Neighborhood: 20 Saint Gervasi – La Bonanova, Les Tres Torres, Saint Gervasi – Galvany
Group: Maria Margariti, Renata Stefanelli, Liliana Viveros Diaz
ANALYSIS OF THE AREA
In the three neighborhoods Saint Gervasi – La Bonanova, Les Tres Torres and Saint Gervasi – Galvany the research fields that stand out the most due to its visual impact are vegetation, transportation and residencies. Located on the foot of the Collserola park the area presents a great amount of gardens and parks such as Parc de Monterols, Jardí de Les Tres Torres and Turó Parc and individual green areas in between the buildings by Les Tres Torres and Bonanova area. The occupational uses of the buildings in the area diverge with the access of transportation to the places. Along the main roads and subway stations in the area between the streets of Avenida Diagonal, Via Augusta, Ronda del General Mitre and Balmes, the buildings have a mixed use of commercial stores on the ground floor and residencies on the floors above. Along the rest of the area, there are mainly residence buildings, with few local services located spread out. In the northern part, towards Collserola, the typology starts changing; some houses can be seen between dense green areas unlike the high concentration of buildings side by side with internal patios in the block in the rest of the area.
OBJECTIVES OF THE RESEARCH
The purpose of mapping out the city in different aspects is to be able to transform Barcelona into a 0 emissions city. It is necessary first to find out what specific node pollutes and its effects. In order to have objective and accurate values only a section of the area was taken into consideration as a case study. Thirty blocks between the streets of Via Augusta, Ronda del General Mitre and Muntaner were chosen due to its intense flow of cars, buses, presence of railway stations, internal parks inside the typologies of the residences, public parks, and different heights and uses of the buildings around. Therefore this project consists of a research on the Co2 emissions of the pollutants of the area (traffic and buildings), the Co2 absorption by vegetation and its balance.
CO2 ABSORPTION BY VEGETATION
In order to compensate the CO² emissions of the case study region a research on the amount of absorption by vegetation was made. As a first step a map of the different typologies of vegetation was created, categorizing it in flowers, short vegetation, tall vegetation and trees along the streets. Through research, it is given that a tree absorbs 22,7kg CO² per year and has an average surface of 19,8m². Therefore, 1m² of vegetation with trees absorbs 1,15kg of CO2/year, but if the vegetation is short it is considered only 60% of that value. After all calculations were made, a map of the CO² absorption by vegetation was generated representing 250gr/m²/year of CO2.
CO2 EMISSIONS BY TRAFFIC
To analyze the traffic influence a research on the website www.bcn.cat/transit/en was made searching the hours with most traffic during the period of October 14th to October 21, 2010. The traffic of the region was mapped during the hours of 10am-12pm, 2pm-4pm and 8pm-10pm. Finally the time that represented the biggest fluency of cars and motorcycles was from 2pm-4pm. Therefore, to have even further accurate and specific data the number of cars and motorcycles that passed by per minute were measured in every corner of the case study region during those hours. Given the information that each car emits 145,9 g/km/min of CO² gases, a calculation with the emissions per block per street was generated and a map of the CO² emissions by traffic was created representing in 0.4tons/m²/year of CO².
CO2 EMISSIONS BY DENSITY
The use of energy in buildings is another pollutant source analyzed in the case study through density. The three neighborhoods had a population of 145,532 people in 2009 distributed in an area of 2.009,4ha. That gives a total population density of 72 inhabitants/ha. Saint Gervasi – La Bonanova has an area of 223,50 ha with a population of 46,829 people, giving a density of 109 inhabitants/ha. Les Tres Torres occupies 78,80 ha with a population of 15,832 and density of 201 inhabitants/ha. Saint Gervasi – Galvany occupies 165,9ha with a population of 46,829 people with a density of 282 inhabitants/ha. The area of the case study that contains the 30 blocks is 266,690m². Given that in 1m² of a house 0,014 tons/m²/year of CO² is emitted, a research of the amount of floors of each building was done. By calculating the total occupational area and multiplying by the CO² emission coefficient (0,014 tons/m²/year) a map of the buildings emissions of CO² through density was developed, representing 12.5 kg/m² O/year of CO².
CONCLUSIONS
Considering the great amount of parks and trees in the region, the hypothesis was that the pollution and absorption would finally balance out. Calculating the potential of each block to absorb its own CO² emissions produced by traffic and density through vegetation we were able to find out that the vegetation in the area doesn’t make up for its pollution at all. More specifically, we concluded that in order for the vegetation to compensate the traffic pollution we would need to have 1600 times more the amount of vegetation existent and to cover the pollution from residences and commerce it would be necessary to plant 100 times more.
