 Why you think IWA is positioning itself on the cities of the future? Yeah. So you know, the IWA Cities of the Future program started in the year of 2009. But I remembered four years before that in my own city here we held in IWA Congress. We used the IWA Cities of the Future. So why we decided to use that IWA? You know, my city is in the area suffering from water shortage. The modern water and waste water system was established more than one century ago as a result of industrial revolution. But at the time in this world we didn't have the problem of water resource shortage as well as some other resources and materials. So that's why for each city we have to supply sufficient water to the whole city for domestic industry and some other purposes. But nowadays things changed because the population increased to many folds comparing with one century ago. Now almost every city is facing the problem of water shortage and also shortage of other resources. Under such a condition we have to reconsider how to plan or construct our city. I'm happy after four years in IWA, the established the steering committee of Cities of the Future program and I was involved in this activity. IWA to establish this program is trying to solve the worldwide problems for urban development, especially for the sustainability of city development. We often hear the term urban metabolism, urban ecosystem. And it is something that I believe is central to this integrated city planning. Can you educate us a little bit on what this urban metabolism is? Okay, so actually urban metabolism, that idea was proposed in the 1920s by an American professor. So in his early paper he said a city is like a human body. For a human body in order to keep us healthy we have a very sophisticated or complicated system. So we take in air, we take in water, we take in food and everything we need. But inside our body we make use only the useful things but discharge the limited number of waste. For a city that's the same. And then the idea then is to limit how much resources we are taking on the outside environment and how much waste we are producing so that we are reusing things as much as possible within our urban ecosystem. Yeah, that's true. So if we say why in this world we have water? So that's due to what we say the natural hydrological cycle. So you say the water evaporates from the sea surface. It goes to the sky and then it condensed becomes a rainfall. So that's why fresh water can be distributed everywhere. And on the land the water flows through a surface runoff. So in that way every river, every lake, even underground aquifer we have water. The water finally discharged into the sea again. In such a way we can complete one hydrological cycle. My idea is such a cycle is only for the quantity of water but also for water quality. So you know evaporation is a process of disordination. We get fresh water and also on our earth surface there are so many processes. So in the river, in the lake there is a process we say self purification. We are learning from natural processes. Yes, yes. And including them in our urban planning. But with the development and industrialization unfortunately we depend more and more on engineering ways not to consider the function of the nature. So our idea is for the city in the future if we only say the water we have to consider how to combine a natural water system together with the engineering surface. And another topic you know not only for water reclamation because in the wastewater we have plenty of useful energy and the materials. Yes. How to recover these useful materials from wastewater is an important topic. My idea is for water, for materials, for energy that can be recovered from wastewater. It belongs to the concept of water metabolism. If I take my country as one example, the urban planner, they only consider how about the population increase. So how to build urban infrastructure, how to supply sufficient water, energy, other useful materials to the city. Okay? Yeah. We didn't put the idea of water metabolism into the design. Yes. Nowadays we have to design our city in a totally different way. We evaluate what's the total capacity for this area, how to control the expansion of the city, how to use the useful materials not only one time but to recycle it. So in many international conferences we discussed we have to create a new paradigm. The new paradigm is recycling, not only for water but also for all the useful energy materials. Materials. Yeah. So that's a very, very important topic. Working with that concept of urban metabolism in the further developments of our Cities of the Future program will be very fruitful. I believe for Cities of the Future program we have a goal, yeah, say maybe 10 years, 20 years. At that time all urban planners can work together with us. Okay? Yes. So we try to build a city so that's a really sustainable. So it's quite a limited resource input but we can use the limited resource to meet the demands for all people in the urban area. So I believe we will have a very splendid future. Very good. Thank you.