Relation Between the Planning Decisions and Sustainability: Mersin Case

*Kadriye Burcu Yavuz Kumlu and Şule Tüdeş*

#### **Abstract**

Urban space is where significant socioeconomic processes are going on and maintenance of the socioeconomic processes is important in the sense of providing continuance of the daily life. Therefore, sustainability issues, nowadays, are highly popular in the sense of urban planning. In this study, the relation between the consequences of the planning decisions which shape the built environment and social and environmental sustainability is examined in Mersin case. For this purpose, the existing situation of the built environment is analyzed numerically in the context of land use, density, and neighborhood unit design, and a spatial index is developed in that sense, which indicates the existing situation of the built environment components of the study areas. Therefore, maps including spatial indexes are produced for each study area. Within this context, the first study area is CBD of the city; the others, namely, Pozcu and Mezitli, show the characteristics of subcentral places. Accordingly, questionnaires are conducted with the inhabitants of the study areas to determine their decisions related with the social and environmental sustainability. Then, whether there is a relation between the developed spatial index values and the results of the questionnaires is examined.

**Keywords:** sustainability, spatial index, central places, density, neighborhood unit

#### **1. Introduction**

 Urban planning is significant in the sense of maintaining the daily activities, by providing the continuance of physical, social, and environmental processes, which are going on in the urban sphere. The words "maintenance" and "continuance" are important in the context of sustainability, due to the fact that its main concern is focusing on maintaining or continuing these processes [1].

In this context, planning decisions related with land use, density, and neighborhood unit design have a vital role in shaping the urban environment, and it is significant in the sense of sustainability, both in the social and environmental contexts. Within this regard, in this study, the effects of the consequences of the planning decisions related with land use, density, and neighborhood unit design on social and environmental sustainability are examined. Therefore, planning decisions with regard to land use are considered in two dimensions as horizontal uses and vertical uses. Horizontal uses indicate the decisions which are shown in the urban plans. On the other hand, vertical uses indicate different urban usages as residential, commercial, etc. usages existing on a single building. Density-related

decisions are also conceived in two dimensions as residential and population density. Decisions related with the neighborhood unit design, on the other hand, consisted of five fundamental criteria as the existence of defined border and center, walkability, mixed urban uses and residential types, connected and walkable urban street layout, and the existence of various public urban usages.

In this regard, first, how land use, density, and neighborhood unit designrelated decisions are measured on the urban built environment will be explained. Second, the consequences of this measurement will be demonstrated by produced spatial index maps for central business district (CBD), Pozcu and Mezitli subcenters. Lastly, whether there is a significant relation between spatial indexes and the social and environmental sustainability will be clarified, based on the results obtained from the questionnaires.

#### **2. Measurement of planning decisions**

As described in the introduction section, the measurement process of planning decisions involves three main stages as measurement of land use, density, and neighborhood unit design. In the end of this process, spatial index maps indicating land use mix, density, and neighborhood unit design indexes are produced for each study area.

#### **2.1 Land use measurement**

 The consequences of land use decisions on the built environment are measured by using dissimilarity and vertical mix indexes. Dissimilarity index is used to calculate the horizontal use mix; on the other hand, vertical mix index is used to calculate the vertical use mix. Both indexes are used in the way they are used by Cervero and Kockelman [2].

The main logic of the dissimilarity index is indicated in **Figure 1** [3]. In general, the study area is divided into equal squares. Let us say there is commercial use in a particular square. Apart from this usage, the usages on the other surrounding squares are listed as industrial, commercial, residential, residential, commercial, commercial, industrial, and industrial, respectively. The initial square including commercial usage takes the value of 5/8 (0.625). The logic is the same for the other squares (**Figure 1**).

The calculation of vertical mix index is different from the dissimilarity index and has different logic [3]. It indicates the degree of mix use in a particular building. Let us say there is a commercial use on the ground floor and the remaining floors contain residential usages. Then, it could be stated that this particular building


**Figure 1.**  *Measurement of dissimilarity index [3].* 

*Relation Between the Planning Decisions and Sustainability: Mersin Case DOI: http://dx.doi.org/10.5772/intechopen.87836* 

has mixed use, since it involves different usages. For a study area including a large number of buildings, each building is identified as whether it is vertically mixed or not. Then, an agglomeration process is applied to determine how many buildings are vertically mixed in a particular square, as explained in **Figure 1**. It gives overall numbers, and then those numbers could be normalized to 0–1 or 0–100 range. In this study, the numbers are normalized to 0–1 range, due to the fact that dissimilarity index is ranged between 0 and 1. Then, the numbers obtained from the calculation processes of dissimilarity and vertical mix indexes are summed, and derived new numbers are again normalized to 0–1, in order to produce mixed use index.

#### **2.2 Density measurement**

The calculation of density involves two steps as the calculation of residential and population densities. Residential density indicates the total construction area, and it is measured by floor area ratio (FAR). Besides, population density shows how dense a specific area is, considering the total population living in this area. In this regard, population density is calculated as total population in a particular place divided by the total area of that place. In this example, measurement unit of population density is determined as person/hectare. As explained in the land use measurement section, the same logic is followed to determine the density index. First, FAR and population density are calculated. Then, obtained numbers are normalized to 0–1 range. Therefore, two different spatial index maps are produced which show residential and population densities. In the end, these two maps are brought together; in other words the numbers are summed and then normalized, and a single density index map is produced.

#### **2.3 Neighborhood unit design measurement**

 There are various criteria explained by different researchers to determine which criteria should be used to create ideal neighborhood units, and those related criteria have evolved along the planning history. In this sense, initial definition of an ideal neighborhood unit design was made by Clarence Perry in 1929. Perry emphasizes on six fundamental factors to create an ideal neighborhood unit as size, boundaries, open spaces, institutional areas, local shops, and inner street layout. In this context, first, he states that the size of the neighborhood unit should be determined by considering the population who uses the primary school, and the boundaries should be designed, evaluating the place and the users of the school. Second, the main arterial roads should not be located in the boundaries of the neighborhood, and those roads should surround the neighborhood. Third, open spaces should be designed as a system of small parks, and those parks have the characteristics of enabling entertainment and leisure purposes. Fourth, public institutional usages as schools, libraries, etc. should be located on the center of the neighborhood, so that people living in the periphery could also benefit from those areas. Fifth, local shops should be located on the nodes or near the periphery to provide the needs of the people living in the neighborhood or close neighborhoods. Sixth, inner street layout should not contain high volumes of traffic that endangers the pedestrians [4].

In 1994, the ideal neighborhood unit approach developed by Perry was updated by Duany and Plater-Zyberk. As it was in the Perry's approach, Duany and Plater-Zyberk have focused on the significance of the existence of primary school. The boundaries of the neighborhood should be designed considering the location of the primary school, and the ideal distance was identified as 400 m. Different from this, Duany and Plater-Zyberk have identified five fundamental criteria which an ideal neighborhood should have [5]:


Reaching today, one of the researchers who anticipate the New Urbanism approach, Farr has updated the criteria of ideal neighborhood unit design developed by Perry and Duany and Plater-Zyberk. The proposed neighborhood unit by Farr has 4000 m2 (approx. 0.4 ha). Similarly, the radius of the unit is between 400 and 500 m. However, different from the ideal neighborhood unit proposals, Farr has not focused on the existence of a primary school as an absolute must. In this sense, Farr has identified three main criteria as [6]:


 Along with these criteria, Farr has identified five fundamental characteristics which an ideal neighborhood unit should have. The first of these characteristics is the existence of the defined center and the boundaries. According to Farr, a person should perceive that he is in the boundaries of the neighborhood. Similarly, the center of the neighborhood should be perceived with the central usages. The other characteristic is the walkable size. Instead of using automobile or bike, one might prefer to walk in case the radius of the neighborhood does not exceed 400 m. The third characteristic is the existence of mixed land use and residential types, where there are various shopping alternatives and workplaces near the residential usages. Existence of different urban usages allows inhabitants to use different entertainment, sports, shopping, etc. activities in the neighborhood where they are living in. Besides, existence of different types of housing alternatives allows people with different sociocultural backgrounds to live together and supports social sustainability. The fourth characteristic is the interconnected and walkable street layout. The length of a building block should not exceed the walkable distance that a pedestrian easily goes through. Therefore, the presence of the small building blocks and frequently located nodes is significant to create a walkable environment. The last characteristic is the availability of different urban usages. Those usages should be located on the neighborhood as to provide equal access to each person living in the neighborhood. Explained five characteristics are illustrated in **Figure 2** [6].

Also, ideal neighborhood units proposed by three different researchers could be seen in **Figure 3**. As it is seen in **Figure 3**, the main characteristics which an ideal neighborhood unit should have are almost the same. These could be summarized as: *Relation Between the Planning Decisions and Sustainability: Mersin Case DOI: http://dx.doi.org/10.5772/intechopen.87836* 


In this study, five fundamental characteristics proposed by Farr have been evaluated for the calculation of design index. Among these characteristics, some of them are nonmeasurable. Therefore, measurable ones are selected to calculate the design index. In this regard, these could be listed as a walkable distance (approx. 400 m away from the primary schools), the existence of small building blocks (not exceed 180 m), and the existence of public urban usages (as count). Therefore, three maps indicating these measures are produced. For the following stage, these maps are brought together by summing the values, and a single map is produced. Then, obtained values are normalized to 0–1 range to demonstrate the design index. In this context, all of the spatial indexes could be seen in **Figure 4** for each study area. In the figure, dark-toned red indicates higher index values.

 As it is seen in **Figure 4**, CBD has higher mixed use index values, and the higher values are spreading over the surface in a homogeneous way. The reason behind this result is the fact that CBD shows central business district characteristics, which is the most lively place in the city with its different options for commercial, public, and other urban-related services. It is similar in Pozcu case, since it shows subcenter characteristics. Especially, the existence of forum shopping center has been growing

**Figure 2.**  *Five characteristics which an ideal neighborhood has, developed by Farr [6].* 

**Figure 3.**  *Ideal neighborhood unit designs proposed by Perry, Duany and Plater-Zyberk, and Farr, respectively [6].* 

**Figure 4.**  *Calculated spatial indexes for the study areas.* 

the commercial importance of the area, with its nearby environs. The situation is different in Mezitli case, because Mezitli shows the characteristics of single urban usage. They also could be stated as a subcenter; however, subcentral features of the area are weaker than in Pozcu. Therefore, the mixed uses are seen along the main roads which are frequently used by the inhabitants of the city.

 For the density index, CBD has low values. The higher density index values are grouped together at the peripheries, since the central areas in CBD involve higher volumes of commercial usages. Besides, the south of the area includes large public institutions. In Pozcu, there is more homogeneous spread of index values over the area. It is because Pozcu study area shows the characteristics of subcenter places. Namely, the area covers more residential usages than CBD. On the other hand, in Mezitli, density index values spread over the surface are more homogeneous than CBD and Pozcu, since the settlement pattern of Mezitli consisted of high-rise buildings with enormous vacant land between those structures.

 In the last, neighborhood unit design index is similar in the way it is spreading over the surface in both CBD and Pozcu subcenters, since they both could be considered as old settlement areas. On the other hand, index values are low in Mezitli subcenter, since it is a brand new settlement compared with the other study areas. Dominating settlement pattern in Mezitli includes high-rise buildings in gated communities.

In the view of such information, for the following section, the significant relation determined between the spatial indexes and social and environmental sustainability, depending on the results of the conducted questionnaires, will be discussed.

#### **3. Relation between spatial indexes and social and environmental sustainability**

 One thousand one-hundred and eighty-seven questionnaires are conducted (398 in CBD, 463 in Pozcu, and 326 in Mezitli) to determine the decisions of the inhabitants, who are living in the study areas, about social and environmental sustainability. In this regard, ordinal and multinomial logistic regression analyses were applied in order to specify whether there is a significant relation between the spatial indexes and social and environmental sustainability. The results of the regression analyses indicate that:


In the following section, depending on these results obtained from the regression analyses and the produced spatial index maps, conclusions will be discussed.

### **4. Conclusion**

In this study, spatial indexes are produced to determine whether there is an impact of built environment characteristics with regard to planning decisions related with land use, density, and neighborhood unit design-related urban planning decisions on social and environmental sustainability. In this sense, the following results are obtained:


 • Inhabitants of the study areas also state that the main impact on environmental sustainability is originated from pollution and the amount of carbon emission produced depending on the travel mode choice of the inhabitants as well as the distance between home and the workplace.

In the light of this information, this study is significant in the sense of producing urban policies related with social and environmental sustainability issues. Depending on the results of the study, required policies could be developed to maintain the processes of the urban areas.

#### **Author details**

Kadriye Burcu Yavuz Kumlu\* and Şule Tüdeş Department of City and Regional Planning, Gazi University, Ankara, Turkey

\*Address all correspondence to: kburcuyavuz@gazi.edu.tr

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Relation Between the Planning Decisions and Sustainability: Mersin Case DOI: http://dx.doi.org/10.5772/intechopen.87836* 

#### **References**

 [1] Yavuz Kumlu KB, Tüdeş Ş, Keleş R. Proposal of a multivariate method to measure the results of planning decisions which shape the built environment on the neighborhood unit scale. Planning. 2018;**28**(3):328-347

[2] Cervero R, Kockelman K. Travel demand and the 3ds: Density, design and diversity. Transportation Research Part D: Transport and Environment. 1997;**2**(3):199-219. DOI: 10.1016/ S1361-9209(97)00009-6

[3] Kockelman K. Travel behavior as function of accessibility, land use mixing, and land use balance: Evidence from San Francisco Bay Area. Transportation Research Record. 1997;**1607**(1):116-125

[4] Perry CA. The neighborhood unit: A scheme of arrangement for the family life community. In: A Regional Plan for New York and Its Environs. Vol. Vii. New York; 1929

[5] Duany A, Plater-Zyberk E. The neighborhood, the district and the corridor. In: The New Urbanism: Toward an Architecture of Community. 1994. pp. 17-20

[6] Farr D. Sustainable Urbanism: Urban Design with Nature. Hoboken, New Jersey: John Wiley & Sons, Inc; 2008

**547**

**Chapter 45**

**Abstract**

temperature

**1. Introduction**

climatic regions.

*Becky M. Ohiaeri*

performance as part of public response.

**Keywords:** adaptation, cost, climate change, impact, communities, flood,

Although climate change is fundamentally a global issue, its impacts are not projected to be felt equally across the planet. Prospects and constraints are unevenly distributed among global regions, communities, sectors, ecological systems, species, as well as across different time periods [1]. There remains substantial uncertainty on the rate and behavior of these changes [2]. For instance, [3] reports that climate change impacts are likely to result in extreme heat waves, droughts, desertification, floods, cyclones, wildfires, etc. in the tropical regions of the world. The Environmental Protection Agency [4] further suggests that, in addition to the regional variability of impacts, the scenario is likely to be further complicated by the sectorial variability of climate change (CC) impact even in contiguous

Adaptation Options for Tropical

of Kanshio, Benue State, Nigeria

Rural Communities: A Case Study

This chapter reviews how the built environments in the rural tropical communities of Sub-Saharan Africa are adapting to climate change. The research conducted an extensive study on present constraints to adapting the traditional huts in the "*Kanshio*" community of Benue State, Nigeria. It aims to understand the perception and sustainable adaptation strategies of *Kanshio* rural households toward the adverse effects of climate change impacts. Through survey, questionnaire, interviews, focus group discussion, and informal discussion, this study examines "perceived impacts of climate change on the current method of building" and "the adaptation strategies of households to the events of climate change impacts." Although the built environment in the tropical rural community is particularly vulnerable to climate change impacts, such as extreme temperature, droughts, desertification, flooding, and cyclones, they are the most poorly adapted and researched. The study finds that economic reasons were the most responsible for the lack of preparedness and adaptation. An additional finding was that considering and preserving the culture of ancient traditional architecture as an approach to improve building energy performance, room temperatures, and flood impacts are a worthwhile effort and creating awareness locally can help improve the building

#### **Chapter 45**
