Today we'll look at the question of diagnosis. Diagnosis is a term borrowed from the medical profession. To diagnose is to perform the necessary analyses to diagnose an illness. In other words to find out what problems the patient has, in order to come up with the appropriate treatment. By analogy, it is the same situation for territorial diagnostics. What we want to know is what the problem is, the state of the patient for as long as he is ill. And this is what we'll examine in the following minutes. Diagnostics brings up, above all, two questions. The first is <i>why</i> of diagnostics. What are its reasons and what are the questions it answers? It is critical to know how to respond to each question. We should not perform diagnostics for the sake of performing diagnostics, run the numbers for the sake of running the numbers or to have an encyclopedic knowledge of a territory. We must respond to the questions which arise. Next, the important question of <i>how</i>. What are the means and the approaches necessary? These are the two questions which will guide our diagnosis. Here's a very classic way to diagnose. We have our assets, and we evaluate the present and past dynamics of the territory. These can be economic, social, environmental or architectural. but we look at the presence or absence of certain problems or certain resources which are considered to be the assets of a territory. We try to understand the system's ability to function, and determine if, in its present state, it will enable us reach our goals. By analogy its weaknesses, which is the opposite. This is the evaluation of present and past dynamics, as with assets, but this time we'll instead focus first on what's not working in the system. This time we look at the possible developments of the territory, so we're looking ahead. We are symmetric with its assets, both present and past. With opportunities, it's the same idea of their effect on the system, but from a perspective and by analogy, of course, of possible threats. So we have here the past and the present, here looking ahead. Here we are with the positives, and here, with weaknesses and threats, in the negative. So here you have the grid for analysis, the initial framework. These are the questions we'll ask for a holistic diagnosis. A method of diagnosis by no means exhaustive. We have questions of institution, demographics, urban context, roadways, water, lighting, and surely others, here, without at doubt also the most important. Why? Because we will try to offer a vision of the city, of its past as well as its present. We'll highlight some of its weaknesses, but also some of its strengths. Because of this we are, at the same time, on political and institutional levels, as with questions of resources or other more complex issues of social context. Let's look at this example. The economic zone of a city, of Nouakchott. Each zone where there is economic potential is indexed. We'll soon see what becomes of it. It is not simply because we've identified a zone that it becomes useful for our planning, but it gives us an idea of where economic activity occurs within a city. Administrative questions, we're going to divide it up. We know that the city is divided into a certain number of municipalities, and we'll have the statistics for each municipality. This is always where the difficulty lies. If we plan for the whole of the urban perimeter, we still have subdivisions, whether by community or municipality. as a function of the cities they form part of. Another critical element is that of primary water resources. Right away we notice a deficit here, another large deficit in these zones, where there are few resources, This x-ray of primary water resources gives us a quick view of where the major problems lie when it comes to water supply. The stages of expansion. This helps us to understand how the city was developed, with indicators of each stage. We see that the initial nucleus was here, and how the city developed from it, with indications of the time periods during which this or that policy was put in place regarding the use of the territory. Existing subdivisions. We discussed earlier land issues, which are crucial here. Which is to say that all these indexed zones are subdivisions which were offered or sold, yet were not developed. In other words, all of these parcels are occupied. Which means that the city perimeter extends more or less to this point, and if today we want to develop a plan, all this zone is already occupied, even if in fact it is not, so our plan must begin a bit further out. A map such as this one offers a quick view of land issues. Another map, this one of urban public transport. This might be independent transport, or official transport by bus. Here were are perhaps dealing more with small-scale transport, but we see the breakdown of lines and stations. Roadways, both existing and also those, within the diagnosis, already planned, since we're not just planning, but also dealing with ongoing projects which take place over the next few months or years, which are already "in the pipeline", which means they will happen. We can, then, consider them as already existing. Densities. If we have a subsequent policy for land density, we need to know how we might apply this policy, in which neighborhood, know which neighborhoods are densest. We can easily see here that the densest neighborhoods are the poorer districts, with shantytowns here, and here, so we're dealing with extremely dense areas, with between 350-450 inhabitants per hectare. We see, when we superimpose these different maps, different resources, an idea of where the problems might occur, and what they might be. If we look at the map of water supply, we can see that this zone here is particularly problematic, because it is extremely dense yet has a scant water supply. Constraints, pressures, and environmental potential. In the case of Nouakchott, we have here these huge dunes, one of which protects from the ocean, and these areas of dry salt lakes, which are below sea level. This gives us a snapshot of the situation as it exists today in Nouakchott, where a breach of the dune ridge would lead to the flooding of this zone, and we see that this urban planning is, ultimately, dependent on the stability or instability of these large dunes. Land use. A supplemental map showing habitat zones, green spaces, the few industrial zones which exist, and, finally, a summary of the questions, with a few problems here, others here. This map tries, although doesn't necessarily succeed, but at least tries, to illustrate the issues behind this diagnosis. Quickly, another example, that of N'djamena, a city, like Nouakchott, of fewer than one million inhabitants. We have, of course, on this summary map all the problems, the potentialities, of the city of N'djamena. The most important thing is, of course, the map, but let's not forget that we also need a legend, for without it we wouldn't know to what the colors and arrows on the chart refer. So that was a brief overview of diagnostics. Don't forget the assets, weaknesses, opportunities, threats. This is the starting point we need in order to build and imagine a diagnosis. I've shown you several maps, and might have shown you others, or taken others away, but what you should keep in mind that a map is only useful if it assists you in your planning. If you make maps just for the sake of making maps, they will be useless. Each element that you bring to your diagnosis must contribute to your city planning.
