How drastically China's cities have grown over the last century

Over the past 30 years, China has grown from an agricultural-centric country to a largely urban society. Hundreds of millions of rural residents have left the countryside for larger cities, many in the hopes of finding better jobs.

Photographer Dheera Venkatraman spent a few years traveling around the country to create a series he called "Time Traveling in China". The project involved finding images from the 1900s and revisiting the locations they depicted, taking his own photos of what the landscape looks like today.

"Having studied physics before, I thought doing a trip in time, instead of space, might be an interesting thought," Venkatraman told.

Below, see 13 images of the drastic changes China's landscapes have undergone.

"To a local who has been around for decades and seen the old side of some of these photos, it might bring memories of those times," Venkatraman said.

"To a young cosmopolitan person, they might view these photos with curiosity and awe about what things really looked like before. To a futurist, it might invoke thoughts about what changes are yet to come in the next 30-40 years."

Venkatraman wants the images to convey different emotions for each viewer.

"There are many thoughts that can be taken away from these, positive, neutral, negative alike, and I'd like to leave that up to the reader to interpret," he said.

In 1978, no Chinese city had more than 10 million residents.

By 2010, six cities had 10 million residents, and 10 cities had between five and 10 million.

These Chinese cities are expected to have one billion residents by 2030.

China used more cement between 2011 and 2013 than the US did in an entire century.

This helped create the large cities and skylines you can see there today.

Many people in China live in high- or low-rise buildings made out of cement, unlike in the US, where most houses are made of wood.

China is home to some of the world's tallest skyscrapers and largest shopping malls.

Six of the 10 tallest skyscrapers set to open this year will be in China.

Venkatraman decided to photograph in black and white to create a more "apples-to-apples" comparison.

"I decided to flatten everything to black and white to eliminate all the distractions from insignificant objects — e.g. bright street signs, neon-colored rain jackets — and allow the viewer to focus on the more massive changes in buildings and cities," Venkatraman said.