Ending the reign of flooding

The model is able to identify potential locations of flood inundation, as well as the possible depth and volume of bodies of water.

Although the model can be seen as a universal tool in research into both mountain torrents and mudslides as well as urban flood scenarios, Hou spent most of his time and energy on the latter, with a focus on renovating old town areas where pipeline networks might be dated and in a state of disrepair.

He developed the model with his mentors during his studies at the Technical University of Berlin in Germany and Newcastle University in Britain.

On the basis of his predecessors' achievements, he made the simulation more stable and precise when analyzing complicated surfaces, and sped up the computation significantly using high-powered Graphic Processing Units.

After graduating in Britain in 2016, where he completed his postdoctoral studies, Hou came back home with a driving ambition, looking to seize the opportunity as China was galloping along the urbanization trail and seeking answers to questions raised by urban growth as cities expanded.

While Danish and British models have been widely applied in China for decades, Hou believes his model is competitive in providing better solutions.

Hou's model not only helps improve drainage capacity, but is also potentially able to contribute to risk awareness, traffic line optimization, and the maintenance of relative facilities. This is according to Ma Yue, assistant to the director of the Sponge City technology center of Fengxi New City at Xixian New Area, located between the cities of Xi'an and Xianyang, Shaanxi province.

The center, run by the local government, has provided Hou's team with high-precision topographic information and monitoring data about pipelines, outfalls of residential zones and other infrastructure that is needed to run the simulation.

Since 2014, the country has been exploring replicable ways to improve city capability of rainwater storage, seepage and purification.

A 2015 guidance released by the State Council points out that the measures aim to minimize the impact of construction programs on urban ecological environments.

The guidance announced a quantified goal that no less than 70 percent of rainfall should be consumed locally.

The 30 designated pilot Sponge Cities around the country include Guyuan and the Xixian New Area where rain gardens and green roofs have been built to control rainwater. The greenery is able to filter out pollutants, while the collected water can be used in cleaning roads and irrigating the city's green spaces.