[1] Hydraulic fracturing has made vast quantities of natural gas from shale available, reshaping the energy landscape of the United States. Extracting shale gas, however, generates large, unavoidable volumes of wastewater, which to date lacks accurate quantification. For the Marcellus shale, by far the largest shale gas resource in the United States, we quantify gas and wastewater production using data from 2189 wells located throughout Pennsylvania. Contrary to current perceptions, Marcellus wells produce significantly less wastewater per unit gas recovered (approximately 35%) compared to conventional natural gas wells. Further, well operators classified only 32.3% of wastewater from Marcellus wells as flowback from hydraulic fracturing; most wastewater was classified as brine, generated over multiple years. Despite producing less wastewater per unit gas, developing the Marcellus shale has increased the total wastewater generated in the region by approximately 570% since 2004, overwhelming current wastewater disposal infrastructure capacity.

Surface coal mining is the dominant form of land cover change in Central Appalachia, yet the extent to which surface coal mine runoff is polluting regional rivers is currently unknown. We mapped surface mining from 1976 to 2005 for a 19,581 km(2) area of southern West Virginia and linked these maps with water quality and biological data for 223 streams. The extent of surface mining within catchments is highly correlated with the ionic strength and sulfate concentrations of receiving streams. Generalized additive models were used to estimate the amount of watershed mining, stream ionic strength, or sulfate concentrations beyond which biological impairment (based on state biocriteria) is likely. We find this threshold is reached once surface coal mines occupy >5.4% of their contributing watershed area, ionic strength exceeds 308 μS cm(-1), or sulfate concentrations exceed 50 mg L(-1). Significant losses of many intolerant macroinvertebrate taxa occur when as little as 2.2% of contributing catchments are mined. As of 2005, 5% of the land area of southern WV was converted to surface mines, 6% of regional streams were buried in valley fills, and 22% of the regional stream network length drained watersheds with >5.4% of their surface area converted to mines.

[1] Streamflow responds to changing climate patterns as well as human modifications within a basin. Understanding the contribution of these different drivers to changes in streamflow provides important information regarding how to effectively and efficiently address and anticipate changes in water availability. We used Budyko curves to ascribe changes in streamflow due to climate and human factors between two time periods in both natural and human-modified basins in the South Atlantic, USA. We extended the analysis to look at the consistency of climate and human alterations in 5 year increments within those time periods. Budyko curves were calculated for each watershed to describe the average climate control on a watershed given its land cover during the period 1934-1969. We then assessed how climate and human factors contributed to altering streamflow during the period 1970-2005. We found climate contributed to increased streamflow (average of 14%) in the South Atlantic since the 1970s. Human factors varied between basins and either amplified or minimized the effect of climate on streamflow. Human impacts were equivalent to, or greater than, climate impacts in 27% of our basins. The 5 year increments showed greater variability in climate, compared to human, contributions to streamflow change through time. Ordinations showed reservoir storage and population size negatively correlated with streamflow change, while the extent of agricultural land within basins positively correlated with streamflow change. Differentiating between the distinct effects that climate and human impacts have on streamflow is increasingly necessary for managing water resources under dynamic climate and human population scenarios.

Climate warming is likely to lead to complex effects on northern forests of the temperate forest biome.We investigated whether rising temperatures altered the timing of snowmelt and snowpack accumulation or extended the forest growing season length in the Turkey Lakes Watershed in Central Ontario. Archived satellite imagery was used to track changes in timing of snow pack loss/gain and canopy leaf on/off; the periods between these events were defined as the vernal (spring) and autumnal (fall) windows. We found only a slight extension of the growing season into the autumn period and no increase in the width of the vernal or autumnal windows, indicating that forest growth is not responding significantly to temperature increases during these windows. Archived time series of temperature, precipitation and discharge data for a nested set of catchments ranging in size from headwater (<10 ha) to regional (10 3 ha) catchments were used to track changes in the magnitude, timing and partitioning of precipitation into evapotranspiration and discharge. We found an intensification of hydrological cycling, with (1) a higher dryness index (PET/P) during the summer growing season, and (2) earlier spring snowmelt discharges and later more concentrated autumn storm discharges during the shoulder seasons.This intensification of the hydrological cycle during the summer growth season and the vernal and autumnal windows may not only limit opportunities for enhanced forest growth, but may be contributing to the recent observations of forest decline within this biome.