1935 Ordinance Survey (OS) Map of Jerejak. Provided by Mike Gibby
If Kuala Lumpur is the capital of Malaysia, Penang would be food capital of the country. More so, the island state is well known for its historical heritage (now as World Heritage Site). In my previous blog post, we had a brief mention of George Town and its history.
I have developed another ArcGIS Online Web Template allows you to view multiple snapshots of history of Penang through the maps. I have sourced maps from the earliest days of Penang Settlement (started in 1786) by the British to the maps reflecting Japanese occupation of the Island.
Sungai Petani (1943) Courtesy of University of Texas libraries
On 31st August 2017, Malaya (now part of Malaysia) celebrated the 60th Independence Year. One of the best ways to see the changes of Malaya over the years is understanding the changes in town layouts.
Over the past few months, I have sourced multiple out of copyright maps, images and historical descriptions of selected cities across Malaya. I took this opportunity to look at selected towns (some of which are no longer prominent in the Malaysian scene) to relieve pre-Independence days of these settlements.
Unearth lost buildings, former railways and relieve memories of the past.
When time and online storage permits, I will look into adding other cities where I could source maps and relevant histories. I hope this map story application allows you to explore Malayan history through cities and more importantly, maps.
Please drop your comments of this application - both positive and constructive ones. If you want to see your town or settlement to be part of the application, please drop your name, city name and potential source for a historical map/images.
As Malaysia gears to GE14, we will be looking what are the key factors that are impacting voters' preference for the next elections. Watch this blog space grow with new maps over the coming months.
1) Plantation Scheme Issues
How does a plantation scheme across the country can have so much bearing on the next GE 14? Felda, world renowned program to raise the income of poor rural settlers, has been beset by lower commodity prices, financial mismanagement and questionable purchases.
If you look at the map above, Felda voters are largely located at the marginal seats of the ruling government. Assuming there is one-to-one fight between government and opposition, it only takes 22 seats to change the government of the day. With the introduction of GST in 2015, the effect kicked in on Felda Settlers. A good example was the Rompin By Elections of 2015. Comparing to 2013 and 2015 results of the same seat, ruling government winning margin substantially reduced.
With the fragmentation of the opposition (PR), the possibility of multi corner fight is high. Should that happen, Felda voters will be presented with multiple choices which allows the ruling government win the seat.
2) Challenging Existing Understanding the relation of Electoral Factors
Recently, with a collaboration of local Bosnian cartographer, Nurija, we have designed a map about landmine contamination in Bosnia Herzegovina. As Bosnia marks 25 years of independence this year, this timely map conveys the landmine legacy due to the civil war of 1990s.
As there are many mines (unexploded) still found in Bosnia, it continues to be a threat to anyone in the farm or during a flood time. If you want a map of a pressing topic, please contact me at the comment section and we can discuss further.
Recently, I was facing challenges in converting AUTOCAD Drawing files (.dwg) into useful shapefiles for both my work and (my own consultancy projects).
It is known that some organizations have GIS files for small scale sites while their engineering teams keep the large scale plans of the sites. Hence, there is an issue where the management is not able to see the big and the small picture of their assets.
Secondly, not everyone knows how to relate AUTOCAD plans to their daily life. They would like to see their site in a user friendly format (i.e. Google Maps, Google Earth).
Now we have looked at potentially scenarios, we need to ask ourselves what we should be prepared for when conversion of AUTOCAD to a GIS software (i.e. ArcMap). Below here are the things to be considered:
Is your file in dwg or dxf file format?
Do you know the projection of the AUTOCAD drawing is done?
Are you potentially aware that conversion will only bring spatial drawings (not the attributes)?
1. DWG or DXF Format?
.dwg file is native format for AUTOCAD. A .dxf file is interchangeable format of AUTOCAD product.
In ArcMap, one can freely add dwg file and all the layers (including attribute annotation) will come out. You can save them as a shapefile.
For QGIS, it will ONLY open a .dxf file. How can I convert .dwg to .dxf file? Refer to this article here for the procedure
2. Projection Issue
Everyone should realise one thing about conversion of AUTOCAD file to GIS file - there is no projection for the exported data. None at all!
How can I find the projection of AUTOCAD file. One is to open the dwg file on A360 Viewer. If you look at the survey plan, the mention of coordinate system or projections would be located at one of the corners of the plan.
If no (which I have encountered), please contact the source and obtain the projection name from the client or the surveyor.
Once we identified the name, we need to incorporate this projection to the GIS file. How?
QGIS
When you open the .dxf file or converted shapefile (adding vector), the system prompts you to add the coordinate system. Input the projection name and apply to all layers of AUTOCAD that is to be migrated into QGIS.
ArcGIS
In the case of ArcMap, the process is bit more complex. Bring the dxf file or converted shapefiles as unprojected files. Ignore all the error message. To ensure the shapefiles are to have the correct projection, we are going to do vector georeferencing. Vector georeferencing only works if the survey plan (AUTOCAD file viewed on A360) has coordinates marked on it or you find equivalent coordinates on another system.
To activate vector georeferencing, you must use Spatial Adjustment. When I was made aware of it by ESRI support, it worked wonders. Refer to the video below on how to use the tool.
3. Attributes?
While I do not have clear answers on this, it is important for you to be aware that conversion of AUTOCAD files to shapefiles WILL NOT BRING attributes (names, heights, feature types). If the file has limited attributes, one can manually add them as separate columns to the shapefiles (which I have done before).
However, if there are many attributes, I would like to hear your answers on bringing attributes effectively during the conversion.
Have you wondered how to do multivariable map of ethnic distribution? It has baffled me for a year or more as I was guessing on how atlases and magazines manage to produce highly detailed linguistic or ethnic maps of countries.
Ethnic Map of Chicago (Penn State University)
Recently, I just found the way to do so. In Malaysia, obtaining micro level data (at census collection district level or lowest level population divisible unit like U.S or Australia) is impossible. The closest lowest level demographic data I could obtain was electoral polling district level. It is not a complete representation on the ground but a very good sample set.
In this blog post, I will show you we can imitate those multivariable ethnic maps.
Excel Part
Obtain Excel data on population data of the region you want to explore
Watch this video below on key things you need to consider in ensuring your Excel data is ready for a join in ArcMap.
As you can see the above Excel example, each row represents a polling district level data (for this instance). However, in order to produce those ethnicity maps as shown above, we should only consider the Majority ethnicity for the polling district level
For this case, we should only consider percentage figures.
Once we determined the majority ethnic group per polling district level, we need to classify them of varying percentage brackets (i.e. 30%-50%, 50%-70%, Above 70%). Two additional columns are to be added.
Once completed, the second column with categorization is added. Using filters, group your data and label the data correctly.
Prior to exporting to ArcMap or QGIS, copy and paste values only all the figures. This will remove all formulas as GIS system will not accept them
Save the cleansed polling district data in a .csv format. Watch the following video for recap or clarification of the steps above.
ArcGIS part
In ArcMap, bring two datasets on the map using Add Data: .csv file of Population Figures and spatial data
It is absolutely important that the file format and value of Identifiers of two datasets are identical. I couldn't stress about this more because the attribute joins depends on commonality of the values and format
Right click the spatial dataset and choose Joins. Nominate the .csv file and choose the unique identifier. Run the Join
Ensure all the features are joined. Identify which ones fail and rectify them either in spatial or csv datasets
Once the Join is successful, go to Properties
In Properties, proceed to Symbology and choose categories. The field for Symbology visualization would be predominant ethnic group percentage classification.
Symbolize them with appropriate colour
Click Ok to apply the colour scheme
Check whether the desired map matches to your liking. Watch this video for recap or clarification of the steps above.
Gold, coltan, illegal mines, malaria, environment, money... So many things we can explain the Venezuelan Orinoco Mining Arc Project. Amidst of economic downturn, Venezuela opened up to massive transnational foreign investment for massive mining project. Venezuela is home to one of the biggest reserves of gold and coltan in the world (something we do not associate with Venezuela - home to world's largest reserves of oil)
This map I designed above documents the key things that would be affected by the Mining Project and also impact of artesanal mining (often illegal) in Orinoco region. While it is difficult to locate and place every possible impact of the project, these three maps will navigate you the context of the project
*I explicitly make it clear that I do not claim the ownership of any of the data needed for the map. The map is not for commercial use.
*Contact me here for any corrections or updates
Below here is the sources of the data (for the map)
