Numerous and devastating floods in Texas cannot simply be written off as one more result of a changing global climate, a new study led by researchers at the University of Iowa shows. The blame, it argues, should be shared by human activities such as the construction of dams and other similar structures.
As one of the most flood-prone states in the nation, Texas was the only state to register flooding-related fatalities every year from 1960 through 2002. Still, few studies of Texas focus on the long-term changes in hazardous flooding, the researchers say.
"In this study, we examined the time series of the largest flood peaks every year from 62 stations in Texas with a record of at least 70 years," lead author Gabriele Villarini, assistant professor in the Department of Civil and Environmental Engineering and assistant research engineer at IIHR-Hydroscience and Engineering, said in a press release. "We were interested in examining whether flood magnitudes changed during the study period and, if so, what was the cause of these changes."
In doing so, he and his colleagues determined that the majority of these changes were somehow related to "human modification of the catchments and more specifically river regulation."
As evidence, Villarini notes that Texas has more than 7,100 permitted, some 2,000 of which were designed for flood control.
And nor did the study stop there.
"We also examined the link between flooding and tropical cyclones," Villarini explained. "Tropical cyclones are an important flood agent with regionally varying effects. However, they are not associated with the largest flood events to the same degree we found for the eastern United States."
Knowing this, while a step in the right direction, represents only the beginning.
"Despite the large economic and societal impacts of flooding, there are few studies focusing on changes in annual maximum flood peak distribution in Texas," he lamented. "This is particularly important because of the possible acceleration of the hydrological cycle associated with human-induced climate change, which could potentially result in an increase of floods."
Going forward, Villarini plans on studying the economic impact of flooding and tropical cyclones on the continental United States.