|Intensification of subdivisions has more than doubled since the 1950's increasing from less than one third impervious area coverage to more than two thirds in the last 15 years.
|Most changes in rainfall intensity are mild trends, not statistically significant. Version 2.3 Engineering Climate Dataset.
Because flood damages are increasing, could it be the increased runoff due to intensified development contributes to flooding? Yes. The GIS analysis of a city in York Region up top shows how the percentage of impervious area has increased from the 1950's when less than one third of land was hardened with road, rooftops and driveways, to the early 2000's when over two thirds of land was hardened.
It is time to move past infographics (below) and consider real data when assessing flood risks and developing evidence-based flood mitigation policies in Canada:
|Sorry. We don't know what this means or what it is based on ... just that it is from the Ontario government and is a distraction to for any meaningful analysis or discussion on flood management.