Using geospatial data and high resolution aerial imagery from 2004-2010, USGS researchers documented spatially explicit patterns of disturbance, or land use, related to natural gas resource development, particularly disturbance patterns related to impoundments associated with hydraulic fracturing, well pads, roads and pipeline construction.

The study found that in Beaver County, two natural gas extraction sites resulted 5.5 hectares (13 acres) of disturbance, including 1.3 kilometers (.80 miles) of new roads. Disturbance in Beaver County is minimal and is narrowly distributed in the northeast corner of the county. This disturbance is attributable to Marcellus and non-Marcellus development.

In Butler County, 109 natural gas extraction sites resulted in more than 131.4 hectares of disturbance, including more than 20.8 kilometers (12.9 miles) of new roads. Disturbance in Butler County is concentrated in the lower two-thirds of the county. This disturbance is almost evenly related to Marcellus and non-Marcellus natural gas extraction.

Analysis of Lackawanna County data shows that the one Marcellus site developed between 2004 and 2010 resulted in five hectares of disturbance, including 0.5 kilometers (0.3 miles) of new roads.  Wayne County has five developed sites, with 16.2 hectares of disturbance, and 2.2 kilometers (1.37 miles) of new roads.  Neither Lackawanna nor Wayne counties were the location of substantial natural gas development.

Spatially explicit data on the level of landscape disturbance -- which is geographic information systems data, mapped to a high degree of spatial accuracy -- is critically important to the long-term study of the potential impacts of natural gas development on human and ecological health.

Through programs such as the National Land Cover Database, and Land Cover Trends, USGS has a long record of studying the consequences of land-use and land-cover changes. The current level of natural gas development in much of the country, and its effects on the landscape, is an important contemporary land-use/land-cover issue.

"Landscape disturbance can have a major impact on ecological resources and the services they provide.  This study examines the extent and pattern of the footprint of natural gas development on the landscape and provides a quantitative analysis of its relationship to the surrounding land cover," said Lesley Milheim, coauthor of the two studies.

Data from this report will be used to assess the effects of disturbance and land-cover change on wildlife, water quality, invasive species and socioeconomic impacts, among other investigations.

The studies, " Landscape consequences of natural gas extraction in Beaver and Butler Counties, Pennsylvania, 2004-2010," by, C.M. Roiga-Silva, E.T. Slonecker, L.E. Milheim, and A.R. Malizia, Open File Report 2013-1226; and  " Landscape Consequences of Natural Gas Extraction in Lackawanna and Wayne Counties, Pennsylvania, 2004-2010," by L.E. Milheim, E.T. Slonecker, C.M. Roig-Silva, and A.R. Malizia Open-File Report 2013-1227, are part of the series relating to natural gas landscape disturbance and they are available online.