Xiaohua Wei
Earth and Environmental Science DepartmentUniversity of British Columbia

The relationship between forests and water has long been an important research subject since establishment of the first paired watersheds at the Wagon Wheel Gap in the USA in 1910’s. Numerous researches have been conducted to evaluate how forest changes affect hydrology or water resources using various methods (e.g., paired experimental watersheds, modeling). However, previous studies have mainly focused on small-sized watersheds (< 100km2), with much less on large ones (e.g., >1000 km2) (Wei and Zhang 2010).  It has been commonly understood that climatic variability and forest or land use change are two major drives for hydrological change.  To assess the impacts of forest or land use change on hydrology, climatic variability influence must be either included or removed. We have developed our own research methodology for separating relative contribution of climatic variability and forest disturbance to hydrological change over the past 5 years, and have applied this methodology on several large watersheds.  In this talk, I will summarize what we have learned in several case studies on large watersheds from the central interior of British Columbia, Canada. I will then discuss the possible implications of those research results for China.