| Abstract/Description or Keywords |
In conjunction with available climate data, surface runoff is investigated at 12 gauges in the Quesnel watershed of British Columbia to develop its longterm (1926–2004) hydroclimatology. At Quesnel itself, annual mean values of air temperature, precipitation and runoff are 4Š6 °C, 517 and 648 mm, respectively. Climate data reveal increases in precipitation, no significant trend in mean annual air temperature, but an increasing trend in mean minimum temperatures that is greatest in winter. There is some evidence of decreases in winter snow depth. On the water year scale (October–September), a strong positive correlation is found between discharge and precipitation (r = 0Š70, p < 0Š01) and a weak negative correlation is found between precipitation and temperature (r = _0Š36, p < 0Š01). Long-term trends using the Mann-Kendall test indicate increasing annual discharge amounts that vary from 8 to 14% (12% for the Quesnel River, p = 0Š03), and also a tendency toward an earlier spring freshet. River runoff increases at a rate of 1Š26 mm yr_1 m_1 of elevation from west to east along the strong elevation gradient in the basin. Discharge, temperature and precipitation are correlated with the large-scale climate indices of the Pacific Decadal Oscillation (PDO) and El-Ni ųno Southern Oscillation (ENSO). hydroclimatology; snow; Quesnel River; river discharge; British Columbia |
