2.2.2. Ecological Footprint's Accounts

"The Ecological Footprint theoretically includes all human demands, but in practice, the relevant datasets are not available" [34]. Thus, taking into consideration the availability of datasets from similar studies [35,38] and trying to simplifying the Ecological Footprint calculations framework, the selection of the relevant parameters for energy and product consumption was implemented. The energy and product consumption were related to the needs of households, tertiary sector, municipal buildings, public lighting, public and private transportation, and tourism activities. The selected indicators for the Ecological Footprint assessment are presented in Figure 3, and an indicative sample of them is described in detail in Appendix A.

For the estimation of individual annual consumption, an inventory including indicative quantitative data is implemented. Depending on the availability of data, certain assumptions may be necessary. In order to improve the functionality of the framework, an algorithm that calculates the values of the individual indicators was developed providing that several inputs are known. The algorithm accepts numerous inputs, such as number of residents and tourists, number of buildings per use, area of dwellings, installed power, length of road and railway networks, numbers of vehicles per mean of transportation (cars, motorbikes, etc.), number of passengers and loads for commercial and passenger ships and airplanes, etc. (see Appendix A). The calculations were implemented taking into account assumptions, such as average weight of residents and tourists, average consumption of products per kg of human mass per day, average electrical and thermal energy per m<sup>2</sup> per use of

building, average surface of buildings per use, average time of public lighting's operation per year, average distance travelled by vehicles on local roads per year, average weight of loads for commercial and passenger ships, etc. (see Appendix A).

**Figure 3.** The Ecological Footprint's indicators per land use.

For the conversion of the aforementioned annual consumption in required biologically productive land, proper factors were developed with the application of LCA software (SimaPro 7.2) and the methodology Ecological Footprint V 1.02, and were used.

## 2.2.3. Equivalent Population's Accounts

An innovative part of the proposed framework is the calculation of the existing equivalent population that refers to the estimation of resident population (real and equivalent) of the study area, which contributes to the total annual consumption of resources and energy. The proposed methodological framework for the estimation of the total Ecological Footprint, besides the consumption needs of real residents of the study area, also takes into account the annual consumption of activities that do not depend directly on the resident population, such as the annual fuels consumption for personal transportation, which depends on the annual travelled km by all types of vehicles (cars, motorbikes, trucks, etc.), the annual energy consumption of tertiary sector buildings (hospitals, shops, offices, etc.) that depends on the surface area, etc. Consequently, an equivalence between the consumption needs and the equivalent resident was created, according to the Ecological Footprint that these needs require. By setting the real residents' population of the study area and their needs as a basis, the consumption needs of the remaining anthropogenic activities are matched to equivalent residents. Using this method, every real resident is matched to one equivalent resident, while all the other activities "produce" a corresponding number of equivalent residents. For example, a population of X equivalent residents can be sustained with the Ecological Footprint corresponding to the annual power consumption of tertiary sector buildings, or moreover, a population of Y equivalent residents can be sustained with the Ecological Footprint corresponding to the annual fuel consumption for personal transportation, etc.

The calculation of the existing equivalent residents which contributes to the total Ecological Footprint is implemented by considering the following hypothesis: if P\* real residents need EF\* (area in Gha) to be sustained, then what is the number of residents (Peq) able to be sustained in EF (area in Gha)? The existing equivalent resident population is therefore calculated using Equation (3):

$$\text{Peq} = \frac{\text{P\*}}{\text{EF}^\*} \text{EF} \tag{3}$$

where P \* and EF \* represent the population and the Ecological Footprint of the real residents, and EF represents the total Ecological Footprint of the spatial entity under study.
