Monthly Archives: September 2009

Mapping Massacres: GIS and State Terror in Guatemala

This is the title of a paper published in Geoforum in 2006 (PDF). Note that the paper was actually submitted in 2003 but the peer-review process appears to have taken 3 years. Ridiculous. I sympathize with the authors and hope they’ve turned to blogging. But the content of their paper is actually what I want to blog about here.

The authors use GIS to visually display the locations of massacres associated with Guatemala’s civil war at the department level and include information on indigenous populations as well as physical geography. They note that “maps have become tools of empowerment in Central America and elsewhere,” and highlight how indigenous groups “have begun to use maps as tools in their fight for land and marine resources, as well as greater political economy.”

It is worth understanding that “among some sectors of Guatemalan society, there is still wholesale denial and rejection of past violent events.” To this end, the purpose of “displaying exactly where violent acts took place is to [...] educate the Guatemalan public regarding the terrible violence of the recent past.” The authors suggest that “knowing the name of a specific town where a massacre took place is more concrete, potentially leading to perception of place and people, rather than simply being aware of violence in the countryside.”

Guatemala massacres

The authors produced the maps above, which clearly show that most massacres were concentrated in landscapes whose majority populations are indigenous. “Massacres were not random events in Guatemala. Instead, they took place in very specific cultural landscapes. “

The following short excerpts very much resonate with my thinking on crisis mapping:

“Even information that is easily comprehensible without maps takes on new meaning when it is portrayed spatially.”

“However, knowing in a general sense where the violence took place is not enough. If we fail to accurately display such information spatially, we fail to fully understand where and especially why these events took place. [...] By using some basic geographic information systems technologies, relationships between ethnicity, location, physical environment, and violence become much clearer.”

“Mapping these tragic events is critical because these maps also serve as another type of memorial for victims and their families. Many Guatemalans have yet to come to grips with the violence of the past. Maps, more so than words can help deconstruct violent events by providing a mental image of a location and event in the onlookers mind.”

The authors have certainly contributed a better spatial understanding of the violence thanks to this study. What is perhaps missing is an equally compelling temporal resolution so that events can be incrementally analyzed over time and space. Doing so may shed more light on the tactics and strategies employed to carry out the violence. These may produce specific patterns or a library of “fingerprints” that could then be used to investigate massacres in other countries.

Patrick Philippe Meier

Doctor Snow’s Health Map Propaganda

Doctor John Snow’s cholera map of 1854 is often heralded as an example of how mapping can illuminate powerful insights on otherwise hidden patterns. Not so, writes Mark Monmonier in his excellent book on “Spying with Maps” which I just reviewed here.

cholera-snow-map

Mark writes the following on John Snow’s famous map:

“If disease mapping has a poster child, it’s John Snow (1813-1858), the London anesthesiologist credited with discovering the water borne transmission of cholera. [...] Snow is best known for his 1854 map showing victims’ homes clustered around Soho’s infamous Broad Street Pump, which he identified as a source of contaminated water. According to epidemiological lore, the good doctor tried unsuccessfully to convince public officials to close down the pump.”

“Undaunted, he too matters in his own hands, removed the pump’s handle, and demonstrated the correctness of his theory when new cases plummeted. Truth be told, the epidemic had already run its course. What’s more, Snow made his famous dot map several months later, for a revised edition of his book on cholera transmission. Even so, his pin map continues to embellish discussions of GIS and disease.”

“Medical geographers, GIS experts, and some epidemiologists perpetuate the Snow myth because it promotes disease mapping as a discovery tool and enhances the stature of their own disciplines. But a careful examination of Snow’s writings indicates that he understood cholera’s mode of transmission well before he made the map.”

“Although Snow was a thoughtful observer, neither his map nor those of his rivals were of any value in generating insightful hypotheses. Snow’s famous cholera map was pure propaganda—and copycat propaganda at that—but proved eminently useful later in the century, when public officials needed convincing arguments to isolate drinking water from sewage.”

Although Mark is rightfully critical of Dr. John Snow’s legendary map, the last sentence above is quite insightful. The map, while unhelpful in knowledge discovery of cholera’s source, did become “eminently useful” to influence public health policy.

Patrick Philippe Meier

Doctor Snow’s Health Map Propaganda

Doctor John Snow’s cholera map of 1854 is often heralded as an example of how mapping can illuminate powerful insights on otherwise hidden patterns. Not so, writes Mark Monmonier in his excellent book on “Spying with Maps” which I just reviewed here.

cholera-snow-map

Mark writes the following on John Snow’s famous map:

“If disease mapping has a poster child, it’s John Snow (1813-1858), the London anesthesiologist credited with discovering the water borne transmission of cholera. [...] Snow is best known for his 1854 map showing victims’ homes clustered around Soho’s infamous Broad Street Pump, which he identified as a source of contaminated water. According to epidemiological lore, the good doctor tried unsuccessfully to convince public officials to close down the pump.”

“Undaunted, he too matters in his own hands, removed the pump’s handle, and demonstrated the correctness of his theory when new cases plummeted. Truth be told, the epidemic had already run its course. What’s more, Snow made his famous dot map several months later, for a revised edition of his book on cholera transmission. Even so, his pin map continues to embellish discussions of GIS and disease.”

“Medical geographers, GIS experts, and some epidemiologists perpetuate the Snow myth because it promotes disease mapping as a discovery tool and enhances the stature of their own disciplines. But a careful examination of Snow’s writings indicates that he understood cholera’s mode of transmission well before he made the map.”

“Although Snow was a thoughtful observer, neither his map nor those of his rivals were of any value in generating insightful hypotheses. Snow’s famous cholera map was pure propaganda—and copycat propaganda at that—but proved eminently useful later in the century, when public officials needed convincing arguments to isolate drinking water from sewage.”

Although Mark is rightfully critical of Dr. John Snow’s legendary map, the last sentence above is quite insightful. The map, while unhelpful in knowledge discovery of cholera’s source, did become “eminently useful” to influence public health policy.

Patrick Philippe Meier