Category Archives: Open Source

Phnom Penh’s Land Area Increases 82%?

Source:  Mathieu Pellerin via Phnom Penh Mapping Meet Up

“Thanks to NEC’s Phnom Penh commune election result list, we  finally have the official communes forming Phnom Penh’s recently created 9th district, as well as the exact communes added to the other districts forming the edge of the capital. (red/pink = Meanchey; gray/green = Russei Keo; brown = Sen Sok; dark blue = Po Senchey; lime = Dangkao).”

Area based former Phnom Penh boundaries: 380.760 km2

Area based on latest Phnom Penh boundaries: 693.552 km2 


Boundaries as shown in the BAU Master Plan 2005.

Google Map vs Open Street Map – Phnom Penh

Comparison of Cambodia road files from OSM ( and GMM ( by Wil Waters, Richard Hintz, Mathieu Pellerin and Sovann Prey.

Open Street Map Shape Files

[   ] 06-Jun-2012 14:59 93K
[   ] amenities.tar.gz 06-Jun-2012 14:59 96K
[   ] cambodia.osm.pbf 06-Jun-2012 14:57 10M
[   ] 06-Jun-2012 14:54 7.6M
[   ] 06-Jun-2012 15:09 16K
[   ] places.tar.gz 06-Jun-2012 15:09 16K
[   ] pointsofinterest.gpx..> 06-Jun-2012 15:11 58K
[   ] pointsofinterest.kmz 06-Jun-2012 15:11 118K
[   ] 06-Jun-2012 15:08 4.5M
[   ] roads.tar.gz 06-Jun-2012 15:08 4.5M
[   ] 06-Jun-2012 15:09 1.1M
[   ] waterway_lines.tar.gz 06-Jun-2012 15:09 1.1M
[   ]> 06-Jun-2012 15:11 1.3M
[   ] waterway_polygons.ta..> 06-Jun-2012 15:11 1.3M

Land Portal Cambodia


The International Land Coalition (ILC) and are the originators of the Land Portal, an easy access, easy-to-use platform to share land related information, to monitor trends, and identify information gaps to promote effective and sustainable land governance. This partnership is open to other land-related organisations aimed to be actively engaged in the Land Portal development.


  We are shocked and devastated to learn of the killing of Chut Wutty, Director of environmental watchdog Natural Resource Protection Group (NPRG), in Cambodia today. Wutty was reportedly shot…
“Investment in large-scale plantations and concessions frequently increases food insecurity for the poor and violates their rights. This report documents how affected communities in Cambodia…
“Cambodia’s land-grabbing crisis has taken a disturbingly violent turn in the last two months, with at least five incidents involving armed forces opening fire during protests. A total of…
Final version of report including preface, introduction and 9 case study chapters. Based on presentations at Oct 2011 Translinks workshop hosted by LTC in UW Madison. Download the report: http…
“In their newly released article Borras and Franco detail the diversity of outcomes and arrangements falling under the blanket term ‘land grab,’ examining transfers of ownership and control of…
An article on women’s land rights by Mu Sochua – Cambodian MP and former Minister for Women’s Affairs – on the Cambodia Daily (January 10th 2012)
[From Trustlaw]  Nget Chhon, 71, was surprised, but not afraid, when anti-riot police punched her in the eye and beat her over the head during a protest against forced land evictions. “We…
1 December, 2011 The international meeting of South East Asian Regional Human Rights Commissions on ‘Human Rights and Business: Plural Legal Approaches to Conflict Resolution,…
1 December, 2011 The international meeting of South East Asian Regional Human Rights Commissions on ‘Human Rights and Business: Plural Legal Approaches to Conflict Resolution,…
1 December, 2011 Click here to read the BALI DECLARATION on Human Rights and Agribusiness in Southeast Asia Bali Declaration – English (0.3 MB) RELATED…

Phnom Penh Mapping Meet Up 5

PPMM5 presenter #1:

Tim Coulas, Cambodia Land Aministration Support Project

PPMM5 presenter #2:

Paul Gager, US bombing of Cambodia

PPMM5 presenter #3:

Den NhovUrban Voice Cambodia – an Ushahidi deployment for Phnom Penh


Phnom Penh Mapping Meetup Presentation

Phnom Penh Mapping Meetup. An updated version of the WHA Presentation.

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Open Source Mapping


During my thesis a friend of mine, Jeff Warren of Grassroots Mapping and the MIT Media Lab, introduced me to the concept of open source mapping. When my thesis site – Neft Dashlari (Oil Rocks) showed up on Google Earth only in name – he offered some tips on how to find other maps and posted them to the website. Another example: during the BP Gulf Oil Spill the group used grassroots mapping to map the extent of the oil spill – thereby offering an alternate narrative to the one told by the mainstream press.

Open Source Mapping Resources

Open Street Map is a project that engages the public in the project of developing digital map data comparable with Google maps.

GeoFabrik Web Site
Geofabrik was created out of the conviction that free geodata created by projects like OpenStreetMap will become increasingly attractive for commercial uses.

More Mapping Resources

Google Maps
Google Earth
Bing Maps
Digital Globe
Mango Map
USGS Seamless Data Viewer
USGS Earth Explorer 
The United Nations Environnment Progarm GIS Data Bank.

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GIS + Map Hunt Continued

Screen shot 2011-06-30 at 11.09.43 AM

I met yesterday with Paul Cote, the GSD GIS (Geographic Information Systems) guru – who has developed an amazing GIS Manual. The Harvard Library system also offers a very basic GIS tutorial and an introduction to GIS. GIS is new to me – until now I have mapped used Adobe Illustrator – which I think made a proper geographer like Paul cringe a bit.

According to Wikipedia: A geographic information system (GIS), geographical information system, or geospatial information system is a system designed to capture, store, manipulate, analyze, manage and present all types of geographically referenced data. In the simplest terms, GIS is the merging of cartography, statistical analysis and database technology. GIS may be used in archaeology, geography, cartography, remote sensing,land surveying, public utility management, natural resource management, precision agriculture, photogrammetry, urban planning, emergency management, environmental contamination, landscape architecture,navigation, aerial video and localized search engines.

Paul uses Arc GIS. ArcGIS is a Geographic Information System package developed by Environmental Systems Research Institute (ESRI). While a student license appears to be affordable it is only valid for one year – meaning if I went that route I  would have to upgrade to a professional license in a year which looks to be $3,000+. The alternative: Open Source GIS Viewers/Software

Online Mapping Resources

Maryland Global Land Cover Facility
The GLCF is a center for land cover science with a focus on research using remotely sensed satellite data and products to assess land cover change for local to global systems.

Historic Maps
The historical map collection has over 27,800 maps and images online.

Harvard Geospatial Library
The Harvard Geospatial Library offers search tools for finding geographic data, GIS data for download, and on-line geographic data exploration tools.

National Geographic Map Machine
This site facilitates full color mapping of world to street level geography. Users can also view and print historical and atlas maps, flags, facts, and even portions of Mars.

US Census Bureau American Fact Finder
Here users can produce basic thematic maps using 2000 US Census data. Users can also download the tabular information or map image.

Map Libraries
Earth Science and Map Library at the University of California at Berkeley Bodleian Library
Cornell Map Collection
University of Florida
James Ford Bell Library’s Historical Map Collection at the University of Minnesota
Library of Congress Map Collections
University of Minnesota Borchert Map Library
New York Public Library Map Division
University of Texas Map Collection

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Earth Shots

Campbell, Robert Wellman, ed. 1998. “Phnom Penh, Cambodia: 1973, 1985.” Earthshots: Satellite Images of Environmental Change. U.S. Geological Survey. This article was released 1 January 1998.


Phnom Penh, Cambodia
1973, 1985

From 1975 to 1978, Cambodia was ruled by the brutal Khmer Rouge regime, which sought among other things to build a vast system of irrigation canals. These images show an area around Cambodia’s capital city of Phnom Penh where such waterworks were built. Many areas east of the Mekong River, appearing tan in the 1973 image, show a half-kilometer gridwork in 1985.

(A note on terms: Phnom Penh is pronounced p-NOM PEN. Phnom means “hill” or “mountain” in Khmer; Penh is a woman’s name.1 More than 90% of Cambodians are ethnic Khmer, and Khmer is the national language.2 Cambodia has also been known as Kampuchea.)
The city at the rivers

Phnom Penh is just west of the four-way river intersection, which is called the Chattomukh (“Four Faces”). From the northwest and northeast, respectively, flow the Tonle Sab and Mekong Rivers. These waters merge and split into the Basak River and the Mekong, which flow southeast to the South China Sea.4

The Mekong River is the 12th longest in the world, flowing 2,600 mi from western China to the Mekong Delta in southern Vietnam.5 Every autumn, monsoon rains are too great for the Mekong to carry, and it floods a large area of Cambodia. This flood even reverses the flow of the Tonle Sab River, northward to the Tonle Sap (“Great Lake”) which can expand to ten times its normal size.6

This area receives 152 to 203 cm of rain annually, most of which falls during the southeast monsoons from mid-May to early October. Landsat images are effective for quantifying changes in surface water. While the images were both acquired after the monsoon season, the 1985 image clearly shows more surface water than the 1973 image.

Phnom Penh is the Mekong River’s largest city. Its population fluctuated wildly during the 1970s and 1980s; from an estimated 1.2 million in 1971 it swelled with war refugees to 2 million or more by 1975, when it was forcibly evacuated to almost nothing by the victorious Khmer Rouge communists.7 From 1978 (the last year of the Khmer Rouge regime) to 1987, Phnom Penh’s population grew from about 50,000 to 700,000. 8Because of the extreme instability in these decades, data on Cambodia are often fragmentary and contradictory.9
Khmer Rouge irrigation

From 1975 to 1978, Cambodia was governed by ideological pro-Chinese communists known as the Khmer Rouge (“Red Khmer”), who gained a reputation for extreme brutality. Even Pol Pot, the Khmer Rouge ruler, claimed that 10% of the population died (800,000 of 7-8 million), and other estimates were higher.11 Many of these deaths were from hunger, disease, war, and forced work, but there were also mass executions.

In their desire to radically transform Cambodia, the Khmer Rouge emulated both contemporary Communist China and the Khmer “golden age” of the 11th-13th centuries– both of which utilized irrigation. Canals around China’s Yangtze River delta harnessed rainy-season floodwaters, carrying them out to the surrounding lowlands where in the dry season people lifted the water up into their rice fields.12 Historical and archeological documents also indicate a local irrigation system in the twelfth-century Khmer state, possibly storing and distributing water so that rice could be grown year-round, two or more crops per year.13

The Khmer Rouge set out to build a system of canals, ditches and dikes. Citizens, including the evacuated city-dwellers, were forced to work in the countryside growing rice and building these irrigation works, with rigid work quotas and hard, slavelike conditions.14

There is disagreement whether this sacrifice and coercion even succeeded in irrigating Cambodia.15 Many projects were headed by loyal party leaders with no technical skills.16 Teachers, technicians, and other skilled (usually urban) professionals were hated by the Khmer Rouge as corrupting urban influences, and many were executed.17 There were reports of many ditches collapsing when it rained.18 It is likely that by the end of the Khmer Rouge regime, expertise had improved, but the post-Khmer Rouge government had to devote considerable resources to repairing irrigation works. One official said 80% of the projects had been poorly constructed, though it varied by region.19


These irrigation works are visible in the 1985 image, especially in the northeast quadrant of the zoom-in. Do you notice anything odd about them which could cause problems? (See one answer below.)

Satellite images

LM1135052007300390 (Landsat 1 MSS, 3 January 1973)

LM5126052008534890 (Landsat 5 MSS, 14 January 1985)

Defense Mapping Agency, 1973 (compiled 1968, revised 1973), Operational Navigation Chart K-10: edition 7, scale 1:1,000,000.

Answer to the Question Above

The ditches and canals are in straight lines, regularly spaced, at right angles. One might expect gravity-dependent canals to curve, like the creeks visible in the 1973 image. The Khmer Rouge built irrigation works along the 1-km gridlines of their military maps, ignoring hills, villages, and other topography. It is claimed that some canals actually did more harm than good, disrupting natural water supplies and encouraging erosion.20

It appears that each district had to dig a certain amount of ditches, whether needed or not.21 Workers had rigid daily quotas, so that some finished early and some could never finish.22 There were rigid decisions about which varieties of rice were acceptable, diminishing the diversity of varieties which had adapted to local conditions.23

Finally, the Khmer Rouge have been criticized for applying inappropriate models from the beginning. In emulating the Chinese system, for example, they ignored the amount of human labor needed to lift the water up to the fields. Where one square kilometer of Yangtze River lowlands may support 1500 laborers, the Mekong uplands may support only 300.24

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