Sensitivity of hydrological variables in the Northeast Pond River watershed, Newfoundland, Canada, due to atmospheric change

Watershed runoff modelling techniques were developed and applied for assess ing climatic impacts, and tested for a watershed in the Northeast Pond Rive r basin using atmospheric-change scenarios from a series of hypothetical sc enarios. Results of this research strongly suggest that possible changes in temperature and precipitation caused by increases in atmospheric trace-gas concentrations could have major impacts on both the timing and magnitude o f runoff and soil moisture in important natural resources areas. Of particu lar importance are predicted patterns of summer soil-moisture drying that a re consistent across the entire range of tested scenarios. The decreases in summer soil moisture range from 10 to 50% for different scenarios. In addi tion, consistent changes were observed in the timing of runoff - specifical ly dramatic increases in winter runoff and decreases in summer runoff. Thes e hydrologic results raise the possibility of major environmental and socio -economic difficulties and they will have significant implications for futu re water-resource planning and management.