An isotope study of water bodies along a traverse of southwestern Canada


Link to Full Text

Download Full Text

Publication Date

January 1989


The 18O and D content of natural waters from southwestern Canada have been used in helping to characterize the regional hydrologic cycle. The isotope data correlate with four major physiographic systems; each one being readily identified by the gradient of δ-value with distance from the coast. In general, mountainous regions to the west exhibit negative gradients, whereas east of the Great Divide the slope is positive. Comparison of precipitation data from the Olympic Mountains and Vancouver Island with that of the Fraser Valley, indicate that vapour is modified by marine evaporation prior to passing over Vancouver. However, the isotopic composition of precipitation falling between Vancouver and the Great Divide can be interpreted tentatively in terms of a single-stage Rayleigh distillation process. Data east of the Great Divide that do not fall on the Rayleigh curve suggest either evapotranspiration effects or mixing of weather systems derived from other sources.

Document Type