be very familiar with complaints of missing [[wikipedia:Library_%28computing%29#Dynamic_linking|DLL]]s, and other dependencies and module mismatches etc., etc. These erros can manifest themselves in many forms (''The procedure entry point could not be located in the dynamic link library''; ''The application or DLL  is not a valid Windows image'' or even ''Program too big to fit in memory''.) This is particularly so if you happen to be developing with a complex build environment that is tightly integrated with windows system, like visual studio (I often use Visual C++ 2005/2008 express (free) editions and they create a lot of trouble in deployment!)
[[Dependency Walker -- A remedy for distribution headaches|read more...]]
===Remote Editing in UNIX===
Unlike Windows, UNIX computers were always meant to be accessed both locally (in front of the computer) and remotely (from somewhere remote). Even with today's high speed network communications, editing with a graphical editor like [[wikipedia:gedit|gedit]] over the network can be a tedious experience. You hit a button and wait ages for the user interface to be updated!. Of course if you are comfortable with vim or emacs editors which don't need any graphical interface, they you are fine. But for those who don't know these, there is [[wikipedia:WinSCP|WinSCP]]. [[Remote Editing in UNIX|Read more ...]]


==Ecosystem value of SuDS==
We analyse the implementation of  Sustainable Drainage Systems  (SuDS)  as a  solution to better
manage storm water runoffs and reduce urban flooding, and at the same time provide significant
Ecosystem Services (ES). ES vary from temperature control at urban and building scale to ma in water
savings, depending on the type of SuDS considered. [[Ecosystem benefits of SuDS|read more]]


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Revision as of 15:38, 1 September 2017


Random musings on various topics: Climate and water security, Small Island Developing States (SIDS), IT tools, Computer programming and Web-Applications, Citizen Science, ... Views are personal!

Urban adaptation in rapidly growing cities need a paradigm shift

Kuznet framework for scgs.png

We have been working with rapid developing cities like Can Tho, vietnam (see our work) regarding adaptation. Here we intentionally use the term "Urban Adaptation" instead of more common "Climate Adaptation". The reason for that is, in cities like Can Tho (or any other Secondary City in the Global South - SCGS), climate change -- while being extremely relevant and important -- is only one of many pressures that they have to deal with in adaptation; Land-cover change, rapid population increase, increasing pollution are some others.

In these two part series, we argue the importance of changing the way we look at urban adaptation in SCGS. Simply put, we are in a context that is a combination of high urgency and high uncertainty. But, we still use 'predictive' planning approaches that works well only in contexts of good predictability and less uncertainty. While there are multiple reasons (historical, cultural, economic) for this, it is important to start the discussion on how to change that to a more 'adaptive' -- or as we call it 'agile' approach. That is the story of these two articles. read more...


The book on Climate Change, Extreme Rainfall and Urban Drainage

Igur cc rain book.gif

Some members of International Group on Urban Rainfall (IGUR) of IWA/IAHR Joint Committee on Urban Drainage[1] has produced a book on the topic on the influence on climate and other forms of future change on extreme rainfall and the implications on urban drainage systems.

In addition to a state-of-the-art overview of existing methodologies and relevant results related to the assessment of the climate change impacts on urban rainfall extremes as well as on urban hydrology and hydraulics, it contains a number of tutorials on how to use the described techniques in practice. One example is an easy-to-use tutorial on how to use [Category:WRF_Model|WRF model] on personal computers. This is a similar to -- but very much improved (therefore easier to use) -- the framework described in the article "Running WRF Model on Windows". read more...

SWMM5-Python

QT4Agg Swmm5 python.png

This is a python module for running SWMM5 model via python and extract results as python objects. Read more..

IMHEN Report on Climte Change in Vietnam

(C) Institute of Meteorology, Hydrology and Environment (IMHEN), Vietnam.

IMHEN conducted the project "Impact of climate change on water resources and adaptation measures" sponsored by the Government of the Kingdom of Denmark with the participation of consulting experts from the Danish Hydraulic Institute (DHI) and the participation of many Vietnamese agencies. read more



Urbanization not only heats up the cities, but could increase extreme rainfall

Latent heat and sensible heat flux maps for Mumbai (Simulation)

On 21 July 1999, Nerima-ku region of Tokyo received an unprecedented 111 mm of rainfall in one hour! Later studies lead to the conclusion that this heavy rainfall development was aided by urban heating due to the urban heat island effect of the Tokyo city.

With the cities in the world increasing in size at a phenomenal rate, the question whether larger urban footprints could enhance extreme rainfall is no longer solely an academic one. Read more..


Using Wiki in Higher-Education: Application in organizing research groups

Wiki in edu fig 2.png

This is a natural extension of the story of this web site. I started this web site in 2006 hacking MediaWiki software. That was just before I moved from Japan to Netherlands and started working at UNESCO-IHE. From the end of 2006, I used the same contraption to support my research group at UNESCO-IHE (which consisted of five six masters students every year, myself and one or two other faculty members). The experiment completed its fifth year in 2011. I was thinking this is the time to document the experience when I came to know that Hydrology and Earth System Sciences Journal is publishing special issue on Hydrology education in a changing world]. Recently the article finished the review cycle and was published in HESS. Read More ...

Improving Drinking Water Quality without Compromising Long-term Safety

Treating water with chlorine is a time-tested way of ensuring biological safety of drinking water. However, excessive chlorination creates chlorination by-products, that are known to cause long-term risk of cancer. We attempted to make a safe compromise.

We integrated EPANET2.0 (a steady-stage, demand-driven water distribution network model), a particle back-tracking algorithm (can trace the origin of water delivered at any demand point in the network), chlorine and disinfection by product model and a multi-objective optimization algorithm to enable computing the optimal water treatment, minimizing long-term chemical risk (represented as cancer treatment cost.) Read more...

EPANET-Python

QT4Agg Epanet pressure.png

When I started teaching programming for water professionals at UNESCO-IHE, I was compelled to use C/C++ as the language. This is due to the fact that EPANET2.0 and EPA-SWMM5.0 (Two main programes, students in my department had to learn) were written in C language. However, C/C++ is a horrible first language. Students have to cover at least three days of learning of arcane syntax and rules before they begin to write some semi-useful code. On the other hand, if I could conduct the classes in Python, they will see the `light' within a few hours! They can start doing interesting and useful things from the very beginning of the study. What a way to stimulate learning!

I wanted to make it possible to call EPANET2 and EPA-SWMM5.0 procedures from python. Following is the first attempt: Read More...

Ecosystem value of SuDS

We analyse the implementation of Sustainable Drainage Systems (SuDS) as a solution to better manage storm water runoffs and reduce urban flooding, and at the same time provide significant Ecosystem Services (ES). ES vary from temperature control at urban and building scale to ma in water savings, depending on the type of SuDS considered. read more

SITES ON THE SERVER

[ Family web | Assela's web | Chandani's web | Medhini's web | Ayumie's web ]