Have you ever faced severe weather like a hurricane or tornado? Recent research reveals that climate change is intensifying and increasing the frequency of such extreme weather occurrences, leading to significant damage to communities and infrastructure. To assess the most vulnerable regions, Canadian researchers delved into the environmental repercussions of a major flooding incident in southwestern British Columbia (BC) in November 2021.
Their focus was on a specific type of severe flooding known as a “deluge,” commonly seen on the Pacific coast of North America, caused by atmospheric rivers. These atmospheric rivers form when long clouds of water vapor move inland from the Pacific Ocean, triggering intense storms. In November 2021, an atmospheric river swept through southwestern BC, wreaking havoc by destroying local highways, pipelines, power lines, and railroads. Over 18,000 individuals were evacuated, and six lost their lives due to the floods.
The study highlighted that preceding the storm, British Columbia experienced severe drought and an unprecedented heatwave followed by widespread thunderstorm activities. In 2021, nearly 1,000 wildfires were ignited by lightning and human actions, marking it as the third-worst wildfire season recorded in BC. This was exacerbated by forests that had been logged or harvested, leading to slower regrowth and increased vulnerability to wildfires. The atmospheric river in November 2021 compounded the devastation caused by the wildfire season.
To analyze the impact of atmospheric rivers on southwestern British Columbia, researchers examined an area of approximately 70,000 square kilometers (27,027 square miles) through satellite images from Google Earth, Sentinel, and Landsat before and after the event. They detected alterations in river channels and geohazards such as landslides using satellite imagery and Canadian government data. Remote sensing technology like light detection and ranging (lidar) was employed to measure sediment redistribution by atmospheric rivers in the Coquihalla and Coldwater River valleys, revealing significant erosion.
The study revealed that geohazards on hillsides influenced sediment accumulation in rivers, particularly in areas with a history of deforestation and wildfires. Researchers identified over 1,300 geohazards along the Coquihalla River and the Coldwater River, with a significant portion located in regions affected by deforestation and wildfires. They attributed the severe impacts of atmospheric rivers to deforestation and wildfires, emphasizing the need for improved risk assessments to enhance community readiness for extreme weather events.
By shedding light on the long-lasting effects of unsustainable forestry practices, this study aims to aid in predicting and preparing for future severe weather events, particularly those involving atmospheric rivers. It underscores the importance of responsible land management to mitigate the adverse impacts of climate change-related extreme weather events.
Source: sciworthy.com
