Soils in this area are very pretty, and full of clay.

In spring of 2011, I decided to embark in a level of mastery of soil science. For someone like me with a short attention span, this was a massive undertaking, and I don’t regret one minute of it. I study sustainable infiltration of rainfall in soils in Wake County, NC in order to promote improved water quality and longevity in our drinking water.

The United States population is increasing 40 percent to 430 million people by the year 2050 (U.S. Bureau of the Census 2004). Over 70% of this population growth is expected to occur in one of 10 “Megaregions” throughout the nation, connected by proximity, economy, and infrastructure. The Southeastern Piedmont region is one of these megaregions. Projections show that by 2060, the area between Raleigh, NC and Atlanta, GA will be a connected megalopolis.   To deal with this influx of people, new roads and buildings need to be created to deal with stormwater runoff.  Soil is important in infiltrating rainwater.

Development changes how water infiltrates into the soil by adding surfaces that don’t allow water to infiltrate

Each soil has a certain maximum capacity to infiltrate rainwater and a steady state rate that is dependent on its physical characteristics. The Piedmont Atlantic Region has several unique soil characteristics that can exacerbate stormwater infiltration potential, mainly the large amount of clay in the subsurface soil. Understanding how water infiltrates, we can use what we know to locate water features and parking lots, and give us an idea of the size the parking lot can be so that its runoff can be infiltrated into soil, instead of into creeks.

The deeper you go into the soil, the less the slower water moves through it. These lower areas act like a concrete surface.

We think that the soil properties that occur in these lower horizons determine how much water can infiltrate, versus how much water runs off. To measure this, I am using historic data sources, hydrological modeling, and a laboratory column experiment.

This is a 50 cm tall and 25 cm wide column that we can use to measure moisture after I make it rain!