Earth Institute Research Projects

EAGER SitS: Signaling the Health Of Tree-pit Soil (SHOTS)

Lead PI: Professor Patricia J. Culligan , Ioannis Kymissis

Unit Affiliation: Columbia Engineering

October 2018 - September 2020
North America ; New York City, NY ; New York
Project Type: Research

DESCRIPTION: This EArly-concept Grant for Exploratory Research (EAGER) Signals in the Soil (SitS) award is a high risk/high return research project that could provide essential data for the modeling of rainwater infiltration in urban areas needed in the design and operation of green infrastructure for storm water management. As a result of high land surface coverage by buildings, pavement, parking lots, and other impervious surfaces, a typical city block generates five times as much stormwater runoff during wet-weather flow than a woodland area of the same size. This runoff, which contains pollutants including oils, heavy metals, particulates and nutrients, is responsible for the impairment of urban water bodies throughout the world. In the United States, stormwater runoff is the leading source of coastal zone pollution, and the third largest source of lake and inland water body pollution. Urban soils can soak up rain that falls within city boundaries, and thus help mitigate the adverse impacts of stormwater runoff. Nonetheless, the ability of urban soils to infiltrate rainwater is dependent on soil ecosystem health. Prior investigations into factors influencing urban soil ecosystem health have primarily involved manual sampling of soils followed by laboratory analysis. This has made it difficult to amass the number of observations needed, over both space and time, to fully understand the complexities of urban soil ecosystems. Without a better understanding of soil ecosystem behavior, it is difficult to develop strategies for managing urban soils in ways that maximize their capacity to reduce urban stormwater runoff. This project is an interdisciplinary collaboration between an expert in unconventional and advanced electronics (Kymissis) and an expert in geo-environmental engineering and urban sustainability (Culligan) to enable proof of concept for a wireless, low-power, in situ soil sensing system that has significant potential for soil ecosystem monitoring across a wide-range of settings. The new soil sensing system will be field-tested in urban soils located in New York City.

The in situ sensors comprise of miniature, low-powered, wireless sensors under development in the Kymissis lab. These low-cost systems use the circuit board as an integral mechanical element, and incorporate capacitance sensing for non-contact moisture monitoring, temperature monitoring, advanced power management, and Bluetooth wireless communication for relaying information back to a readout computer. The next generation system to be developed by this project will also add pH and dissolved oxygen (DO) measurements, enabling the sensors to measure indicators of the physical, chemical and biological health of soils. The sensing system will be used to monitor soils located in 40 urban tree pits within the Morningside Heights neighborhood of New York City. Culligan has prior, manually collected, data on relationships between the water infiltration capacity of these soils and tree pit design and management features. The data gathered from the sensors will be compared to this prior data to validate the performance of the new sensing system. Sensor data will also be used to advance understanding of the factors influencing urban soil ecosystem services. The research program is ideally suitable for involvement of local communities in citizen science activities which directly relate to stormwater management in their neighborhood.