Mapping for Whom?

Communities of Color and the Citizen Science Gap

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Mahmoudi, Dillon, Chris L. Hawn, Erica H. Henry, Deja J. Perkins, Caren B. Cooper, and Sacoby M. Wilson. 2022. “Mapping for Whom? Communities of Color and the Citizen Science Gap.” ACME: An International Journal for Critical Geographies 21 (4): 372–88. ACME open access link


In this paper, we examine the geography of the citizen science project Community Collaborative Rain, Hail and Snow Network (CoCoRaHS). This project is an important project because it is used to produce national rainfall data. Capturing rainfall data is also important because of increase in hyperlocalized precipitation events. Using a zero-inflated hurdle model, we find that the geography of the rain gauges are in primarily wealthier, white neighborhoods, leaving communities of color and low-income communities unrepresented in weather models.

Scholars have shown that communities of color and low-income communities are most vulnerable to the impacts of climate change, and without intervention, scientists will miss localized events in these neighborhoods and these communities might go unrepresented in rainfall models, further exacerbating the disproportionate impact.

This paper should be construed as a critique of the important work by CoCoRaHS and its volunteers. Instead, it should be a call for deliberate engagement of “missing geographies and people” in all participatory/citizen science projects. We argue social and natural geographies are co-constructed, and thus if we are measuring only part of a social geography, then the natural science we produce from that geography may only serve one part of society.


Citizen science harnesses the power of nonscientist observations, often resulting in a vast network of data. Such projects have potential to democratize science by involving the public. Yet participants are mostly white, affluent, and well-educated, participants that contribute data from their residence or places they frequent. The geography of the United States is heavily segregated along lines of race and class. Using a Census Tract-level hurdle model, we test the relationship between the locations of the rain gauges from the citizen science project Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS) with continuous variables for percent non-Hispanic white and median household income. We find whiter and more affluent Census Tracts are significantly more likely to have a rain gauge. The highly localized nature of precipitation combined with the uneven geography of storm-water infrastructure make data missing from citizen science projects like CoCoRaHS of vital importance to the project’s goals. We warn that scientific knowledge created from citizen science projects may produce scientific knowledge in service of wealthy, whiter communities at the expense of both communities of color and low-income communities.


Baltimore, Maryland and Portland, Oregon and the geography of tracts with rain guages.

One way to visually see the difference is by looking the geography of rain gauges with the percent BIPOC in Baltimore and Portland. On the left, Baltimore has numerous >80% BIPOC tracts with no rain gauges. The wings of the “black butterfly” are mostly unrepresented with the exception of rain gauges at large parks near the western city border. On the right, Portland’s inner eastside, where there is a cluster of tracts that are >80% white, are also well represented by rain gauges. Conversely, there are no tracts that are >80% BIPOC, but the 5 tracts that are 60%-80% BIPOC have no rain gauges. The areas that are 40-60%, especially outer east Portland, are not well represented. The paper has a more in-depth discussion and includes the hurdle model.