David M Wolock, Ph.D.

A series of projections of climate change were applied to a watershed model of the Delaware River basin to identify sources of uncertainty in predicting effects of climate change on drought in the basin as defined by New York City reservoir contents. The watershed model is a calibrated, monthly time-step water-balance model that incorporates the operation of reservoirs and diversion...

Topographic shape is a watershed attribute thought to influence the flow path followed by water as it traverses a catchment. Flow path, in turn, may affect the chemical composition of surface waters. Topography is quantified in the hydrological model TOPMODEL as the relative frequency distribution of the index ln(atanB), where a is the upslope area per unit contour that drains past a...

Various projection of climatic change were applied to watershed models of the Delaware River basin. Simulations indicate that a warming could reduce annual runoff by as much as 25 percent if current precipitation patterns continue. Simulations indicate that the largest changes in basin drought are in response to relatively small changes in precipitation. Basin drought was less sensitive...

The Thornthwaite moisture index is a useful indicator of the supply of water (precipitation) in an area relative to the demand for water under prevailing climatic conditions (potential evapotranspiration). This study examines the effects of changes in climate (temperature and precipitation) on the Thornthwaite moisture index in the conterminous United States. Estimates of changes in mean...

A new approach that uses weather-type analysis as a basis for stochastic precipitation modeling was developed and tested for Philadelphia, Pennsylvania. The weather types permit the identification of weather conditions associated with varying frequencies, intensities, and amounts of precipitation. Weather-type frequencies were used to stochastically simulate precipitation for...

This paper examines forecasts of changes in watershed runoff in the Delaware River basin that result from a range of predicted effects of increased atmospheric carbon dioxide (CO2) on future precipitation, temperature, and stomatal resistance of plants. A deterministic hydrologic model, TOPMODEL, was driven with stochastic inputs of temperature and precipitation to derive the forecasts...