State of stress in the conterminous United States

century drought in the conterminous United States

Droughts can be characterized by their severity, frequency and duration, and areal extent. Depth-area-duration analysis, widely used to characterize precipitation extremes, provides a basis for evaluation of drought severity when storm depth is replaced by an appropriate measure of drought severity. We used gridded precipitation and temperature data to force a physically-based macroscale hydrol...

Roadless space of the conterminous United States.

Roads encroaching into undeveloped areas generally degrade ecological and watershed conditions and simultaneously provide access to natural resources, land parcels for development, and recreation. A metric of roadless space is needed for monitoring the balance between these ecological costs and societal benefits. We introduce a metric, roadless volume (RV), which is derived from the calculated ...

Evapotranspiration Intensifies over the Conterminous United States

Using long-term (1948–1996) pan evaporation measurements, a 6% increase in warm-season (May–October) actual evapotranspiration (ET ) is computed over the conterminous United States between 1949 and 1996 via the complementary hypothesis. This predicted increase in ET is in agreement with the measured precipitation increase for the same period if long-term wet-surface ET is assumed to be constant...

Decline of forest interior conditions in the conterminous United States

Forest fragmentation threatens the sustainability of forest interior environments, thereby endangering subordinate ecological attributes and functions. We analyzed the spatial patterns of forest loss and gain for the conterminous United States from 2001 to 2006 to determine whether forest interior environments were maintained at five spatial scales. A 1.1% net loss of total forest area translat...

Nutrients in Groundwaters of the Conterminous United States, 1992-1995