Surface Tension — Reflections on Real Time Streamflow

This visualization maps streamflow data from the United States Geological Survey (USGS) in real time across the US.

Water supports life but can also drown and destroy. People are mostly water, but the melting ice caps threaten our very existence. Harnessing this elemental force requires a balancing act and this artwork is a reflection on humanity’s fraught relationship with freshwater.

Surface Tension can be viewed at
surface-tension.caitlinandmisha.com and on the video walls at Hunt Library.
Photo: Brent Brafford (NC State Libraries)

We created Surface Tension during an Immersive Scholar Residency at NC State which is focused on “the creation and sharing of digital scholarship in large-scale and immersive visualization environments.” We were psyched to create open source code and content for this project while working with publicly accessible (FAIR) data.

As an element that is constantly in a state of flux water is shared among people and this visualization is a response to how intrinsically linked we are to water and to each other via water. We decided to focus on fresh water, which people drink and interact with every day. Surface Tension uses the real-time streamflow data api from USGS which provides information for 11 thousand sites including gauge height, streamflow percentile, and several other columns. The movement (blobs) in Surface Tension are the data points for the percentile column for the date on which you are viewing it. All of the surface water on Earth is interconnected, and the disturbances at the specific points ripple out and interfere with each other, influencing each other and combining into an aggregate pattern of interdependence.

We used the open source javascript library D3, or Data Driven Documents, to work with 2d projections of the Earth and geolocate data points. The blobs on the map geographically correspond to USGS streamflow sensor stations.

A few notes on color choice: Water is often depicted as blue and beautiful, but we are really interested in our relationship to water and how we impact the water we need to live. Humans dump a huge amount of Nitrate into our waterways as agricultural runoff and as sewage (variously treated). This nutrient feeds algae, which can explode and consume the oxygen, suffocating fish and creating an unbearable odor. We used the color green to speak to algae as a sign of human presence, and blue to play with the so-called ‘blue baby’ syndrome resulting from excess nitrate exposure.

Our hand drawn map of rivers in the US is based on a map made by Walt Gurley using data from Natural Earth with line thickness weighted by scale rank (river size).

In addition to providing a reference point for the data the rivers simulate the movement of fluids both across the earth’s surface and in our own bodies.

Special thanks to NC State Libraries, the Immersive Scholar Residency, the Andrew W. Mellon Foundation and the USGS Raleigh.