MEASUREMENT OF URBAN SPRAWL AND COMPACTNESS CHARACTERISTICS NASIRIYAH CITY - IRAQ AS CASE STUDY

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 9, September 2018, pp , Article ID: IJCIET_09_09_035 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed MEASUREMENT OF URBAN SPRAWL AND COMPACTNESS CHARACTERISTICS NASIRIYAH CITY - IRAQ AS CASE STUDY Ahmed Shamkhi Jeber Al-Khafaji Centre of Urban and Regional Planning, Baghdad University, Iraq Nadia Abdul-Majeed Al-Salam Assistant Professor, Centre of Urban and Regional Planning, Baghdad University, Iraq ABSTRACT There has been increasing interest in urbanization since the mid- 1990s because of the directly related and a great importance in achieving the sustainability of cities. Where the debate took place at the priority of urban forms of actors that cause in the sustainability of cities, whether these forms express a sprawl or compactness. Many researchers have expressed for their absolute faith in the ability of specific urban forms to improve the environmental, Social and economic indicators for cities. Therefore, the studies have started to follow up and show out the characteristics and defects of each of these forms for the purpose of finding the best. The objective of the research was to identify and measure the characteristics of urban sprawl and compactness by adopting the hypothesis that "density is the determining factor in achieving the general features of urban sprawl or compactness. The research presented a review of the concepts of urban compactness and sprawl and the most important Previous studies on the subject. In addition, five important features were identified to determine the urban sprawl and compactness: type of clustering of development, centralization, proximity, diversity, ratio of blocks to the urban spaces. As well as the ways in which they are measured and the calculated values by which the degree of sprawl and compactness can be distinguished. The features and methods of measurement were applied to the study area of Nasiriyah city, as it was found to have a Polycentric clustering pattern as it achieved a value of 0.07 of the Moran global coefficient. It was also found to have a slight centralization and a slight degree of concentration in some areas to achieve a value of 0.25 which lies at an area equal to the population distribution. In terms of proximity, the calculated value of the city was greater than 1.2, which means that there are distances between the city areas. In calculating the diversity characteristic of the general land use of the city, it was found to achieve a value of 0.42, which means that the diversity of land uses is limited within the city, When measuring the ratio of blocks to the urban spaces, we find that the city has achieved the value of 0.183, which means that the city has a moderate percentage of urban spaces, that is, there is continuity editor@iaeme.com

2 Measurement of Urban Sprawl and Compactness Characteristics Nasiriyah City - Iraq as Case Study and non-dispersion of the developed urban area, of these five features could be identified as the study area that falls within the moderate sprawl concept. Key words: Urban sprawl, Urban compactness, Characteristics of urban form, Development clustering, Centrality. Cite this Article: Ahmed Shamkhi Jeber Al-Khafaji and Nadia Abdul-Majeed Al- Salam, Measurement of Urban Sprawl and Compactness Characteristics Nasiriyah City - Iraq as Case Study. International Journal of Civil Engineering and Technology, 9(9), 2018, pp INTRODUCTION Urban sprawl and compactness are important topics in urban form studies, which must be taken into account in urban development processes. Because of its effects that determine the sprawl of freedom or restriction of growth. This has a significant effect on the economic and free market as well as the nature of consumption of resources and increase pollution. As well as the social effect of overcrowding and social problems. Urban sprawl with spatial development forms include the following aspects: low population density, and the spread of new development without control. Which has greatly hindered the arrival of pedestrians and cyclists to their destinations, the establishment of retail complexes along the main roads, as well as shopping malls that have become centers of suburbs around large cities, and the adoption of private cars as a major means of mobility. Urban compactness refers to cities with high residential density and diverse use. Development is primarily within the city limits. This concept is closely linked to effective public transport systems and spatial arrangements that are concerned with walking or cycling. However, compactness may be interpreted and equated with excessive housing density. Therefore, it is known as recent overcrowding, lack of open or green spaces, and rising housing prices [1]. The term urban compactness "evokes in our mind the initial impressions of the densely populated Middle Ages, with daily activity in their walls as a result of form and size, and a combination of activities [2]. It is important to note that there are also other definitions of compactness on the basis of measurement, which is distinguished by measuring the distance from the house to the business area in the city center, and can be represented in a virtual city cylindrical with equal distribution of development in all parts, meaning the less the distance is the degree of compactness Above and vice versa, and in the same way can distinguish the urban sprawl [3]. Some previous studies have pointed to this subject. Burton pointed out that the absence of agreement on the preference of urban forms is the absence of reliable indicators in measuring urban forms. To focus its work on the role of urban forms embedded in the promotion of the social dimension, To identify indicators for measuring urban density by studying 25 cities for the purpose of identifying the variance in social indicators and their relationship to the degree of urban compactness and urban density [4]. Tsai contributed to the development of four quantitative variables to measure four dimensions of the urban form of large cities: population size, population density, degree of distribution of activities, degree of aggregation of densities, and adopted the method of analysis based on modeling and simulation, using the Gini coefficient and the global Moran coefficient to distinguish the compactness from Urban sprawl, as well as to distinguish density in cities (high, medium and low), as well as to distinguish patterns (Monocentric, Polycentric and decentralized [5]. Galster & elc knew the sprawl on the basis of eight distinct dimensions of land use patterns: density, continuity, concentration, pattern of clustering, centralization, nuclear, mixed uses and proximity. The urban sprawl achieves low values for one or more of these features [6]. In his study, Ewing editor@iaeme.com

3 Ahmed Shamkhi Jeber Al-Khafaji and Nadia Abdul-Majeed Al-Salam addressed four urbanization features: low density, scattered development, leaping development, Ribbon development. The last three features are phenomena based on the spatial structure of the sprawl form, unlike urban density-dependent urbanization. Commercial leaping development and Ribbon development often occur in certain parts of metropolitan cities, as the degree of sprawl in the metropolitan area often depends on several factors such as size and degree of non-continuity of development [7]. 2. GENERAL CHARACTERISTICS OF URBAN FORM The characteristics of urban form are a tool that can be used to distinguish between different urban patterns, including the sprawl and compactness forms. These characteristics provide an integrated spatial description to determine the urban form. This provides the possibility of measuring and distinguishing it from other patterns. These characteristics can be summarized as follows: 2.1. Measurement of the Development Clustering Characteristic Some researchers define clusters as a Clustering of development at the local level. Activities can be clustered in a multicenter or dispersed pattern [8]. If the central business area is the only place with dense development, the urban area will have a Monocentric Form structure. Conversely, when the same activities are scattered over several intensively developed areas, the number of nuclei will increase and a Polycentric Form pattern will be formed, each of which will comprise a cluster of activities representing a large proportion of total activities across the region. [6]. The spatial pattern of the city can be distinguished as a Polycentric Form by identifying two important issues. The first is to distinguish the centers by knowing the intensity of the labor, population or building density in these centers, and secondly: to identify and determine the distances between the sub-centers. [9]. In order to measure Clustering patterns, the global Moran's Coefficient is used, which can give the spatial correlation of the Monocentric, Polycentric Form, or decentralized pattern within the urban area [5]. By the following equation. Where N is the number of sub regions, X is the population or employment in sub region I, Xj represents the population or employment in sub-region j, X is the arithmetic mean of population or employment; Wj is the distance between two centers of two sub regions i and j, providing the possibility of measurement by giving A value ranging from ( ˉ1-1 ), Positive values express the clustered pattern, The highest value +1, with the city having one dominant position (Monocentric Form), and the positive minimum values reflect the polycentric form. On the contrary, the sprawl pattern (non- Clustering), is the maximum of -1, expressing the spread pattern of development. And the value 0 expresses the pattern of random (irregular) [5]. When determining this factor in the study area, using spatial analysis tools in the GIS program, by entering the information of the Neighborhoods in Nasiriyah city, also depending on the population, the area of study achieved the value of This value reflects the existence of a polycentric form in Nasiriyah city, as it occurred within the minimum positive limits. The table (1) and figure (1) show the report obtained from the GIS program, showing the period in which the pattern of the block Values and information entered for measurement editor@iaeme.com

4 Measurement of Urban Sprawl and Compactness Characteristics Nasiriyah City - Iraq as Case Study Table (1) entered information program (GIS) and computational values derived for the coefficient of Moran Figure (1) Report (GIS) for the analysis of the degree of pattern of development Clustering, as the city occurred at the beginning of the 2.2. Measurement of Centrality Characteristic The centrality reflects the degree of development distribution within the city, in terms of its concentration in a specific area, which is often in the central region (CBD) Or spread equally throughout the city, through which it is possible to distinguish between urban areas where most housing units and labor are located within limited spaces and relatively high densities and areas where development is distributed equally across the urban area. Or the extent to which labor and population are concentrated on the central business area as a reference point [10]. The loss of centralization is one of the most common characteristics of urban sprawl, Where it indicates the extent of development spread across the city's landscape started from (CBD) of the urban area, urban decentralization is often cited as a cause of long distances, long travel times and a cause of inefficient land use. [6]. The centrality degree can be measured by Gini Coefficient, where it is applied. The Gini coefficient is used to measure the distribution of population or jobs of spatial units within the urban area. Its range varies between (0-1), When the value of the Gini coefficient is close to 1, the factor is of high value and the population density or labor density is largely concentrated in a small central area, When the value of the Gini coefficient is close to 0, This means the population or employment is equally distributed throughout the urban area. The Gini coefficient can be calculated from the following equation [5]. Where N is the number of sub regions, Xi is the percentage of land area in sub regions, i to the total area, and Yi is the ratio of population or employment in sub region i to total population or employment. When applying the Gini coefficient in the study area, the city has a value of 0.25, meaning that the city is within the period of non-concentration of population within the city areas, as the population is distributed in all areas of the city but in a completely unequal manner. The Gini coefficient is calculated based on the Lorenz Coefficient. The latter shows the real distribution line of the population within the city (the curved line), based on the cumulative rate of the city's population and the cumulative rate of the city's living area. The editor@iaeme.com

5 Ahmed Shamkhi Jeber Al-Khafaji and Nadia Abdul-Majeed Al-Salam Gini coefficient is calculated within the equal distribution line, Figure (2) shows the linear and equivalent coefficients of the Gini and Lorenz coefficient and the asymmetry area Measure of Proximity Characteristic Proximity represents the degree to which different lands are used to be close to each other across the urban area. Proximity is the dimension that defines the typical distance between different uses.for example, proximity affects the range of employment and housing disparities for low-income workers, The average distance between Laborers and work areas, or the distance consumers spend shopping For entertainment or preview goods. The proximity of uses to each other is an important Characteristic affecting the Clustering of related activities within urban space, In theory, proximity is the average distance that people should travel from their homes to their destinations such as commercial, service, work and entertainment centers, Where the population must travel large distances in the case of spacing between uses, and therefore, there is more sprawl. [6]. The degree of proximity between urban areas can be measured by the Compactness Index, for the following equation: C When d It is the population weight of a specific area, depending on the population in that area, wi is their access to the central area (CBD). C is a cylindrical virtual city with a population size and the same area, with the requirement of equal distribution of population within the parts of this virtual city, Equivalent to the values of the two cities (index value = 1), this reflects the state of moderate distances between the city's areas, When the value of the city to be measured is greater than the virtual city value (index value <1), This reflects the Spacing between the areas of the city, And vice versa, where if the value is smaller, it near distances between the city areas [11]. When applying this indicator in the study area, it is found that the value of the indicator is (2.1). This means that the distances between the regions are slightly higher than the equal state, which confirms that there is one sprawl Characteristic in the city. Figure (3) shows the variation in access distances to the city center, as well as variation in neighborhoods density. Figure ( 2): Distribution of the population 2.4. Measurement of Diversity Characteristic Diversity is a multidimensional phenomenon that promotes more desirable urban Characteristics, such as diversity in housing types, density of construction, Size of households, ages, cultures and income. Therefore, the diversity Characteristic represents the editor@iaeme.com

6 Measurement of Urban Sprawl and Compactness Characteristics Nasiriyah City - Iraq as Case Study social and cultural context of the urban form, Diverse development includes a mix of land uses, types of buildings, housing, and architectural styles. As the lack of diversity of development leads to the similarity of the built forms, which often result in an unattractive urban townscape and monotonous, The lack of diversity of housing options, and different community groups depending on their income level. Also it causes separation of the level of society, the lack of balance function housing, which leads to increased use of private car, congestion and air pollution [12].In contrast to the compact urban form, urban sprawl causes separation of land use, Including the separation of homes, workplaces and services, as well as the separation of communities according to the income level, Reducing the mix of land uses in the community and increasing travel time, congestion and distance to move between housing and work [6], To measure diversity in a precise mathematical way, the Simpson coefficient is used, which can give the degree of diversity in uses and activities within the urban area by the following equation [13]. Where H represents the diversity coefficient, N is the number of uses to be measured; Ai represents the area of each use in the urban area. TA is the total area of the urban area. The value of the diversity coefficient ranges from 0-1, Where 0 expresses the dominance of one type of use in the region, and 1 expresses its full diversity. In order to measure this, the urban area was divided into a number of square cells using the GIS program, by the Fish net tool, the measurement of the diversity of the horizontal mix land use within each cell of 1 km², determined by a distance of 500 meters. After calculating the Simpson's value for each cell, the general average of the city is calculated, When this indicator was applied in the city of Nasiriyah, its value was (0.42), This shows that diversity is Less from acceptable limits, where there is relative dominance of residential use compared to other uses, Figure (4) shows the different land uses in the Nasiriyah city Measurement of Percentage of Blocks to Spaces Characteristic The development can be done within the districts, neighborhoods, streets and public spaces. It is generally composed of streets, spaces, urban blocks or individual buildings, where the human scale can be determined by the ratio of coverage, densities and Height within urban space for building. This is also related to the formation of the appropriate Urban Grain, which can be calculated by knowing the sizes of the building blocks and the number of their divisions. It was found that the permeability and accessibility are closely related to this Characteristic, where the scale and the appropriate divisions of building blocks allow the availability of good corridors that fit the movement of Pedestrians, As well as increased mobility options for the Pedestrians, and give better use of functions, and can determine the degree of harmony and homogeneity between blocks and urban spaces by the theory Figure Ground [14,15]. In general it can be measured Percentage of blocks to urban spaces by index called Porosity Index, measured by determining the percentage of area of urban spaces to the total urban area, as shown in the following equation [16]. ROS = sa/s x 100% Where (ROS) represents porosity index, (sa) is the total area of spaces within the urban area, (s) is the total area of the city within the municipal boundaries.the acceptable rate of permeability was Ranging from ( ). The high percentage of this value indicates that there is a discontinuity and lack of continuity of development, When it is reduced, this editor@iaeme.com

7 Ahmed Shamkhi Jeber Al-Khafaji and Nadia Abdul-Majeed Al-Salam indicates the high continuity of development and the lack of urban spaces within the general area of the city. When this indicator was applied in the study area, it was 0.183, thus within acceptable limits. The area of urban spaces within the city of Nasiriyah is 961 hectares, and the urban area is 5225 hectares, as shown in the Figure (5). The values of the five Characteristics applied to the city of Nasiriyah can be summarized in Table (2). Characteristic Development Clustering Centrality Proximity Diversity Percentage of blocks to spaces Table 1 Measure the characteristics of the urban form reality, Illustrate the results Method of measurement Value limits of Characteristic City value Illustrate the value Global Moran's Coefficient Gini &Lorenz Coefficient Compactness Index Simpson Index & Fish net 1km Porosity Index GMC=0 Random pattern 1> GMC >0 Clustering pattern 0>GMC >1- dispersed pattern 1<GI >0 0 = A situation equal to the distribution of the population in all parts of the city. 2=The population is largely concentrated in a specific area of the city. 1= CI Moderate distances 1 < CI Spaced areas 1 > CI Closed areas 1<SI >0 1=SI High diversity of land uses. 0=SI The dominance One type of land use. 0.2>PI >0.1 Moderate percentage of spaces 0.2<PI Large percentage of space 0.1>PI Limited percentage of spaces The value is from the area of the Clustering. The results are 0.07, meaning that the city is a Polycentric pattern, not a Monocentric pattern, Which appears in the case of extreme Clustering when the value approaches 1. The value is at an area equal to the population distribution but not zero, that meaning the population is distributed throughout the city but in a completely unequal way. The calculated value of the city is greater than 1, which means there is a relative spaced between the city areas. The calculated value of 0.41, that means there is limited land uses diversity. The calculated value of the city amounted to 0.183, which means that the city has a moderate percentage of urban spaces, there is continuity and non-dispersion of the urban area editor@iaeme.com

8 Measurement of Urban Sprawl and Compactness Characteristics Nasiriyah City - Iraq as Case Study 3. CONCLUSIONS 2. The study area has a Polycentric Form pattern, with a value of 0.07 of the global Moran coefficient. 1. When measuring the Centrality, it found that it achieves the value 0.25, which is located at an area equal to the distribution of the population, but this distribution is not in the case of absolute equivalence (when the value = zero). That is, there is a slight concentration in some areas. 3. Calculated proximity value of the city was greater than 1.2, which means that there are distances between the city areas. 4. The diversity characteristic of the public land uses of the city was found to achieve a value of 0.42 which means that the diversity of land uses is limited within the city. 5. Development Clustering in this study is found that the city has achieved a value of that means that the city a moderate proportion of urban spaces that there is continuity and non - dispersion of the urban area developed. 6. from the five characteristics can be determined that the study area is within the moderate sprawl concept, because all attribute values occurred in the sprawl area but did not reach the state of extreme sprawl, while at the same time far away from the values of extreme compactness. REFERENCES [1] Hołuj A, Lityński P. Conditions and improvements impacting urban sprawl in Poland. studia regionalia. 2015(43). [2] Thomas L, Cousins W. The compact city: a successful, desirable and achievable urban form. 1996: [3] Bertaud A, Malpezzi S. The spatial distribution of population in 48 world cities: Implications for economies in transition. Center for urban land economics research, University of Wisconsin [4] Burton E. Measuring urban compactness in UK towns and cities. Environment and planning B: planning and design. 2002;29(2): [5] Tsai Y-H. Quantifying urban form: compactness versus' sprawl'. Urban studies. 2005;42(1): [6] Galster G, Hanson R, Ratcliffe MR, Wolman H, Coleman S, Freihage J. Wrestling sprawl to the ground: defining and measuring an elusive concept. Housing policy debate. 2001;12(4): [7] Ewing R. Is Los Angeles-style sprawl desirable? Journal of the American planning association. 1997;63(1): [8] Anas A, Arnott R, Small KA. Urban spatial structure. Journal of economic literature. 1998;36(3): [9] Pereira RHM, Nadalin V, Monasterio L, Albuquerque PH. Urban centrality: a simple index. Geographical analysis. 2013;45(1): [10] Lee B. Urban spatial structure, commuting, and growth in US metropolitan areas: University of southern California; editor@iaeme.com

9 Ahmed Shamkhi Jeber Al-Khafaji and Nadia Abdul-Majeed Al-Salam [11] Malpezz S, "Estimates of the Measurement and Determinants of Urban Sprawl in U.S. Metropolitan Areas," Wisconsin-Madison CULER working papers 99-06, University of Wisconsin Center for Urban Land Economic Research. [12] Jabareen YR. Sustainable urban forms: Their typologies, models, and concepts. Journal of planning education and research. 2006;26(1): [13] Min H, Fengjun J, Fath BD. Measurement and spatial distribution of urban land use compactness in Chaoyang district of Beijing, China. Chinese journal of population resources and environment. 2010;8(4):3-9. [14] Coorey S, Lau S,Urban compactness and its progress towards sustainability: the Hong Kong scenario, Sustainable development and planning II, Vol. 1 87,2005. [15] Kadhim Naief Kadhim (Geospatial Technology for ground Water quality parameters assessment in Dhi-Qar governorate-iraq by using (GIS). (IJCIET), Volume 9, Issue 3, (Feb 2018). [16] Huang J, Lu XX, Sellers JM. A global comparative analysis of urban form: Applying spatial metrics and remote sensing. Landscape and urban planning. 2007;82(4): editor@iaeme.com