Many researchers have suggested that criminal activities and urban growth changes are related. These studies have focused particularly on land uses, types of land use, and urban forms, such as the physical features of neighbourhoods [1
], roads [2
], shopping centres, and bus stations [3
]. However, knowing the correlation between expansion of urban areas and crime is very important for criminologists and urban planning decision-makers. In this paper, we attempt to investigate the link between the expansion of urban areas and the potential for crime by analysing satellite images over time together with the number of crimes committed during the same timeframe using remote sensing techniques.
Environmental criminology is a very important aspect to understand when dealing with crime and for crime prevention. Additionally, studying people‘s interactions with environmental factors, such as the points of transportation, work, shopping centres or even the outskirts of the city, can help in crime prediction [6
]. Boessen and Hipp have reported that although recent studies tend to split the crime study areas into small scales, such as streets blocks or blocks of houses, the surrounding areas have an extensive impact [10
Urban area expansion is one of the most critical types of worldwide change, and most urban areas are experiencing increased growth in population and infrastructure development. Increases in urbanization lead to many changes in the daily activities of people living within an affected area. Urban area expansions, over time, can also change the potential for crime [11
]. Usually, people are attracted to large cities because they are social and economic centres; however, this makes them more opportune places for crime to occur. Crime is an intricate issue, and many researchers have concurred that a connection between crime and land use exists [12
]. Theories about opportunity for crime suggest that crime and population are related; where there is a density of crime, there is a density of population [14
]. This opportunity increases when targets are found in an appropriate place and there is no surveillance in the urban area [15
]. Crime and the fear of crime blight and drain the social and economic vitality out of urban life [17
]. Urbanization increase and growing city environments have the potential to influence the timing and placement of criminal activities [5
]. Urbanization information, such as zoning and area characteristics, can help us understand patterns of criminal activity [22
Urban and neighbourhood changes, and government planning programs, play key roles in the increase in criminal activity [23
]. Commonly, urban areas around the world have had annual increases to their populations, which lead to increases in urban areas. However, planning and management of these increases are different from society to society and from government to government. Good urban planning in urban areas is playing an important role in the provision of a society’s needs, such as infrastructure development, ecosystem management, and safety controls, while poor planning leads to more societal problems, such as drugs and crime [24
]. Urban area expansion also affects cities at finer scales, such as at the neighbourhood level; thus, growing environments play an essential role in shaping the criminal activity within a given area [26
]. Some urban area combinations and designs can make chances for crime greater, such as blocking surveillance sight lines. By contrast, other urban combinations and designs can help in preventing crime [29
To create a safe environment, it is important to understand the link between urbanization change (increase) and opportunities for crime. Understanding the relationship between crime and urbanization will help us to make the right decisions and develop good strategies that can aid in crime prevention, as well as reduce the opportunity for crimes to be committed. It can also help police agencies so that they can be at the right place at the right time; that is, where we expect or predict crime to happen. In addition, it can assist in decisions, such as where to locate police stations when new ones are established and help determine which areas need more surveillance. Hence, the appropriate use of land can help build safer environments and help reduce the opportunity for crime [30
The relationship between urbanization and opportunity for crime has been studied by researchers who investigated theories in the field of environmental criminology [31
]. However, very few studies have considered urbanization change over time using remote sensing to study crime. Remote sensing techniques are powerful tools to analyse change, and it can help in such issues to detect the changes on the Earth’s surface. In 2013, Nazri examined the spatial relationship between urbanization and criminal activities in Malaysia. Although his study focused on urban planning, he established a strong association between neighbourhood increase and opportunity for crime. Stucky and Ottensmann [32
] have researched the link between violent crime and urban areas, and they investigated whether this relationship is affected by socioeconomic and demographic characteristics. They obtained a variance of results, where some non-residential areas had a high rate of violent crime, while some areas had lower rates. They also found some urbanized areas were affected by socioeconomic disadvantage. Zhang [33
] analysed the relationship between bus ridership and crime. He found that high population density and urbanized area characteristics catalysed criminal activity and tended to make it cluster crime around bus stops. In 2002, Schmitz and his colleagues have selected three images on three different dates to determine the increase in settlement in a particular area of Bredell, in eastern Gauteng, South Africa [34
Moving in the opposite direction, some researchers have studied the link between demolitions or decreases in urban areas and criminal activity. Frazier, Bagchi-Sen and Knight [35
] examined the relationship between demolitions and crime. The aim of their study was to identify the high and low hot spots of demolition and criminal activity over a five-year period when the city was shrinking. They found a relationship between demolition areas and migration and patterns of crime in the affected areas. The movement of crime was toward the city’s edges and suburbs. These findings can help in understanding the patterns of crime during the implementation of demolition projects in shrinking cities. In 1999, Cullen and Levitt analysed the link between city crime rates and population decrease. Sometimes populations decline and citizens migrate toward other cities to get better services in other urban areas. Highly-educated families tend to leave the city because of changes in the crime rate that affect their safety. Cullen and Levitt found a relationship between crime and urban flight, and their results suggest that every crime report corresponds with a decrease of approximately one person in the city population [36
Literature in environmental criminology confirms that there is a link between urban expansion and opportunities for crime to happen. In this paper, we investigated urban expansion and examined the correlation between urban area expansion and opportunity for crime. However, little research has previously examined this link digitally by using remote sensing techniques as a classification model to extract the exact urban expansions to compare with crime rates.
Rapid urban expansion in Saudi Arabia started from the period of the oil boom in the 1950s [37
]. Since that time, the three important urban centres in the country, Riyadh, Jeddah, and Dammam, have experienced rapid growth. Riyadh and Jeddah are some of the fastest growing cities in the world [38
]. For example, the spatial coverage of Riyadh was less than
in 1916 [40
] and, in the last century, the population of Riyadh was less than 15,000 people. Currently, it has around eight million people and it is projected to exceed 10 million by 2020 [41
]. Makkah province includes the holy city, Makkah, which receives millions of pilgrims every year [39
]. The second city in this province is Jeddah, which is growing in importance as a seaport on the east coast of the Red Sea. The peak growth of Jeddah was in the late 1960s, when it ranked as one of the fastest growing cities in the world [39
]. East Area, which is considered the richest oil area in Saudi Arabia, has most of the petroleum production companies. It includes the most important industrial city, which is Al-Jubail. For urban planning in Saudi Arabia, decision-making is a centralized process, so urban planning is a top-down process which is coordinated by the Ministry of Municipal and Rural Affairs across the country. This makes public participation and the ability to access planning data very limited [42
Modern spatial techniques are powerful tools to analyse such issues and investigate these types of correlations. They may be used to promote a better understanding and provide the right ideas to support decision-makers, helping them in the decision-making process regarding crime prevention.
This paper identifies, digitally, the link between urban expansion and the opportunity for crime, and seeks to answer the question of whether there is a relationship between expansion of urbanised areas and crime rates. It also shows the type of this correlation. Urban change detection models have become important tools for analysing the side effects associated with urban expansion over time. They can measure the consequences and causes of urbanization and urban growth and determine whether there have been economic or social effects. However, the objective of this research paper is to use remote sensing to analyse and test the relationship between the urban increase that has occurred from 2003 to 2012 and the opportunity for crime in Saudi Arabia.
Many researchers have suggested that criminal activities and land use changes are related. These studies have focused particularly on land uses, types of land use, and urban forms, such as the physical features of neighbourhoods [1
], roads [2
], and shopping centres and bus stations [3
]. In this paper, we attempted to investigate the link between the extension area of urbanization and the potential for crime by analysing satellite images over time together with the number of crimes during the same timeframe using remote sensing techniques.
Our findings show a positive association between increase in the urban area and the crime rate. The urban area change of Riyadh Province was 54.5%, and the analyses showed a correlation between urban change and the crime rate that was stronger than in the other provinces. Our findings also showed that in low-expansion urban areas, such as Tabouk (the change in Tabouk was only 8% during study period), there was no significant relationship between these two variables. It is clear that this correlation increases gradually whenever the urban expansion increases. The increase of the urban area in Makkah was 47.1%, and there was a noted correlation, but less than in Riyadh, where . The same held true in the East Area. Urban area expansion was 37%, and there was still a correlation, but less than in Makkah, where . Consequently, there is an increase in the crime rate where urban areas increase. These results support studies that confirm an existing link between expansion of urban areas and crime, where crime rate increases whenever urbanization areas increase. Accordingly, we can say that the study answers the research question of whether there is a relationship between expansion of urbanized areas and crime rates.
This also helps to explain the difference in crime rates between large and small cities. Criminals find more opportunities to commit crime in large cities than in small ones. In addition, the size and types of population are different between large cities and small ones. Workers, visitors, and migrants are considered as essential components of crime in large cities, while they do not have the same effects in smaller cities. Daily, people’s activities depend on land use and an area’s function. Crime place and crime density are different in any given city depending on how near or far they are from a city centre, shopping mall, or bus station. The opportunity for crime could be greater in commercial areas where there are elevated populations and targets during the day compared to residential areas [53
]. Information such as this aids us in understanding how a city’s land use corresponds to crime patterns across the urban landscape [54
Crimes are neither random nor unique, but they do share many features and characteristics [54
]. There are many factors that can affect crime rates related to land use change over time, such as city planning, economic considerations, distance from the city centre, neighbourhood quality, and police numbers. However, herein, our aim was to investigate the link between urban area expansion and crime. We found that there is a relationship between urban expansion and criminal activities, where this relationship increases whenever urbanization increases.
Land use change in urban forms is a notable phenomenon around the world and over time. Land use change detection models have become important tools for studying changes that occur over a given land. They help in analysing the effects associated with these changes over time, for both consequences and causes of urban and land use growth and their economic or social effects. In this study, we have used satellite images of our study area to measure urban change over a period of 10 years and test the correlations between these changes and the number of criminal activities of these areas. The results have shown that there is a measurable relationship between urban increase and criminal activity. Our findings support the crime opportunity theory as one of the possibilities, which suggests that population density and crime are conceptually related. A stronger positive correlation was found where there was greater urban area increase, and vice versa. There was a strong positive correlation between urban expansion and crime in Riyadh and Makkah Provinces (rs(8) = 0.697, p < 0.05). In Riyadh, urban increase explained 66% of the variation in the crime rate, while in Makkah Province, the coefficient also suggests a positive correlation (rs = 0.782). Urban expansion was 47% in Makkah. In the East Area, the correlation was not strong (rs(8) = 0.43, p > 0.05), where the correlation with urban area expansion was 37%. In Tabouk Province, there was no significant correlation between urban area expansion and crime, where the urban area increase was only 8%. Thus, we found the correlations were stronger where there has been a larger urban change. Many other factors that may affect the crime rate are not included in this paper, such as information on the spatial details of the population, city planning, economic considerations, distance from the city centre, neighbourhood quality, and police numbers. The sole aim of this paper was to investigate the link between urban area expansion and crime rate over time by analysing satellite images digitally. This study will be of particular interest to those who aim to use remote sensing to study patterns of crime.