Hello, today we are going to talk about basic data. To make a plan or a diagnostic, a certain amount of basic data to work from is necessary. The basic data can vary, the most obvious ones being maps, satellite images, blueprints historical plans, all graphical things, the graphical representation of the city on plans. Those are the first data that can be provided. Then, we have other types of data called statistics, there is literature, there is the official data, there are field studies. Next come multiple tools that can be used for planning. Maps and images. A Google image as a first example. This is Madagascar. We go on Google Earth or Google Maps and we find most of the options that are before us, since we can quickly get maps and see the situation. There are always geo-referencing and scale issues. We must be able to measure things, from here to there or surface areas, so it's not always easy, but we do have a first source here, with Google images or satellite images bought by the city council or ministries. Another example on the coast, which shows a potential problem in this area, and we can start understanding the different urban fabrics here and there, just with an image. Here is Dakar. Simply observe this area here and the development of a new lot where only the road network has been built for now. Maps may also be historical maps or plan. Here is an old plan of Nouakchott, an image of Nouakchott from the 70's, and other types of documents which can be used as master plans, they are old master plans that we will be working on as well. So every time, we try to assess what has been done, and history is expected to carry on, something existed before, even if the plan didn't work. We will look for previous plans to assess them and see what has been established or not, what has worked or not and if it didn't work, in what extent and why it didn't. Let's see the statistics now. Let's pick any country and enter <i>« Institut national de la statistique »</i> or <i>« Office national de la statistique »</i> and you will find a website with the main stats for each country. Usually, it is national and regional stats. It's very difficult to find council stats and even more so at the urban area level, which is a gathering of several municipalities. So we must refer to national stats for mortality rate, for example, which is linked to the global population. Literature, broadly defined, includes all reports from experts. For each city, you will find dozens or hundreds of reports from experts on subjects from access to drinking water, focus groups, to socio-economic studies or socio-demographic studies in poor areas or general matters, previous planning, study reports on previous planning. You will definitely find a wealth of information. Just a downside to be careful about, usually in these reports, the figures are used over and over the previous reports are used to update the new ones without questioning the reliability and validity of the data. We can often trace, just like a historian, the progression of mistakes about the population and we find the source in one report, and see that the following ones have just copied it without checking the information. Pay special attention to this, reports are a source of information but the validity of the information must be known and understood. Official data. Besides stats, there are different types of data which may be land titles for example. Those can be found at the property, at the Land registry for cadastral plans. So there is a number of official data which can be used. They are often hard to obtain because generally speaking, whoever holds the data has the power, and it is very difficult to obtain full listings of land titles, for example. However, in some countries, the data are increasingly free and available for all. So we are going from a centralized view of the data, where nothing can go out and everything is kept very tightly as there seems to be no reason to be giving them away, towards a much broader view, which represents more the present days, namely to have basic data available to everybody. Finally, field studies. They can broadly be categorized. First, household survey where a questionnaire is made and it's carried out on the field, and the questions will be processed to create statistics. For everything needed that is not in the stats, or can't be found in maps and plans, reports and literature, or in official data, you must go on the field to lead the necessary surveys in order to obtain the data. A field survey may also be counting cars on streets. You place people and you count several hours a day traffic loads at given crossroads. They may also be household surveys, surveys, focus groups in districts in order to try and understand people's lives before starting to plan anything. It might be the most important part of our basic data. It's all the data that we don't have and that we must find and field survey is essential for this matter. This concludes this overview of the data issue. You need data and you can find only a few. In African cities, data is national, but not at town or municipality level, so it can prove difficult to obtain convincing information. It doesn't mean it doesn't exist, it's just harder to get. Everything you won't find you will have to go look for with field surveys, to set up methods that will allow you to quickly gather the data you need for your planning.
