In the fall of 2019, HARC completed the Forests and Floods project funded by the Texas A&M Forest Service. The goal was to compile and develop data to investigate the role that trees, forest, and canopy cover play in flood mitigation. 2018 Coastal Light Detection and Ranging (LiDAR) data, flown by Fugro Geospatial, Inc. was a principle data source to derive key datasets.
Datasets derived from LiDAR include forest canopy density and height, as well as a Hurricane Harvey flood inundation map. The research team at HARC used a variety of geospatial and analytics tools to perform data development, spatial analysis, and mapping production.
The Houston-Galveston region has undergone several extreme weather events in recent years including the May 2015 Memorial Day, April 2016 Tax Day, and the August 2017 Hurricane Harvey flood events resulting in loss of life and billions of dollars in damage to public and private property. The conversion of natural landscapes to impervious and developed surfaces alters watershed hydrology, resulting in increased peak flows, shorter lag time to peak flows and greater volumes of total runoff entering area waterways.
Recent findings indicate that: 1) watershed-based green infrastructure can decrease annual peak flow; 2) watersheds containing healthier green spaces are likely to generate lower amounts of runoff; and 3) a larger natural landscape area and preserved vegetation allows for infiltration and storage of stormwater likely reducing peak runoff. It is critical to understand the value of retaining forest canopy density and cover to reduce the volume of stormwater runoff and to mitigate peak flow during future flood events in the San Jacinto River Basin.
