GIS and Migrant Deaths in the United States

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In recent years, migrant deaths in remote corridors across the US-Mexico border have become an increasingly important topic for both activists and government officials. Spatial analysis and GIS is being used in the study of migrant deaths to not only better track routes taken but also use results from research to limit deaths and danger to migrants.

Documenting Migrant Deaths with GIS

There are already sites dedicated to providing awareness on migrant deaths, in the hopes of preventing future deaths, and also acting as a source of closure for families missing loved ones and who have been identified as having perished while crossing the US-Mexico border into the United States. Pima County, in collaboration with Human Borders, has created a page dedicated to this endeavor.[1]  In Pima County alone, and since 2001, over 3000 migrant deaths have been documented and mapped.[2] 

Searchable map of migrant death locations in Pima County. SourceL Human Borders.

Research has highlighted a so-called funneling effect caused by increased surveillance along more urban routes in the US-Mexico border. As increased security has happened along previously common crossing points, more migrants are attempting to traverse remote areas along deserts to cross the border. This has resulted, as spatial modeling of metabolism in given terrain has suggested, the use of routes that are likely to necessitate more energy and physical stamina to successfully reach populated areas, which means that it is more likely to lead to death or serious physical problems for migrants as these routes lack water and other vital resources. To avoid these problems, one potential solution is to increase surveillance in desert areas or at least better anticipate where migrants might be funneled to so that aid agencies can provide resources in these areas.[3] 

Using GIS to Help Identify Deceased Migrants

While prevention of needless deaths is the ultimate goal, through increased awareness, efforts also are trying to match DNA samples of deceased so that identification can be made. In this case, spatial modeling using machine learning techniques can also be used to estimate a person’s likely point of origin. Simply identifying DNA may not be sufficient to identify where a deceased person may have come from; however, using DNA results along with other collected data, including where the person died and when the person may have left to migrate, could allow at least some close mapping to the likely start destination for the migrant.[4]

Spatial modeling that incorporates slope, vegetation, jaggedness, and temperature on the ground at given locations in the Sonoran desert indicates more difficult routes are being used, where results applied known areas migrants took based on locations where migrants died. This work has also demonstrate that while aid agencies and NGOs have in fact been aware that more difficult terrain is now being used, often times aid placed in the deserts for migrants is vandalized or even removed. Search and rescue, rather than strict enforcement of authorized entry, as well as aid in isolated areas being protected have been one set of recommendations based on spatial analysis comparison with policy.[5] To increase awareness, researchers have created an ArcGIS story map that documents migrant deaths in the Sonoran desert, showing also the history of legislation and increasing border surveillance as being causes in the increased number of deaths in isolated desert regions.[6]

Increasing dangers faced at the border between the US and Mexico have led to more deaths in the last decade. However, spatial analysis, including multivariate modeling, has demonstrated that how an increase in migrants deaths is in part the result of migrant avoiding routes previously taken by migrants due to increased surveillance. Increased monitoring of desert regions for distressed migrants could diminish migrant deaths; however, there is also controversy around this topic given some see the priority focus should be on stopping and detaining migrants, while others want increased aid. What spatial analysis has done is highlight the dangers faced by migrants and demonstrate the likely reasons as to why migrant deaths are increasing in remote regions.


[1]    For more on Pima County and its initiative to inform on migrant deaths, see: Arizona OpenGIS Initiative for Deceased Migrants


[2]    Map showing migrant deaths in Pima County:

[3]    For more on the funnel-effect of crossing the US-Mexico border as surveillance has increased in certain areas, including spatial modeling showing the need for more physical energy to successfully traverse the route to safer areas, see: Chambers, S. N., Boyce, G. A., Launius, S., & Dinsmore, A. (2019). Mortality, Surveillance and the Tertiary “Funnel Effect” on the U.S.-Mexico Border: A Geospatial Modeling of the Geography of Deterrence. Journal of Borderlands Studies, 1–26.

[4]    For more on using DNA and spatial modeling, along with machine learning, to determine origin of migrant who died, see:  Algee-Hewitt, B., Hughes, C., & Anderson, B. (2018). Temporal, Geographic and Identification Trends in Craniometric Estimates of Ancesty for Persons of Latin American Origin. Forensic Anthropology1(1), 4–17.

[5]    For more on recommendations for aid and spatial modeling demonstrating difficulties in terrain in the Sonoran desert, see:  Boyce, G. A., Chambers, S. N., & Launius, S. (2019). Bodily Inertia and the Weaponization of the Sonoran Desert in US Boundary Enforcement: A GIS Modeling of Migration Routes through Arizona’s Altar Valley. Journal on Migration and Human Security7(1), 23–35.

[6]    To the see the ArcGIS story map, see:



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