تحلیل وضعیت نورپردازی و ارزیابی ایمنی فضاهای شهری با استفاده از راهبردهای CPTED و مدل ارزیابی Safety Audit (مطالعۀ موردی: پارک ملت شهر زنجان)

Introduction
Paying attention to the concept of security for citizens and its promotion has become one of the main priorities of the urban theorists, managers, and planners. Apart from its social and cultural effects on the patterns of citizenship behavior and improvement of the environmental quality of habitation areas, it is important to explain the features and its associated effects on the physical role of cities in reduction of urban crime and offenses and lowering crime occurrences. This is described in new urbanism theories. Moreover, numerous studies have proved that by changing environmental conditions and proper space designing, the rate of special crime will reduce and on the other hand, it will increase safely level of the society. Nowadays, crime and violence are regarded as a part of public life which can lead to increased rates of crime and social problems and create significant problems for the cities. Due to these problems which mostly occur in man- made and physical environments of urban areas, implementation of proper urban planning and designing approach related to security and safety seems quite necessary. The concept of crime prevention through environmental design (CPTED) for such urban environment plays a crucial role in lessening the crime and violence. Taking advantage of CPTED environmental design, crime preventive strategies have become a branch of mechanical approaches used in prevention of crime. This emphasizes on the idea affecting the situational factors is much easier than changing it and fighting against human weaknesses and reforming criminals’ personalities. Hence, the perfect solution for crime prevention is limiting criminal opportunities.
Urban use with public performance has the highest rate of users in parks and recreational centers.  In other words, existence of parks among all classes of society is felt. It also has a privileged social position and its presence is valuable for all social classes, especially the low-income strata of society. Due to its high levels of users, the Mellat Park has become one of the most important recreational sites in the city. It has a better position relative to other parks of the city. Therefore, analysis and assessment of the safety level of the park is noteworthy. The main objective of this study is to identify the sites with low urban safety levels, especially those located in vulnerable places (children and women). The evaluation and implementation of CPTED strategies, discussed within the study, are along with safety assessment methodology as a new approach in evaluation and analysis of the rates of urban safety uses.
 
Methodology
This applied study has a descriptive- analytical method. Data collection was carried out by using two ways: documentary and field survey. In order to gather data and according to CPTED strategy and safety audit model, a questionnaire was prepared and the field survey of the research scope was prepared. In addition, to assess the lighting situation and safety level of the study area, the graphic statistical analysis software (Arc GIS, Excel) were used.
 
Results and Discussion
 According to field observations, most lightings installed in the park are 400-watt sodium vapor lamps with a 47,000 lumen luminous flux and the brightness on its side streets (the connecting park roads are considered as side streets) is 10 lux (equivalent to 8 m). Due to the height of power poles in the park, this size is not fixed. According to the brightness calculations of lighting for lampposts hung, a range of about 8 and 15 meters is considered as bright and semi- bright, respectively. For round lampposts also the rates of 5 and 12 m are considered. Finally, for 4 projectors available in the park, 20 m on the bright and semi- bright cases is taken into account. However, these rates are in accordance with the standard lighting calculations. Based on these rates of available light poles and light exposure within the park  assessed by Arc GIS software, it is indicated that the absolute darkness of the park area at night is more than 70%. According to the results of safety assessment and inspection of the site, it was realized that most lightening equipment of the park is from type B located on the sides of the connecting roads. The lights of type B are located just in two part of the park including within a large swimming pool and the entertainment park area. Thus, more than 80% of the park equipment is designed so inappropriately that they were contrary to the principles and strategies of crime prevention.
 
Conclusion
According to the studies conducted in the field of crime prevention, both foreign and domestic researches clearly represent the importance and usefulness of this approach in the field of prevention of crime and crime occurrence in all urban areas. The results of this analysis on this park indicate that it is very weak in terms of security. The results of the evaluation model of the Mellat Park in Zanjan show the inappropriate lighting and lighting equipment status in the site. Moreover, all lighting equipment is installed along the connecting paths so that the central areas of the park are left in darkness. This is due to the poor lightening design and lack of proper lampposts and lamps in the park. Therefore, it seems necessary to have  re-examination of its lighting and the resulting security problems of the park.