Impact of climate variability and wetland drainage on watershed response in depression dominated landscapes

摘要

This study investigates changes in run-off production behaviour which may have occurred due to climate change/variability and/or as a result of draining of wetlands over Canadian portion of North American Prairies. The study uses statistical methods to quantify changes in precipitation/run-off over various spatial and temporal scales. The major results indicate dominated upward trends in some run-off metrics over some Prairie watersheds, whereas there is no concrete evidence of statistically significant precipitation trends during the observation period. The observed changes in run-off response, therefore, are interpreted to represent the possible effects of intensive wetland drainage. The remaining unchanged metrics over the majority of tested watersheds are interpreted to be due to varying progressive land use/cover disturbances which may have conflicting impacts on watershed response in the Prairies. The absence of significant changes in precipitation and observed changes in hydrology of some parts of the study area may support the narrative that loss of wetlands has led to increased flood risks in this area. However, information on major land cover indices like intact forests, agricultural land, urban areas within the study area, and landscape best management practices would be necessary to fully comprehend land use change and its impact on the Prairie's hydrology.