Flooding is a natural component of riparian systems, however, changes in the extent, frequency and severity of flooding can impact forested systems. Persistent flooding and soil saturation can lead to tree mortality. Similarly, deterioration of river and stream banks from erosion can cause physical damage to riparian forests. As climate changes in the region, changes to the severity, extent and frequency may have negative impacts on a larger proportion of northeastern forests. We used the 12 years of data from the USGS historical instantaneous stream gauge data , categorized into severity categories delineated by the NOAA national weather service (flood, moderate flood and major flood).

Analysis

• Frequency
• Extent
• Severity
• Location

Disturbance Trend Summary

The data show a either a stable trend or slight decrease in the average number of days a station floods each year, the percent of stations reporting flooding and the maximum gauge height. However, these long-term trends are highly influenced by several large storms early in the data record.

Highlights

• Hurricane Irene (2011) was a heavy rain event that caused major flooding across the entire region. Years like 2011 indicate that even in inland areas, hurricanes can cause widespread and severe flooding across the region.
• Hurricane Sandy (2012) was not a significant flood event despite being a hurricane, indicating that extreme weather events such as hurricanes don't always result in high rainfall or flooding.
• In 2010 two different severe storms impacted the northeast. In 2014 a slow moving storm dumped record amounts of rainfall across New York, causing widespread and severe flooding. These events highlight that while hurricanes can cause widespread damage, frequent or slow moving storm systems can also cause major flooding.