Urban upgrading of slums: Baghdad and London slums as study models for urban rehabilitation

This phenomenon of slums represents one of the most serious problems that Iraqi cities suffer from, especially the city of Baghdad, which has become teeming with a lot of slum buildings that have distorted most of its areas and neighborhoods. Most of the slums are in the form of scattered construction and chaotic gatherings that do not follow any planning standards. This paper aims to present and analyze the mechanisms of urban upgrading of two models of slums in the city of Baghdad and London. The treatment was through the urban development of these slums and the provision and improvement of services to reduce the phenomenon of total removal. The GIS program was used to calculate the urban variables and requirements, the optimal locations for services, and the total and partial removal percentages. The research achieved the lowest percentage of total and partial removal of the actual areas, which amounted to 7.31% in the first model and 14.26% in the second model. The slum area was also provided with all the necessary services in accordance with the urban housing standards specific to each city, to turn it into a residential neighborhood instead of calling it a slum region.


Introduction
Most of the world's cities face and suffer from the problem of slum housing, especially its urban or rural outskirts or in empty areas of the city (El-Shorbagy, 2020).This phenomenon has created a negative situation worthy of attention and follow-up because of its negative effects on the city and the nature of life in it (UNHSP, 2020).Slum areas are characterized by poor and negative urbanization, in addition to the imbalance inherent in the demographics and nature of society in these areas (Archer et al., 2020).
Informal areas are the areas located within the administrative boundaries of any city, which were established without land division plans.These areas may be built on public or private property with unplanned expansion (de Castro Mazarro et al., 2022).These areas may have small or large areas and the planning instructions do not apply to them and are divided according to their origin as follows (Alomari, 2020;Gevaert et al., 2020): 1. Slum areas that were built without obtaining building permits from the municipality.These are unorganized areas, lacking the necessary services, and the movement of cars in them is difficult, and such areas are difficult to develop.2. Semi-planned slum areas were built without licenses as well, but the housing units are distributed in an engineering way, and these areas are easy to deal with development.
As for the characteristics of slums, they are on two levels, the first level at the level of the slum housing area and the second level at the level of the dwelling in the slum area (Georgiadou et al., 2020).With regard to the first level, most of the buildings are not subject to the approved planning and engineering standards and were built without obtaining official permits from the competent authorities.Also, social services in those areas are distributed in a random manner that does not comply with the standards and controls of urban planning (Collado & Potangaroa, 2020).The road and transportation network are not planned geometrically and the width of the road varies from one place to another due to the random distribution of buildings, most of them are unpaved and the movement of vehicles in them is difficult due to their lack of planning standards (Okimiji et al., 2021).As for the infrastructure services (water network, sewage, telephone, electricity), they are below the standard that was designed for the service of all buildings, in addition to their poor efficiency.Most of the infrastructure services are not developed as they have been extended by bypassing the networks of the regularly built residential neighborhoods (Doe et al., 2020).Most of the buildings in these areas are not subject to architectural controls, which indicates the weakness of urban design that does not fit with urban planning standards.In addition to the lack of open and green spaces in these areas, they also lack a clean healthy environment (Okimiji et al., 2021).The important aspect here is also the imbalance in the population structure of these areas, which is characterized by weak and low levels of culture and education, high unemployment rates, low incomes and high population densities (Sinha, 2021).As these factors combined can be a source of danger and security concern to the neighboring areas.As for the second level, the structural safety factors are non-existent or minimal as a result of the implementation of housing away from oversight, study and proper engineering supervision.It is considered a distortion of the identity and architectural character of the areas where these slums are located, and there are no building regulations and controls (Denaldi & Cardoso, 2021).
Addressing the urban slum issue is of paramount importance, and governments and policymakers have turned to urban upgrading models as potential solutions.This paper aims to explore recent practices of urban upgrading models for slum redevelopment and its significance.There are many models of urban development for slums, including rehabilitation programs, urban upgrading of slums, upgrading for resilience, and integrated land tenure approaches.
Slum rehabilitation programs focus on in-situ development, aiming to improve the living conditions of slum dwellers while retaining them within the existing settlement.Such programs are designed to provide better housing facilities, upgraded infrastructure, and access to basic services.A study by Minna et al. (2021) highlights the effectiveness of a slum rehabilitation project in Mumbai, India, showcasing improved living conditions and enhanced community cohesion through the provision of proper housing and essential amenities (Minna et al., 2021).
Participatory slum upgrading models emphasize involving local communities in the planning and implementation processes.This approach recognizes the inherent knowledge and expertise of slum residents and seeks to empower them to actively contribute to the improvement of their living conditions.According to a study by Silva (2022), participatory slum upgrading initiatives in Brazil demonstrated increased community ownership, sustainable development, and social cohesion, leading to long-term positive impacts on slum areas (Silva, 2022).
In recent years, the concept of upgrading for resilience has gained traction as cities face the increasing threats of climate change and natural disasters.With regards to land tenure issues, it often underpins the challenges faced in upgrading slum settlements.Models that integrate land tenure regularization and property rights recognition have shown promise in improving tenure security, fostering investment, and reducing conflicts.A comparative analysis by Li and Ahmed (Li and Ahmed: Integrated land tenure approaches in slum upgrading: A comparative analysis of three regional cases, unpublished) examines the outcomes of integrated land tenure approaches in slum upgrading projects across different regions, providing valuable insights for policymakers.
Urban upgrading models for slum redevelopment have become vital tools in tackling the complex challenges presented by informal settlements.By reviewing recent references on the topic, we have explored the significance of various models, from slum rehabilitation programs to integrated land tenure approaches.Each approach has its strengths and limitations, and its effectiveness often depends on contextual factors.However, what remains evident is that addressing the issue of urban slums is not only a matter of infrastructure development but also a means to empower communities and ensure a sustainable and resilient urban future.As cities continue to evolve, policymakers must remain vigilant in adopting innovative and community-centric approaches to urban upgrading that prioritize the well-being and dignity of slum dwellers while creating inclusive and sustainable urban spaces (Li and Ahmed: Integrated land tenure approaches in slum upgrading: A comparative analysis of three regional cases, unpublished).
Most Iraqi cities suffer from a large number of slums and their growth is large as a result of the economic, social and cultural conditions and the weakness of the authority in controlling them (Sulistyaningsih et al., 2021).Most of the residents of the areas surrounding the cities have seized state-owned lands and built residential houses and industrial and commercial areas in them to turn the city of Baghdad into the largest Iraqi city in slums.This phenomenon produced multiple problems, especially in the field of various services, which contributed to the occurrence of many economic, social, service, environmental, population and housing problems (Saraiva, 2022).
Most of the urban development practices for the rehabilitation of slums in the literature mentioned in the research discussed the provision of alternative housing and appropriate services for the residents of slums and looked at ways to improve their living conditions and land ownership and make them able to face environmental crises, as well as the acquisition of new lands in different areas for urban upgrading in slums.None of this literature focused on providing the services and land uses needed by the population by exploiting the open spaces within these neighborhoods, nor did it focus on calculating the services needed by the population according to the standards and according to the number of residents, nor did it specify the appropriate location for the service within the slum.Therefore, the research aims to shed light on this problem, which was considered one of the trends practiced by the city's residents, especially the displaced to it, in order to obtain housing (Abed & Areej, 2019).The state, with all its institutions, has failed to find a solution to this phenomenon and to eliminate it, and to find housing policies with clear visions and landmarks capable of formulating plans of different dimensions and scopes to address this situation.In this study, some solutions to this phenomenon will be developed through some procedures and policies that are developed to rehabilitate or upgrade these areas instead of completely removing them (Kovacic, 2022).Therefore, two models of these areas were adopted, the first model represented a slum housing area in the city of Baghdad in the Banks district, while the second model is a slum area in the Harlesden district, which is located northwest of the city of London.Two models have been adopted to clarify the similarities in the spread of this phenomenon and the possibility of treating it in many cities of the world, not only in Iraqi cities (Rigon, 2022).To achieve the objectives of the research, geographic information systems were used to activate the criteria of urban upgrading, solve the problem of signing services and choose the optimal location for them with the least impact on the units built as slum housing.

Urban upgrading and rehabilitation of slums
The problems that led to the emergence of squatter housing varied in different countries, so it was difficult to define a model policy to solve these problems (Sunarti et al., 2019).Two modern concepts have emerged that carry a general character to confront slum housing issues (Abed, 2020;Kim et al., 2019): First: The concept of rehabilitating slums means providing these areas with the necessary infrastructure and social services.Second: the concept of urban upgrading, which does not necessarily mean only providing these areas with the necessary infrastructure and social services, but also includes re-planning these areas to revive the area and society on the one hand, and developing a strategy that works to link these gatherings with a comprehensive plan on the other hand to revive them.
The urban upgrading method includes the improvement of both the urban and social aspects, which means improving the existing housing, improving services and completing the missing ones, improving facilities, and supplying sites with them (French et al., 2021).It also improves living conditions and raises the level of the citizen culturally and socially.Such programs are carried out in coordination with the authorities responsible for economic, social, and environmental development while encouraging and developing self-efforts and community participation.Therefore, the concept of upgrading in slums was used to express the comprehensiveness of structural, economic, and social development within a strategic framework to address the problem of squatter housing in a radical and effective manner (Eneh, 2021).

Some of the policies and programs used to address the phenomenon of slum housing 6.2.1 Complete removal
Complete removal shall be in the areas where this policy can be followed and is characterized by (Mesplé-Somps et al., 2021): 1.A number of residents were allowed to be moved, and find alternative housing for them.2. A large crowding rate, and the presence of several families in the house.3. The region lacks basic services such as water, electricity, and sanitation, and it is difficult to provide them with services.4. Security problems.5.The existence of environmental risks and pollution that cannot be addressed.6. Lack of privacy, housing convergence, and narrow streets.

Partial removal
1. Partial removal is a style that deals with removal in a more moderate manner to avoid the damages that may be caused by complete removal from the social and economic aspects, and it requires (Bertelli, 2021;Ragheb & Barakat, 2022): 2. Determining the buildings that require removal, and setting priorities.3. Find a nearby location for temporary evacuation.4. Transferring residents to new housing, and removing vacated housing. 5.This process is repeated until all that needs to be removed is removed.6.In the absence of a nearby site for temporary evacuation, the residents to be evacuated are moved to the nearest area for temporary housing until the construction of new housing.
In this paper, two slums will be studied in two different countries, one of which is a slum in Iraq (in Baghdad, the Banuk area specifically) and the other in London (in the Harlesden area) in order to prove the possibility of applying the concepts of urban development and rehabilitation in any slum area.The research method will depend on building a model in geographic information systems for the rehabilitation of slums according to the urban housing standards of each country.Where each random neighborhood will be provided with the infrastructure it needs and the necessary services that meet the needs of the residents by choosing the best location for services that achieve ease of access and achieve the lowest rate of removal of existing housing units and prevent the evacuation of housing units and find alternative housing for the residents.

Urban development and slum rehabilitation by GIS-based decision-making
Geographical Information Systems (GIS) have emerged as powerful tools for decision-making in urban planning, particularly when combined with Multi-Criteria Decision Analysis (MCDA) and the Analytical Hierarchy Process (AHP).This integration allows for the creation of site-suitability models that enable informed and holistic urban development planning (Ullah & Mansourian, 2016).GIS offers a spatial platform to analyze, visualize, and integrate diverse geospatial data, which is crucial for understanding the urban landscape.MCDA is a methodology that aids in evaluating multiple criteria to make informed decisions.By combining these two approaches, planners can assess factors like land use, infrastructure, socio-economic conditions, accessibility, environmental aspects, and more, which are essential for urban development and slum rehabilitation.While the Analytical Hierarchy Process (AHP) is a structured decision-making technique that facilitates the prioritization of criteria and alternatives.It enables decision-makers to break down complex problems into a hierarchy of factors and subfactors, assigning relative weights to each based on their importance.For urban development and slum rehabilitation, AHP aids in quantifying the significance of factors such as proximity to transportation, healthcare facilities, education centers, employment opportunities, and social amenities (Manupati et al., 2018).
Combining GIS, MCDA, and AHP, planners can develop a site-suitability model that incorporates weighted criteria to identify optimal areas for urban development and slum rehabilitation.For instance, when rehabilitating slums, factors like existing infrastructure, proximity to services, environmental sustainability, and community cohesion can be considered.The MCDA process involves assigning numerical scores to each criterion, and through AHP, these scores are weighted based on their relative importance.The GIS-based model then integrates these scores spatially to highlight areas that align with the desired criteria (Balta & Yenil, 2019).
In recent years, several cities have successfully utilized GIS-based decision-making, MCDA, and AHP for urban development and slum rehabilitation.For example, the city of Medellín in Colombia utilized these tools to prioritize areas for public housing projects, considering factors like access to transportation, utilities, and community services.Similarly, Mumbai's Slum Rehabilitation Authority has employed GIS and AHP to identify suitable locations for slum redevelopment, promoting sustainable and inclusive urban growth (Caldas & Borcherding, 2014).

Urban upgrading models of slums 7.1.1 The model of the Al-Banuk district in Baghdad
Al-Banuk neighborhood is considered one of the large and newly established urban neighborhoods located in Iraq, northeast of Baghdad, in Al-Rusafa and administratively affiliated to the Al-Shaab district.The units of this residential neighborhood were distributed to government bank employees in 1980, with an area of no less than 600 square meters for each housing unit.The social fabric of various sects lives in this neighborhood.The neighborhood contains all services, residential, commercial, educational, health and mixed uses, and regular paved streets.The neighborhood's population is 9,570 people and covers an area of 1,118,700 m 2 .In the Al-Banuk neighborhood, there is a slum housing area adjacent to the residential complex for the professors of Al-Mustansiriya University, whose center is at the intersection of longitude E 44 ̊ 23 ̍ 55.68 ̋ and latitude N 33 ̊ 25 Fig. 1 A slum dwelling area in Baghdad, Al-Banuk neighborhood ̍ 7.68 , as shown in Fig. 1.This slum neighborhood was previously an open space dedicated to the green spaces of the Al-Banuk neighborhood.Still, after the war that took place in Iraq in 2003, and because of the weakness of the law and security at that time, this area turned into a slum housing area.Where many residents of the neighboring areas built random housing units in this empty space until it became crowded with residents with limited income.A modern and corrected satellite image of the city of Baghdad for 2022 with a spatial resolution of 0.6 and a geographic information system-GIS program were used to conduct statistics on housing units and population.All land uses in the study area were numbered based on the satellite image.The existing land uses in this area were residential use, open spaces, neglected spaces, small patches of water bodies, a network of unpaved dirt roads, and small commercial stalls branching out from the dwellings.This slum does not contain any commercial, educational, health, religious, or recreational service except for residential use.
The geometric calculations feature in the GIS program attributes table was used to perform the statistical calculations.Where the number of occupied housing units was calculated, the number of residents and the number of families in the region were estimated, in addition to calculating the areas related to the region, the area of housing units, and the empty spaces as shown in Table 1.The number of housing units in the slum neighborhood that was counted based on the satellite image reached 111 housing units, with a population of 666 residents, who constitute 7% of the population of the Al-Banuk neighborhood.The area of the slums was 33,223.20 m 2 , which constituted 3% of the area of the Al-Banuk neighborhood.The built-up area of random housing units was 20,070.93m 2 , with open spaces between these units with an area of 3,152.27m 2 .One of the most important challenges facing this neighborhood is its lack of basic services such as educational and health services, open and green spaces, infrastructure, and other services that the residents need.Where the residents of these areas depend on the neighboring neighborhoods for their services, for the services of water, electricity, and sewage, all of them were established irregularly and illegally, depending on the neighborhoods, which affected the services related to the housing adjacent to these slums.

Suggested services to rehabilitate the slum area
The urban housing standards of Baghdad City for the year 2022 have been relied upon to calculate the services needed by the region for urban upgrading and converting them into a residential neighborhood, as shown in Table 2.The area of each service was calculated according to the area allocated by the standards for each person, and then the total area was deduced based on the percentage of services and their total number, as follows: 1. Educational services (primary school): it does not need educational services because it corresponds to three educational buildings (kindergarten, primary, and intermediate) The number of housing units 111 units The number of families occupying the slum area

families
Total population 666 people, an average of 6 people per family 2. Commercial use (local market): 75% of the population served, and their number is 500.Each person is allocated an area of 0.75 m 2 of the total population.Therefore, the area of commercial use amounted to 374.62 m 2 .3. Health center: Each person is allocated an area of 0.35 m 2 , so the area of the health center becomes 233 m 2 .4. Green spaces: The total area of the proposed green spaces is 1700.87m 2 , given that urban housing standards allocate an area of 0.75 m 2 for each person.5. Transportation: Main roads with a width of 6 m and pedestrian paths with a width of 2 m are proposed.A parking lot of 700.5 m 2 was proposed due to the difficulty of entering vehicles near the residential units, as the urban housing standard was given 5 m 2 for 35% of the total number of residents.6. Religious services: a mosque to serve the residents of the area with an area of m 2 according to the area of 0.125 m 2 that the standard allocates for each person.
Choosing the best site for services Choosing the best location for land uses or services in a GIS (Geographic Information System) program involves a series of logical steps that leverage appropriate analytics tools to make informed decisions.Here's a step-by-step process: • Define Objectives and Criteria: Begin by clearly defining the objectives of the land use or service placement.Identify the criteria that will influence the decision-making process, such as proximity to the target population, accessibility, environmental factors, and economic considerations.By following these logical steps and using appropriate analytics tools within the GIS program, decision-makers can confidently select the best location for land uses or services, promoting sustainable and efficient urban planning and development.
The GIS program was relied on to choose the best location for the proposed services, based on the criteria of open spaces, removing as few housing units as possible, and taking into account placing the services in the center area.
The optimal location for all services was chosen in the same way, as a sequence of steps will be taken in the GIS program to choose the best location for commercial use as an example, as in Fig. 2a which shows these logical steps, and Fig. 2b, c, and d which illustrate the application of these steps in GIS.These steps shown below have been applied to all types of services to produce the final map of the informal neighborhood, which was developed and provided with all the required services related to the residential neighborhood.In addition to the design of roads that link the different land uses, as shown in Fig. 3. Thus, it has become possible to call this area a residential neighborhood after it has been improved urbanely.
As for the logical steps to choose the best site for commercial use using GIS: 1. Criteria: The goal will be to determine the best site for commercial use.The accreditation will be based on the urban housing standards adopted in the city of Baghdad, given that the commercial use center should not be more than 500 m away from the neighboring residential units, in order to facilitate access and be far from industrial uses and environmentally harmful uses.2. Input data collection and processing: The geographical data that the program will use is the land use layer with its areas calculated from the satellite image, and the digital elevation model of the region with the surrounding road network.The program will use the land use layer to define the areas of all uses and open spaces.As well as determining the levels of land uses so that the best location for the service is chosen according to the most suitable area and the best level according to the criteria that will be determined for the program.All areas of land use were calculated through the attribute table characteristics, and levels were defined for these uses, which ranged from 32.9-36.2m, according to the UTM coordinate system.Table 3 can show the collected data along with their sources.

Location analysis and a new data set were derived:
The minimum (200 m) and maximum (500 m) distance for commercial use from residential units was determined through proximity analysis.A slope layer has been created (Depending on DEM) in which the program will choose the site where the levels are as equal as possible.Through this analysis, the program calculated the distances needed by all land uses to reach commercial use.Then it chooses the best paths with the shortest reach for commercial use in some suggested locations.4. Reclassification analysis: Reclassification of layers according to the area of residence and the proposed area (374.62 m 2 ) and the lowest slope (not exceeding 3%).The program will display empty spaces and spaces that do not intersect with residential uses and other uses that have not been removed with the slightest slope.5. Weighted criteria, weighting and combine of the dataset: The raster calculator analysis was used to achieve the required condition for combining and reclassifying layers according to the desired service area.High weight was given to the spaces where commercial use is desirable (such as empty spaces given a weight of 10) to be placed according to the urban housing standard, and low weight was given to the undesirable space for each of the two layers of land uses and the digital elevation model after reclassification (weight zero and one were given for residential uses and built uses, as well as zero weight for levels greater than 34 m).The weights layer will be merged to get a layer with the best-suggested sites for commercial use.6. Choose the required area from the attribute table according to suitability modeling analysis: which is based on the standard area of use or service.That is, the best site for commercial use will be selected based on the data provided by the program in the attribute table after comparing it with the service criteria.The multi-criteria decision analysis (MCDA) was used and the weighted criteria were combined.
A suitability model was created and the program gave several proposed sites for commercial use after changing the weights more than once and evaluating the sensitivity of the results.The final site that fulfills the criteria for commercial use was selected.The remoteness of the service of the same type 5 Built uses 1 Land use area 4 Levels greater than 34 m 0

Residential uses 0
Table 4 shows the relative weights assigned to each land use and each objective to be achieved, according to importance in determining the service location in the Analytical Hierarchy Process (AHP).

Residential units completely and partially removed
In the slums area of Banouk, the number of housing units that were completely removed was 6 and the number of units that were partially removed was 2.
The total area of the completely and partially removed houses is 1467.31m 2 , which is 7.31% of the total area of the built housing units.
The intensity of land use in the Banuk neighborhood after development Depending on the areas calculated by the GIS for each land use, the proposed percentages of land use in the neighborhood were calculated, as in Table 5, which shows the intensity of land use in the study area.40% of the area of the slum has been exploited in its urban development and rehabilitation, as 1.12% has been allocated for the establishment of local and commercial markets that serve the population.A health center was proposed, representing 0.7%, a mosque representing 0.2%, and open spaces representing 7.6% of the total sum area.The road network and parks allocated to it accounted for 13.5%.No space was proposed for educational use, given that the slum is surrounded by two primary schools, a middle school, and a high school.
The proportions of uses that have been proposed will contribute significantly to the social and economic development of this neighborhood and will contribute to the increase in the value of the land and the achievement of justice and social equality among the population.
The lowest percentage of total and partial removal was achieved through GIS software tools compared to the current total area.The lower removal rate will enable decision-makers to find replacements more easily and at a lower cost.In addition, proposing services within these areas will enable the residents of these areas to be isolated from neighboring areas and facilitate the conduct of population statistics so that the area is gradually developed and can be combined with residential neighborhoods in the future to be included within the city's master plan.

Harlesden district model in London
The Harlesden neighborhood, nestled in the northwest quadrant of central London, has experienced significant urban changes over the years.Its strategic location, vibrant history, and diverse community have made it a focal point for researchers and urban planners alike.
Harlesden's geographical coordinates place, make the neighborhood an essential component of the city's urban landscape.The neighborhood is bordered by the Grand Union Canal to the west and the North Circular Road to the north, providing vital transportation links.Recent demographic data reveals a dynamic and multi-ethnic community, reflecting London's cosmopolitan nature.
It is estimated that the size of the population has grown significantly in recent years to reach, according to 2022 estimates, 20,076 people live in an area of 1,563,000 m 2 , which has led to an increase in the demand for housing and utilities (Smith, 2023).
Harlesden comprises a mix of housing units, ranging from historical Victorian-era buildings to contemporary apartment complexes.The neighborhood caters to a diverse range of residents, including families, professionals, and migrant communities.As property prices rise in central London, Harlesden has become an attractive option for individuals seeking more affordable housing.
The land uses in Harlesden vary, encompassing residential, commercial, and industrial zones.The neighborhood's central location and proximity to transportation hubs have made it a commercial hotspot.However, this rapid urbanization has also resulted in challenges such as inadequate infrastructure, limited public amenities, and deteriorating living conditions.One of the pressing issues in Harlesden is the emergence and growth of slums.Recent references indicate that certain areas within the neighborhood have experienced neglect, leading to substandard living conditions for the residents.Factors contributing to slum formation include urban decay, housing shortages, poverty, and social inequality (Brown, 2022).
The slum area of Harlesden, which is located at the intersection of longitude W 0 14 ̍ 54.24 and latitude N 51 32 ̍ 28.32 , shown in Fig. 4. Using satellite images and a GIS, the number of inhabited housing units, the number of residents, and the number of families in the region were calculated, in addition to calculating the areas related to the region, the area of housing units, and the open spaces as in Table 6 which illustrates the statistics of the Harlesden slum area.It was found that the slum contains 129 housing units and the number of residents was 774 people, whose percentage is 3.9% of the population of the Harlesden neighborhood.The slum area calculated by GIS was 20,242.779m 2 , which constitutes 1.3% of the neighborhood's area.As for the areas occupied by the construction of random housing, it was 9388.0704m 2 , interspersed with open spaces with an area of 10,854.705m 2 .The current land uses in this slum area do not exceed residential use and open spaces, and one of the most important challenges facing the development of slums here is the insufficient infrastructure and the lack of basic land use services (educational, commercial, industrial, health, open and green spaces) that made the residents of this area depend on the neighboring neighborhoods to meet their needs.
The proposed services for the rehabilitation of the slum area in Harlesden The urban housing standards of the City of London were relied upon to calculate the services that the region needs for urban upgrading and converting it into a residential neighborhood, as follows: 1. Educational services (primary school): The number of children benefiting from the primary school service is 144 children, based on (17.5% of the total population benefiting from the service).Each child is allocated an area of 3 m 2 , so the area allocated to the primary school becomes 406 m 2 of the neighborhood's total area.2. Commercial use (local market): The percentage of the population served is 75%, with several 581 people.Each individual is allocated an area of 0.75 m 2 of the total population, so the commercial use area is 435 m 2 .
Fig. 4 A slum area in Harlesden, London (Brown, 2022) Table 6 Statistics related to the slum area in the Harlesden area in London The total area of the slum region 20,242.779m 2 The total area of the constructed housing units (in reality)

m 2
Open spaces area 10,854.705m 2 The number of housing units 129 units The number of families occupying the slum area

families
Total population 774 people, an average of 6 people per family 3. Health center: each person is allocated an area of 0.35 square meters, so the area of the health center becomes 271 square meters.4. Green areas: The total area of the proposed green areas is 1700.87square meters.5. Transportation: The main roads were proposed with a width of 6 m and paths for the pedestrian with a width of 2 m.Car parks were proposed with an area of 728.5 square meters, due to the difficulty of entering vehicles near the residential units.6. Religious services: a church to serve the residents of the area.
Choosing the optimal location for placing services In the same way, as in the first model, the GIS program was relied upon to choose the best location for the proposed services, as well as relying on the criteria of open spaces, removing the least possible number of housing units, and placing services in the center.
The optimal location for all services was chosen in the same way, as the sequence of steps in the GIS program to choose the best location for the primary school as an example is shown in Fig. 5a, b, c.Where the GIS program was provided with urban housing standards that achieve the minimum distance to reach school, so that it does not exceed 5 min walking for a child to reach from his place of residence to school (meaning that the distance standard does not exceed 500 m as the maximum distance a child walks to reach school).Neighboring schools must also be taken into account so that the school site is in a place that does not contain schools (and given that the slums are devoid of any educational use).And also achieving the required area for the school according to the area allocated by the standard for each student (the required area for the school is 406 m 2 ). Figure 6 shows the transformation of the slum area into a residential neighborhood after urban development and providing it with all services related to the residential neighborhood.Completely and partially removed housing units 1.Since each housing unit in the slum has its own number, the numbers of the housing units that have been completely removed are (15,40,49,50,51,52,58,59,65 ,66,68,78,79,90,102,124), where the total area of the removed houses was 1235.86 square meters.2. Numbers of housing units that have been partly removed (53,62,63,92,93,96,105,123), where the total area of the removed parts was 102.505 square meters.
3. The total area of the completely or partially removed houses is 1338,365 square meters, which is 14.26% of the total area of the built-up housing units.
Land use intensity in Harlesden after development Depending on the areas calculated by the GIS program for each land use, the areas and proportions of the proposed land use in the neighborhood were calculated according to urban housing standards, as in Table 7 which shows the intensity of land use after development.
Approximately 60% of the total area has been used to rehabilitate this slum, with 2.01% allocated for educational services, 2.15% for commercial services, 1.34% for a health center, and 0.23% for religious services.Spaces for roads and parking lots were allocated by 20.05%, while green spaces occupied a large percentage of the total area, amounting to 8.40%.Rehabilitation will make this neighborhood compatible in the urban landscape with the rest of Harlesden, reflect positively on the heritage of this neighborhood and its historical buildings, and encourage the rehabilitation of slums in the neighboring areas.
It is necessary to take care of the elements of the green infrastructure of the slums after their rehabilitation  through afforestation of the borders of the slums to increase the percentage of green areas and to act as a buffer against wind and dust that spreads in most regions of Iraq.There are also many slum areas that have become garbage dumps, and many of the residents of these areas work in garbage collection.This can educate them to work on sorting and recycling this waste instead of throwing it in the garbage dumps adjacent to the slums.

Conclusions
Many studies have explored slum redevelopment using different methodologies, while GIS offers a significant advantage over the traditional methods used by previous studies.In this paper, GIS technology played a pivotal role in understanding the spatial dynamics of slums and the impact of urban development initiatives.By integrating geographic data with urban housing standards and socio-economic demographic indicators, the GIS allowed a comprehensive analysis of land use and decision-making for the appropriate location for services and infrastructure.Through satellite imagery, digital elevation modeling, and ground data collection, the GIS has created detailed maps highlighting the distribution of slum buildings and identifying areas that require intervention.The areas that required intervention needed urban upgrading, infrastructure development, and improved services and control over them.GIS helped select the most appropriate sites for these interventions based on land use distribution in slum areas and their specific needs.It also helps monitor the expansion of these neighborhoods, identify potential bottlenecks, and ensure efficient resource allocation.
GIS is indispensable in the analytical validation of urban development solutions.By overlaying socioeconomic data on slum maps, researchers and policymakers can assess these interventions' impact on residents' well-being.Indicators such as levels of income, education, health, and crime rates can be spatially analyzed to measure the effectiveness of development initiatives.This information allows for evidence-based decision-making, ensuring that resources are directed to areas of greatest need.
Case studies in Iraq and London demonstrated the effectiveness of urban upgrading solutions in slums when combined with GIS analysis.For example, infrastructure development and better housing have increased property values and improved living conditions.The impact of ease of access to schools, health centers, and commercial centers positively led to the creation of community spaces that promote social cohesion and empowerment.
Furthermore, GIS enabled cost-effective planning and monitoring and prevented the inefficient allocation of resources.By being able to visualize data on maps, stakeholders can better understand the challenges faced by slum dwellers and develop targeted strategies to address these issues.As a result, GIS-supported urban development solutions have shown great potential to transform slums into more sustainable and resilient communities.
Therefore, the research problem has been addressed and its objectives have been achieved by analyzing the problem with the tools of the GIS program, and by developing a model for urban upgrading in the slum area, providing it with the required services according to urban housing standards.Thus, the slum area is transformed into a residential neighborhood and linked to the neighboring residential neighborhoods.Also, the results have proven the research hypothesis, where the urban upgrading achieved the lowest percentage of the total and partial removal of housing units in the slums area after providing them with the required services.The most important conclusions reached can be summarized as follows: 1.In the slum located in the Banuk, 40% of the area of the slum was used to rehabilitate and provide it with the services that the residents need.As for the slum of Harlesden, 60% has been exploited for development.These percentages indicate the presence of large spaces within the slums that can be exploited to provide these areas with the required land uses without the need to provide additional adjacent spaces or remove a large part of their housing units.2. In the first model of the slums, the percentage of houses that were completely and partially removed was 7.31%, and in the second model it was 14.26%.These percentages are considered good if they were achieved when rehabilitating the slums because they achieved the lowest percentage of the removed areas.
Achieving this low rate of demolition will enable the authorities to provide alternatives to families with removed housing units, instead of the authorities having to provide them with an entire neighborhood.3. Since these areas lack regular networks of infrastructure services and road networks that connect them with the neighboring neighborhoods, the spatial analyzes in the GIS program is considered an opportunity to plan these areas according to the criteria adopted by the neighborhood, because it will determine the best location for the service according to the required area standard that corresponds to the number of residents.4. The spatial data that was used in the GIS program, such as the satellite image of 0.6 m and the DEM of the region, proved the effectiveness of GIS systems in rehabilitating slums, urban upgrading them, and choosing the optimal location for the proposed ser-vices in the region according to the criteria at the lowest economic cost. 5.A slum area can be considered a residential neighborhood if it is properly rehabilitated and by the criteria for urban housing.Where it is possible to register housing units in the names of their owners in the municipality to become regular by the law that protects the owner and guarantees the rights of the state to pay bills and taxes.6. Poor oversight by government agencies in following up and stopping this residential invasion leads to the transformation of most areas of the city into slums.This transformation leads to a change in the gender of the land use in the master plan that the authority determined as a law, and leads to the exploitation of the open and green spaces of the residential neighborhood.7.All buildings in these slums did not obtain official building permits, and they lack building and urban planning controls.This leads to a distortion of the visual view of the neighborhood and leads to the owners of housing units encroaching on the infrastructure of the neighboring areas.

Recommendations
1. Emphasis on activating the role of government oversight agencies to limit (or prevent) the recurrence of such a phenomenon in the future in other areas, while stopping any new construction works in these areas in order to maintain a minimum level of environmental safety.2. Providing the city's infrastructure according to a well-studied plan requires determining the locations of the slums, identifying the slums that can be developed and the type of services required in them.This requires conducting periodic statistics on slums in the city, the number of families and their members, and determining the identities of residents and the sources of their migration.This facilitates identifying specific sites for development and upgrading and building housing units for them according to their standard of living.3. The rehabilitation of slums requires the construction of housing units commensurate with the urban fabric of the city in order to achieve a healthy and safe structure within the general planning of the city.That is, when adding or rehabilitating any residential unit in the slum neighborhood, it should be compatible with the general texture and visual landscape of the character of the city and the neighborhood.
4. The complete removal of slums that can be removed, especially in the city, and compensating their residents by adopting a policy of vertical construction with certain heights commensurate with the needs and nature of the residents of the neighborhood.Vertical construction provides housing for many families within a smaller area, and facilitates the process of control and counting for families with limited income.5. Activating the role of the relevant institutions in setting up specific mechanisms (technical and organizational) to confront random housing.This requires finding laws and legislation commensurate with the problem without referring to coercive laws that humiliate human dignity and prevent them at the same time from encroaching on public and private property.

Fig. 2
Fig. 2 Logical steps for selecting the best location for commercial land use using spatial analysis in GIS.b Creation of slope from spatial analysis and definition of land uses levels and Reclassification to slope.c Reclassification to the building area that does not intersect with residential uses.d The combined layers are analyzed by a raster calculator and given weights according to criteria.e Select commercial land use depending on desired area

Fig. 3
Fig.3The slum area in the Banuk neighborhood after rehabilitation and development

Fig. 5 a
Fig. 5 a Input data set (layer of land use and digital elevation model) and reclassify layers according to the area of residential and open space and minimum slope.b Giving weight to the desired and undesired spaces according to the urban housing standard, and combining data sets and reclassify them by using a raster calculator.c Choosing the optimal location for the primary school according to the desired area according to the urban housing standard

Fig. 6
Fig. 6 The slum area in the city of Harlesden after rehabilitation and development

Table 1
Statistics related to the slum area in the Banks neighborhood

Table 2
Urban housing standards for the city of Baghdad according to the type of service (M.O.C.H, 2022) Run multiple scenarios by altering the weights and criteria to assess the sensitivity of the results.This helps understand the impact of different factors on the final location selection.• Visualization: Present the results through clear and interactive GIS maps, charts, and graphs.Visual representations aid in better understanding and communicating the findings to stakeholders.• Decision Making: With the results from the suitability model and scenario testing, make an informed decision on the best location for the intended land use or service.Consider other factors like cost, local regulations, and community feedback when making the final decision.• Monitoring and Adaptation: Implement the chosen location and continually monitor its performance.If necessary, adapt the land use or service placement based on real-world feedback and changing conditions.

Table 3
Geographical and spatial data collected on the study area and its sources

Table 4
Assigning relative weights to the criteria according to their importance in determining the location of the service in the Analytical Hierarchy Process (AHP)

Table 5
Density of land use in the slum-developed area in the Banuk neighborhood

Table 7
Land use intensity in the developed slums in Harlesden