Role of Urban Forests on Hydrological Cycle in Metro Vancouver

With increasing urbanization, more and more trees are removed from forested landscapes. Urban forests become more important as urban forests have many benefits mitigating air pollution, increasing oxygen and decreasing the heat island effect. Although there are many studies on the effect of urban forests on the hydrological cycle, the methods to implement urban forests in cities are lacking. The objective of this study was to analyze the effects of an urban forest on the hydrological cycle in Metro Vancouver and make recommendations on sustaining the urban forest to regulate the hydrological cycle.

A comparative analysis was conducted. The study site was Pacific Spirit Regional Park (PSRP) and its adjacent urban city (Vancouver) in Metro Vancouver. The study compared the effects of urban forests on the hydrological cycle encompassing PSRP with non-disturbed old-growth forests and PSRP with disturbed areas (second-growth forests and trails) to the adjacent urban residential areas of Vancouver in terms of runoff and evapotranspiration. The literature was used for the calculation of runoff and evapotranspiration.

Based on the results, several recommendations are suggested for implementing urban forests. First, it is important to maintain as much as old forests as possible. Second, it is beneficial to minimize the number of trails and roads. Third, everyone in cities needs to maintain as much green space as possible, and fourth, it is useful to plant trees in cities for future development. In conclusion, urban forests are important and should not be ignored in future urban developments.