Toolbox

This activity contains qualitative and quantitative tools that allow the description and calculation of future scenario (that might include desirable and undesirable situations) analyse their impacts on the territory and thus clarify and anticipate possible futures. Scenarios should be defined on the basis of a time horizon. They can also be calculated on the basis of short-, medium - and long - term projections. 

Scenarios can include the baseline or "as usual", the optimal, and the strategic. The first assumes that existing trajectories will not change in the future and conditions will be extrapolated from what is currently and has been happening in the past. It is important that this scenario is considered because it allows to visualise and identify what would happen if no action were taken in the urban development of the city, map any undesirable conditions, and plan to avoid them. The optimal scenario is the one where all strategic variables are considered to reach the best possible status, but which will not necessarily be feasible or achievable. The strategic scenario is the desirable scenario and considers what is realistic under current conditions. This scenario should be aligned with the vision and objectives that will be set out in the next activity. 

To build the scenarios, some assumptions need to be first established, defining what are the minimum conditions needed for each "as usual", optimal and strategic scenario to develop. To do this, review the narratives of each of the scenarios developed previously (T25 Scenario Building Narratives). Then, there needs to be a selection of variables that will be studied under each scenario. These can vary and depend on the scope of the planning process but need to be linked to sustainable development. Such variables include but are not limited to  population projections, urban expansion or densification demand, requirements for public space and urban services, etc. After the variables are selected, they need to be calculated for each of the scenarios.

To calculate population growth and urban footprint, the team can use T24 Demographic and Density Projection. This uses population census data to first estimate projections in a defined timeframe. Then, different scenarios can be studied. First, if no expansion is required, a projection of the new population density can be calculated, considering the population growth. Second, if a planned urban expansion area is needed, scenarios of the required urban land area can be projected, considering the current and other benchmarks of population density. Density averages by type of single-family or multi-family housing should be considered, as well as ensuring that the growth rate of the urban footprint (area that the city expands) is aligned to the projected population growth. It should be noted that suitability analysis (in T18 Analysis and Cartography Checklist) should accompany the planned urban expansion projections. As urban expansion often requires new infrastructure and social facility investments, densification and infill development options should be assessed prior to any expansion decisions.

Additionally, the T43 Facilities and Public Space Projections can be used to estimate the deficit and current coverage of each type of facility (healthcare, education, commercial, sports, cultural, etc.), as well as to determine the number of units of each type needed to cover, as the case may be, the current unmet demand and the future demand based on projections. The analysis should be carried out with special attention to the demand for facilities according to the scale of the city and its population. The tool also allows to calculate and compare the necessary public space surface and the current and future coverage, according to national ratios and international recommendations. It is important to clarify that this calculation is done on an aggregated basis for the whole city, and it is necessary to analyse the distribution of existing and future public facilities and spaces. In order to do so, the scenario building can be complemented with spatial analysis to evaluate which areas of the city lack accessibility to these facilities, defining buffers that correspond to walking distances (e.g. accessibility in 5, 10, 15 minutes), according to the scale of the city and the capacity of facilities. These analyses could be taken from Block D Analysis and Diagnosis.

Finally, it is recommended to estimate the provision of public services such as water demand, electricity consumption, sanitation services, solid waste management, road network infrastructure, etc. in order to know the demand for each type of service, and to establish a basis for the strategies to propose the amount of primary infrastructure or public investments required.