【6】Groundwater is nonrenewable

Groundwater is the portion of the Earth's water cycle that flows underground. Groundwater originates from precipitation that percolates into the ground. The ocean is the natural sink for groundwater flows.

Unlike surface water, groundwater does not recycle readily. Rates of groundwater turnover vary from days to years, and from centuries to millennia, depending on aquifer location, type, depth, properties, and connectivity. The average time for the renewal of groundwater is 1,400 years . Shorter renewal times tend to be associated with shallow groundwater, while longer renewal times are associated with deep groundwater. Significantly, renewal rates of deep groundwater are about 1/15 of those of shallow groundwater. To some extend, the groundwater is practically nonrenewable; once used, they are not likely to recharge any time soon.

【5】A sustainable business

a sustainable business means a business that can thrive in the long term. Sustainability is bigger than a green product line, bigger even than a heartfelt but occasional nod to ongoing efforts to save the planet. Imagined and implemented fully, sustainability drives a bottom-line strategy to save costs, a top-line strategy to reach a new consumer base, and a talent strategy to get, keep, and develop creative employees. True sustainability has four equal components:

• social, to address conditions that affect us all, including poverty, violence, injustice, education, public health, and labor and human rights
• economic, to help people and businesses meet their economic needs—for people: securing food, water, shelter, and creature comforts; for businesses: turning a profit
• environmental, to protect and restore the Earth—for example, by controlling climate change, preserving natural resources, and preventing waste
• cultural, to protect and value the diversity through which communities manifest their identity and cultivate traditions across generations

【4】The compact city

The compact city is a concept related to urban planning and design which promotes for a high density city format in terms of residential land and other land uses. It is featured by mix land use patterns and efficient public transport system aiming at encouraging and supporting walking and cycling activities, which is relatively low energy consumption and more environmental friendly comparing with automobiles. In addition to the environmental considerations, the compact city is also known for its advocating in terms of social issues’ consideration such as social interaction and well-being and sense of the space with a feeling of safety as well.

The less-populated cities are likely to have more open areas within the urban landscape, where land is suitable for development. Filling up the urban gaps automatically increases city compactness. As population continues to grow, urban development has to take place beyond the existing city limited urban sprawl may harm the city’s compactness. Beijing, Shanghai, and Chongqing, three mega cities and municipalities, are good examples of “unlimited” urban sprawl without enhanced compactness. This fact is critically important because many local cities tend to follow the urban-growth models of Beijing and Shanghai in their urbanization processes. It is worth noting that China has experienced an increase in per-capita urban area in the past decade, indicating that land use has become less efficient over time and that there is a need for compact-city development in China. Expansion in urban living space and increase in city compactness both can help improve life quality in China. However, an acceleration in the compactness of China’s cities is needed in the future to ensure that land is used economically and sustainably.

【3】A smart city in China--Zhenjiang.

What is a smart city?

“Smart City” is a slippery term applied to everything from urban design to higher education policy. But the most accepted definition is the use of information technology to attack urban problems. Smart city systems are managing traffic, stabilizing electric grids, allocating and coordinating emergency services, and providing more city information to people and managers than has ever been available before.

Zhenjiang--A smart city in China

In this historic Yangtze River city near Suzhou, you can check the arrival time of the next bus, make an appointment at a city hospital, and find parking spaces or public bicycles—all from your smartphone.

Zhenjiang city buses continuously report their position and operating characteristics to a “smart dispatch” control center, helping operators improve scheduling efficiency and reducing fuel use and emissions. In a pilot project, some buses are now also sporting fast 4G wireless internet for riders. According to the city, half a million riders a day are checking bus arrival times using smartphone apps, and the city is saving 6,700 tons of carbon dioxide and ¥17 million ($2.7 million) in fuel costs per year.

For Chinese leaders, smart city technology looks like a win-win. For several decades, 20 million peasants a year have moved from the countryside to urban factories and construction sites, fueling China’s legendary economic rise. This immense migration is far from reaching an end:  China is currently only half urban, less than other mid-level developing countries such as Malaysia (73 percent urban) or developed nations like the United States (80 percent), and the Chinese government is counting on further urbanization to support economic development. What is now worrying Beijing is whether cities can support an additional 100 million residents. Pollution, housing affordability, and traffic congestion are already taking a heavy toll, so policy-makers are looking urgently for ways to let cities continue to offer migrants a better life. At the same time, economic planners are pushing hard to transform China from the world’s export factory to a self-sufficient modern service economy, and smart city technology looks like a good investment.