Danny's research project for Mr. Harris was on telluric currents, but Mr. Harris told him that it bordered on pseudoscience and was not a suitable subject.
In Episode 3x07 - Currents, the gang takes Chris Argent's map and combines it with Danny's map of the telluric currents. The bodies are taken and sacrificed on intersecting points on the map.
Danny has marked the currents by color.
There are 3 orange lines that run North-South. Orange 1 runs along the eastern edge of the forest. Orange 2 runs parallel to the river between the river and the forest, and Orange 3 runs through the eastern, heavily populated part of town.
The Blue Line runs East and then South. It starts at the Beacon Hills Animal Clinic where it crosses Orange 2. The crosses Orange 3 at Beacon Hills First National.
The Red Line connects the bottom of Orange 1 to the river on the southern side of town.
The Green Line runs roughly parallel to Orange 3, but crosses over the river. It intersects with the Blue Line south of the Northern Bridge.