Resilient stormwater infrastructure in Northern Virginia

The Northern Virginia Regional Commission (NVRC) partnered with Mason scientists to better understand regional vulnerability scenarios to flooding and runoff based on a comprehensive look at precipitation, population and land use/land change projections for the region. Data for past, current, and future projected rainfall patterns in the northern Virginia region will be integrated with population projections (and development plans, where available) to help inform future needs for and demands on stormwater infrastructure while considering climate change and regional growth. The goal is to create climate data for future conditions so that there can be an analysis of potential impact and risk to infrastructure and the need to invest in flood resilient landscapes.

Success of this project will be determined by the:

  1. Development of a hydrologic model that assesses effects on stormwater runoff from projected land-use changes and precipitation patterns, intensity and extremes for three watersheds in Northern Virginia;
  2. Development an adaptive framework/strategy for the application/replication of this model by local watershed planners and engineers (across Northern Virginia and the Commonwealth of Virginia).
  3. Recommendations for how the information can be used to create flood resilient landscapes and infrastructure

Key Findings

Significant increases in annual total precipitation were observed in the northeastern part of the southern mid-Atlantic U.S. Positive trends were particularly strong during summer months in the northeastern, central region of the domain. Our analysis of historical reanalysis precipitation records suggests that both the severity of extreme precipitation events at the daily scale, and their contribution to regional rainfall totals are growing. The historical record shows increasing intensity of short duration rainfall across much of the region, especially focused in the summer months.

  Left: Mid-Atlantic region (www.worldatlas.com/geography/mid-atlantic) with the study area outlined by a black box. Right: regional topography in terms of elevation above mean sea level; (B) North American Land Data Assimilation (NLDAS) annual mean precipitation from 1980 to 2018; and (C) boxplots of 39-year monthly precipitation distribution (1980–2018). In each box, the red line indicates the median, the box bottom and top edges indicate the 25th and 75th percentiles, respectively. The whiskers extend to the most extreme data points not considered outliers, and outliers are shown with plus marker symbols.

 

Spatial distribution of extremes and associated trends in extremes (1980–2018) for (A) average 1-day maximum annual precipitation with a histogram in the right corner showing the right skewed distribution of 1-day maximum precipitation for all grids; and (B) Theil-Sen 1-day maximum annual precipitation trend. The size of the cross markers shows the three significance levels used to perform a Mann-Kendall test on the Theil-Sen trends. Markers are not shown in grids with non-significant trends.

This project was part of the AGU's Thriving Earth Exchange program: https://thrivingearthexchange.org/project/northern-virginia-va/

Team: Corey Miles and Dale Medearis (Community Leaders), Celso Ferreira (CEIE), Paul Houser (GGS), Jim Kinter (AOES/COLA), Viviana Maggioni, Gustavo Coelho (Graduate Assistant), Ishrat Dollan (Graduate Assistant).