 I just went to Saigon, Ho Chi Minh City, and I'd like to show the progression of the city since 1815 until today, 2013. So that's 1815, you see there's a big fortress in the middle of Saigon. Well I guess the city was there before the fortress, regardless, so you see the city is really following the natural shape of the river and so on. In 1920, so the fortress has disappeared, you can see the garden. This is 1947. So it's much more detailed. This is 1975. This is 1975 with less detail. 2013, I'm interested especially in the south of the city, and the same year, and this is the satellite imagery. So the satellite imagery shows you a part of the city I'm specifically interested in. If we go back in time, so let's go back in time. So back in 1815, I'm talking about this specific stream of water. You can see it's depicted as a big river stream. In 1920, we don't have the map, but in 1847, it shows a network of rivers that seems to be quite developed here. Maybe I'm going to zoom in so you can see better what I'm talking about. This part here is supposed to be this network of streams. You can see that it's surrounded by rice paddies or floatable area. This is 1975. You can see that it still does exist. You can see it's a network of ponds, and you can see 1975 with less detail. So let's keep the more detailed version. In 2013, you can see that actually it has shrinks to be just one single stream, and you can see that some of the streams are now small streets. So what happened there? So let's have a look with more transparency. So here, so what were streams of river have now become streets. If I look at another more detailed picture, and this is another 2013 more detailed picture, what we can see is that the river has, I mean, the network of ponds have completely disappeared. And this is a more precise satellite imagery. So this is the big river, and that's the stream we are looking at. And all the network and subnetworks of ponds have entirely disappeared. So we've been on site and observed, and what we've heard from the residents was that 30 years ago, this network of ponds was clean enough to go and fish and wash your own body and drink the water of this stream, actually. And what we have seen today is a really dying pond that's extremely polluted, and basically the streams or the networks of rivers that have been transformed into a pile of garbage and oftentimes in tiny roads between very narrow passes between houses. So, yeah, so that's the observation we've made from the field in Saigon, in Ho Chi Minh, Vietnam, in 2013. Thank you very much for watching.