Title:مدیریت گسترش شهری: از نظارت جهانی تا سهام در زمین – شلومو آنجل

دکتر شلومو (سالی) آنجل، برنامه توسعه شهری NYU را رهبری می کند. مأموریت اصلی این برنامه کمک به شهرداری های شهرهای با رشد سریع در ایجاد فضا برای گسترش اجتناب ناپذیر آنها، ایجاد پیش بینی های واقع بینانه از نیازهای زمین در آینده و همچنین حداقل آمادگی های لازم برای سازگاری با رشد جمعیت آنها به طور منظم و منظم است. به شیوه ای پایدار، تضمین می کند که زمین فراوان و مقرون به صرفه باقی می ماند. ماموریت ثانویه برنامه توسعه شهری دانشگاه نیویورک، دستیابی به درک بهتری از گسترش شهری در سرتاسر جهان با نظارت بر آن در کل جهان از ۴۲۵۰ شهر و منطقه کلان شهری است که در سال ۲۰۱۰ دارای ۱۰۰۰۰۰ نفر یا بیشتر بودند و با جمع آوری و تجزیه و تحلیل شواهد. در مورد کمیت زمین مورد نیاز برای گسترش شهری، سازماندهی فیزیکی و مقرون به صرفه بودن آن، و نیروهای مؤثر بر آن در یک نمونه طبقه بندی شده جهانی از ۲۰۰ شهر از این شهرها.

قسمتي از متن فيلم: Thank you for having me Victoria and and the team I’m going to talk to the topic of my conversation today is managing urban expansion from global monitoring to stakes in the ground I’ll just give you a kind of brief introduction of how I got into it and I come from the study

Of Housing Policy and I’ve been studying it for a long time working in Asia and then in Latin America and I noticed that what happened to housing policy was that we when we started out we had two prongs of housing policy you know what do we do with the

Existing stocks the slums the squatter settlements how do we upgrade them give them tenure provide services and then what about the new stock what about all these new people who are going to come how are we going to house them so we started out talking about public housing

That didn’t get anywhere we moved to talking about sites and services maybe we just give them land and they build their own houses that also didn’t get anywhere and then people just gave up and forgot about it so when you ask people these days let’s say the World

Bank people are doing with how dealing with housing will find it’s all great about slum upgrading and infrastructure and so on but what about the new stock and then people say well I don’t know we forget about it so I got interested in the new stock so how do we make room for

The new stock so it turns out that for me the shift is instead of trying to make housing affordable we try to make land affordable make as long as land markets are open and affordable somehow the poor get land and they can house themselves so then the issue becomes how

Do we ensure the land remains affordable on the urban fringe so in order for Lanterman to remain affordable on the urban fringe we have to just see how much land is needed for expansion and how we can prepare that land and make it accessible so it can get integrated into metropolitan job markets

And so that my emphasis has changed to studying urban expansion and then when I come to a mayor and I say well your city is gonna grow up by two three four times during the next thirty years they say oh come on this is a joke that’s not never

Going to happen I said oh yeah it does happen and then I start to look at global numbers to prove that these things actually happen so unless you are an exception to the rule it’s what’s going to happen to you is what’s going to happen to everybody else and so let’s

Look at the numbers for global urban expansion so I basically stopped doing what I was doing and started to collect data on global urban expansion and this is how I got to this field so what I’m going to talk about is monitoring global expansion and then go back to talking

About mayors and what they’re doing on the ground in the cities that we are working with so we start out by saying and this appeals to people here who have a kind of a world world view let’s look at the universe of cities so what you

See here are all the cities in the world that have a hundred thousand people or more in 2010 and that number keeps changing we keep correcting it refining it right now we found about four thousand two hundred and forty five cities that had 100,000 people or more

And when I say cities I refer to cities a metropolitan area so I mean Chicago is the Chicago metropolitan area not the City of Chicago but includes everything around it so from that we move to monitoring so what we’re doing is first we’re mapping and measuring urban

Expansion and then and that was part of the answer to what I was trying to talk to Angelina and Roger when we were is the mapping and measurement of urban layouts which done at a different scale then and with different satellite imagery and to going to actually answer it answering

Some questions on the ground in the cities that we’re trying to get the information from so we have a partnership with with the UN habitat and the Lincoln Institute and the UN Population division to do all this work and much of it is done in preparation for habitat three in parallel to the

Work that you are doing so in order to work on the universe of cities obviously we need to sample so we sampled 200 cities out of this universe this is a very carefully selected sample much better than the early sample of 120 that we had because we got a lot more

Statistics professionals involved in creating this sample than before so it’s it’s a stratified sample it’s stratified by regions by city sizes therefore city size categories and by the number of cities in the country namely cities that countries that have only zero tonight at one to nine cities 10 to 20 and then 20

Or more got sampled in a slightly different way so the first thing that we do is we try to map urban expansion so we use satellite imagery to do that it’s like Landsat imagery 30 meter pixel size to look at impervious surfaces to define what’s built up not built up in water

And from that to construct maps of urban expansion what you see here is the urban expansion of Accra between 1991 2000 and 2014 you see that this is massive expansion and not something that any professional just telling you can you know how much do do we expect you see

There well I’d say 50 percent 75 25 but will not really give you real numbers what we find just to give you an idea is in the 24 years that we’ve been doing the measurements you know we’re doing 1990 2000 2014 that the built-up area of cities that we’ve measured has gone up

By a factor of two point two namely in the 24 years it has more than doubled right now when you say to people you know this is on every global average you know when you’re considering that in a lot of cities it’s really developing very little so the globally cities have

Expanded during the last twenty four years by 120 percent the expansion of Accra when you kind of want to go into the the inside story is the village chiefs on the periphery of Accra are subdividing and selling land to the middle class and the middle class is

Suburban izing because they can now own cars they can buy bungalows on the periphery and build housing so this is a very typical village Heath subdivision and and so it’s suburban izing just like New York was suburban izing at the turn of the century and this is a global

Phenomenon so when we’re talking about urban expansion it’s happening everywhere and it’s happening faster than the growth of population which I will explain so we just to check that urban expansion really is more rapid than population growth we look at 30 cities between 1800 and 2000 we did that

Of course not using air photographs because 1800 they didn’t really have satellite imagery we used maps of the built-up areas of cities and the cartographers in the old days did fantastic maps of cities that show their built-up area this for example is the we’ll tap area of Paris from the Atlas

Put together by a group in England called the Society for the diffusion of useful knowledge they put out a great atlas in there it’s SD UK you can still find those maps on eBay I collect them so this is the map of Paris in 1834 so

What do you see we we looked at maps of Paris at 20-year intervals to construct this composite map what you see 1800 is the area here during the time of Napoleon city of Paris is 11 square kilometres and has a half a million people in 2000 Paris has got ten million

People and 2,000 square kilometers so the population of Paris during that period grew from half a million to 10 million in good 20 fold the area of Paris grew 200 fault and the difference was that gradual the there was a density decline over this entire period of about

۱ ۱ and a half percent per year and that was enough for Paris to grow an area much faster than it grew in population when we look at these 30 cities this is just in passing we see that during the 20th century all the cities that we studied grew 16 fault

So between in on average between 1925 and 2000 all these 30 cities grow grew 16 fold for some cities let’s say Guatemala City between 1930 and 2000 or buenos aires between 1900 and 2000 Santiago Mexico City Mexico City between 1930 and 2000 grew up 16 times so it’s

Not uncommon for cities to grow up 16-fold right but when you talk to a mayor and you say well let’s talk about the next 30 years we’re talking about four fold six four it’s hard to convince the mayor if you don’t have these kind of if you don’t

Have these kind of maps in this kind of data and the reason that cities are growing faster in in area than in population is because density densities are declining densities are declining you know we don’t like densities to increase everybody who wants to talk about sustainability is saying we need

To increase density well that’s fine it’s wonderful but when we look at densities on the ground declining and they’re declining everywhere so between 1990 and 2000 densities in developing in declined at an average rate of 2.2% for the cities in the global sample and between 2000 2014 they declined at a

Much slower rate but still decline that their rates significantly different from zero and they declined we need to remember in all regions so the old literature said well you know the declining in the US but they’re not declining in Europe and they’re definitely increasing in developing countries that’s not true they’re

Declining very rapidly in developing countries and Europe and Japan are worried about sprawl that they weren’t worried about before and in the land rich developed countries the US Canada Australia they’re already very low but still declining though not significantly when you look at historically where the densities have been declining they’ve been declining

Very rapidly and when you look at 20 cities in the US for which we have data from 1910 you conceded it on average densities have declined fivefold between the beginning of the 20th century and the end of the 20th century so density decline is a very common is a very

Common thing of the cities in the global sample that we measured between 1990 and 2005 out of six cities had density declines between nineteen mm 2014 three out of four cities so it’s still a majority of cities have density decline okay so when we want our urban expansion

The thing that governs urban expansion and I was going to put a slide with a model but I didn’t put it in 50% of the variation in density is accounted for by city size and income namely largest cities are generally denser than smaller ones and richer cities are generally

Less dense than poorer ones and these to explain sixty percent of the variation in density so if there are policy issues they are at the margin and we’re trying to measure whether policy does affect density now having talked about density and expansion relative to population growth we’re asking ourselves well where

Is urban expansion going to take place in the coming 30 years and when we’re talking about planning for expansion to all the people that we’re talking about we’re talking about 30 years many of these mayors have 12 years plan 10 year plan it’s not enough to actually prepare

For expansion you want prayer for expansion we have talked about 30 years here we’re talking about where urban population growth is going to happen between now and 2050 and what we see and this is not the latest graph the latest graph is even more radical a quarter of

The increase in the urban population is going to be in sub-saharan Africa another quarter in the Indian subcontinent about 15 percent in China which is growing not so rapidly because the one-child policy and then the rest very small numbers in Middle East North Africa Southeast

Asia and so on in terms of the developed countries it’s interesting between now and 2050 the developed countries are going to add a hundred and thirty million people to their urban populations the developing countries are going to add eighteen times that so the growth urbanization is basically finished in the developed countries

Except in the United States with ninety millions out of these 130 millions are going to be in the u.s. the u.s. is the only developing country when it comes to population growth and urbanization all the other developed countries are not going to see any organization at all they’re gonna see shrinking cities so

That’s in terms of global picture of where organization is gonna take place now where urban expansion is gonna take place now urban expansion as I said some of it has nothing to do with population growth it has to just do with income growth you know you have more income you

Consume more land you consume more housing you consume more of everything so income growth is going to lead to some urban expansion so let’s say in developed countries from from a population perspective you’re not going to see any urban expansion but if income continues to grow if density is declined

By 1% per year the area of the cities in developed countries will double by 2050 they go up by two percent it’ll triple but and but when you talk about places where there are where there’s very rapid population growth like sub-saharan Africa if densities remain the same let’s say

There’s very little income growth it’s going to quadruple the cities are going to quadruple in size if there is income growth and density decline they can go up six times or even 12 times yes no I’d answer yeah it’s a negative the poorer the city the denser it is in fact

The elasticity of density with respect to income is about half namely if you double the income the density declines to have the less densities yes and the elasticity there is about 0.2 so if you double the size density increase by 20% yes yes we’re talking about the increase

In the built-up area of cities and the urbanized open space that is contained within this built-up area now the second phase of the research that we’re doing and then answer some of your julene are some of the questions that you were asking me is this expansion maybe it’s

Okay so so cities expanded wonderful so why do we have to worry about it if they expand and we are okay with the expansion let them expand right but if the question is what is the quality of this expansion and then so this second phase of our work has to do with looking

At high resolution imagery and seeing whether we can say something about the quality of that expansion so the what we’re looking is what and we can’t see with high resolution imagery as urban layouts so if you look at an urban layout let’s say even a suburban area a

Northeast in Northeast Bangkok what you see is the total absence of arterial roads for example which are essential in terms of the connectivity of metropolitan job markets people have to get to work they have to get to work over long distances so if you don’t have an

Arterial road in Bangkok in this area arterial roads are eight kilometers apart so that if you’ve been there and I’m sure some of you have been this one of the most congested cities in the world you just sit in traffic basically you’re not moving anyway so you take

Another example the counter example this is an invasion on the outskirts of Lima it’s a squatter settlement but it was an organized squatter settlement they are usually organized by Jesuit priests and these priests got the students from the engineering department of San Marcos University and Lima to go and survey the

Land before they invaded so it public land they so they divided it into blocks with plots of ten meters by 20 meters then people came in do at night they build a shack in the middle bamboo Shack in the middle of that plot then they start to dig a trench about

Half a meter wide around the entire plot this is my plot and then gradually they built walls around that around that plot and rooms inside so this became very quickly a kind of integrated into Lima suburbs these are all very nice houses that are selling between thirty and forty thousand dollars apiece they’ve

Been granted tenure during the fujimori time they were big land tenure granting programs and this is totally integrating the city these surveyors left ten meters of road between between blocks so it is a plenty of room for movement plenty of room for parking and 25% of the land is allocated

To streets here so the way that we measure these urban layouts we can no longer look at the entire metropolitan area we look at locales which are ten hectares locales distributed at random here they are only in the expansion area later we doing the middle of the city and in each

Locale we we look at the share of the land and streets so we look at how a share of streets that are less than four meters wide we look at different stages of the evolution of residential subdivisions whether it’s a domestic or informal layouts formal layouts or

Projects and we look at block size we look at intersection density some other ways that that tell us something about these layouts from high-resolution satellite imagery this turns out because we have 40 of those on the expansion area and then for the inside this is a very very heavy labor-intensive work

Because it has to be digitized and it takes time so we’ve actually opened an urban expansion observatory in Navi Mumbai in India and we have because of habitat 3 we now have 30 people working there trying to do all the digitizing and calculations before before the deadline which is like in three months

Time where we have to to finish that now in so here are some of the results which are actually quite astonishing you look at the Calcutta the urban fringe of Calcutta the the area that was built in the last 24 years now Calcutta one of the largest cities in the world with

Many planning organizations and development corporations and all of that right 92 percent of the land in the expansion area is found to be in a domestic housing namely completely unplanned housing just rural people dividing their land and selling selling plots to people who then go and bid 92

Percent there virtually no streets I mean the 8.4 percent of the land is devoted to streets where the normal expectation is about the global average for the entire expansion area is 20 percent and the kind of normal subdivision like the one I showed before for Lima is 25 percent so these people

Are at 1/3 of land and two-thirds of the roads are less than 4 meter wide so you’re beginning to see with this method something that we can say something about the quality of this expansion it’s not good it’s going to be very there the arterial roads are spaced many

Kilometers apart to get to work these places are going to be very difficult to integrate into the calcutta metropolitan labor market it’s very hard they’re actually creating a disaster and they’re way behind the in terms of provision of infrastructure and infrastructure compare let’s say to the Chinese who are

Doing something strange – I mean they’re building a lot of ring roads but at least they’re doing a lot of infrastructure and these people are doing no infrastructure law and it’s going to be very difficult to think of these cities as integrated metropolitan labor markets compared that functioning

In a productive way that they should be functioning the third phase of monitoring is actually surveys on the ground in these 200 cities so we have City based researchers in each one of these 200 cities very difficult to do some and in order to do that we were

Looking only at two issues for now but we can do more like we I was trying to say we can do water and sanitation we can do now these studies one of them is an affordability survey to look at the affordability of land and housing on the periphery of the

Global sample of cities the other one is look at the regulations governing governing land and housing and how they are affecting the development of these areas because the global sample is indeed global we’ve had to translate these questionnaires into ten languages and and find people that can that can do

That it kind of competent people to do them in every in every city this is the affordability questionnaire this happens to be Korean this is the regulatory questionnaire and this happens to be Arabic so it and we’re already have results for more than half the cities

And again like I said it has to be ready for Habitat 3 so it’s moving it’s moving very rapidly and you can see let’s say how many cities have green belts how many cities have regulations governing governing minimum lot size building height any restrictions on development

So you can already begin to see results now I’m saying this is the first time where we’re doing that so it’s not a perfect way of doing it but what we’re doing is creating a platform so that you can study the global sample of cities along many dimensions again and again

We’ve already got one of my colleagues who is an air quality person to measure a particular matter in these 200 cities so that we have the data for a particular thematic on all of the cities in the sample so it’s just a matter of gradually accumulating data for monitoring this global sample over

Time and what we’re trying to do is do it on the cheap so that you can repeat it you know if you took if each one of those studies called milk millions of dollars we could not repeat it so the idea is that we can do a study like that

In two hundred cities for three hundred thousand dollars right so that you can actually repeat it or do other similar ones again and again so if not three hundred four hundred so I move to the next second part of my talk which is the reason that we’re doing all this

Monitoring is not because we’re kind of a research organization but because we’re trying to influence mayor’s we’re trying to influence mayor is to say there’s gonna be a lot of expansion you better make some minimal preparations for it instead of letting it go which we then you get situations like Calcutta

You don’t want that you want orderly urban expansion you want the expansion to be productive inclusive and sustainable so how do you do that so we have devised a really simple program for doing that that basically has only four steps and that can be easily understood and implemented on the ground by

Municipal teams so we’re not even doing the planning or we’re just kind of hand-holding capacity-building educating these people how to prepare for their expansion so the four steps are the first to make realistic projections of the land needs over the next thirty years thank you second to expand city limits so that you

Can plan within this area because if it’s beyond your limits you’re not gonna be able to do anything and third to prepare an arterial road grid which what we’re saying is there are many things to plan for but you have to have some priorities in what you have to decide now

So we’re saying the most one thing for you to decide now is to create an arterial grid one kilometer apart of 30 meter rods in the entire expansion area and acquire the right-of-way for these roads now so that you know that you have some control over the development process and the first

Thing that we’re saying is protect public open spaces and that is like try to protect areas of high environmental risk from development and also try to make sure that there’s enough public open spaces in the expansion area so it doesn’t all get built up now the idea of

Creating plans for a six or seven fold expansion of the city sounds unrealistic but it has been done before there are two historical examples which are important to know one is the famous in San Chaplin for barcelona created by Ildefonso da 1849 so 1859 and this was a

Competition that he won and he stayed for 20 years to actually implement it on the ground so when you go to Barcelona you can actually see this these are kind of large blocks and the area of expansion that was planned was about nine times the the built-up area of the

City at the time the other example and even earlier one is the commissioners planned for Manhattan which you see here this was approved in 1811 the population of Manhattan at the time was about 90,000 people and it created an area for about a seven fold expansion of the city

In a kind of an ordered way that we recognized of course today the interesting story about and this was done by a governor Morris and a couple of other commissioners he’s one of the founding fathers he signed on the Constitution the interesting story about New York is

That it took about until about the end of the century for Manhattan to fill up with with building and then at 1897 when Manhattan was running out of land Manhattan New York City acquired the the four surrounding counties and added the Bronx Queens Brooklyn in Richmond County

Later renamed Staten Island to its land again increasing its area Sevenfold now the interesting thing about New York again with the tradition of the of building the grids in 1900 Lewis Reis chief engineer of the topographical Dept produced a plan for the entire five borough of gridded of gridded blocks and

Open spaces here you can see the proposed parks and this is Queens at the time of course there was nothing there and that area again a sevenfold expansion area was then filled in 35 years right so this kind of growth has happened before and is happening now as we speak

So the idea of getting people to think in terms of three times four times five times is not unrealistic once you get the numbers right so here’s one of our efforts we’re working now in a number of countries the two countries where our work is most advanced are Ethiopia in

Columbia in the t.o.p we started out with four cities bahir dar was shown here Hawass a’ a Adama and miquellee four regional capitals in the key Opia and we started out by by looking at there areas and they’re trying to project these built-up areas to give him an idea

Of how much the city is going to grow if we make some assumptions about population growth in density and we got the mayor and the municipal teams to come to a workshop in Addis a couple of years ago and we started to instruct them about how to create their arterial

Grid plants and the open space preservation plants here we see the the buyer diet team in in the workshop in in Addis now the the interesting thing in Ethiopia in general is the Minister for urban development and construction it find this thing very appealing urbanization is one of the key goals in

The for the government he has instructed these cities to provide him with plans and budgets they all have plans and budgets and all working towards the implementation of this program in terms of opening up the areas with arterial routes and protecting open spaces and this is progressing very quickly and in

The meantime 14 other cities have been added and urban expansion is being taught as a course in the ethiopian civil service university to hundreds of officials and basically the entire country has learned how to do urban expansion and this is for example that the plan for Micheli urban expansion the

People are now in the process of acquiring the rights of way for the arterial grid so there are teams of surveyors that are going on the urban periphery here you see one team laying out the road in the expansion area of wasa so what they are doing is they are saying in

The roads gonna come up to here you see the arrow here the roads gonna come up to here you have to move your house to the edge and if you move your house we’ll give you a 99 year lease on the land so this is happening very rapidly

In Hawass a’ which is leading the way they already have more than 60 kilometres of land laid out and they are starting to pave some of the routes so here you can see the clearing and the paving this is in miquellee an arterial road being gridded now the

Other country that we’re working in is Columbia and there are two cities in Columbia which are moving ahead one of them is Monteria the other one is via de Paris so again what you see here is their arterial grid for for Mont area and in Monteria their method for getting

The grid is a little bit different it’s just a matter of registering liens on the property titles of of the landowners on the urban periphery saying there is a there’s a road that’s going to pass here now the new mayors in the meantime we thought we’d finish it during a time of

The old mayors we didn’t so now there are new make the two new mayors are on board with this plan and we decided that for symbolic purposes even though the lands are not needed now that we want to plant trees along both along the sidewalks of these routes so now the the

Budgets have been secured for two large nurseries in both of these cities and the kids from the school are going to come and plant trees at 10 meter intervals along the entire rights-of-way over their arterial roads in the expansion area of these cities another city that we are working with is Reynosa

In Mexico sorry for the a typographical error here there this is a city that is growing extremely rapidly on the border and they are moving ahead again with their arterial road grid and are in the business of securing the land another city that the fastest-growing city in Latin America Playa del Carmen

In Mexico is another one will this tourism city on the coast south of Cancun that has made plans for its expansion and is now again in the business of securing the lands for this expansion so we our work we have other initiatives to work with countries we

Have started the project in Myanmar we have another project in China another project in Indonesia we’re working with Jim Spencer and another project in Mexico and we also have a World Bank a project in Rwanda so in Rwanda it was interesting because the people in Rwanda looked at what the Ethiopians are doing

And said we basically want the same thing can you help with Rwanda so we have a World Bank project in Rwanda and where we have all kinds of engagements with other countries what we’d like to do is kind of start pilot projects with four or five cities in the country

Usually two or two of them kind of move ahead the rest of them are behind and then this thing naturally grows to a natural to a national program so this is basically the summary of what we do thank you you

ID: alNUMmlYwgk
Time: 1464817826
Date: 2016-06-02 02:20:26
Duration: 00:41:34

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