Abstract

Extended Abstract
Background and Purpose: In recent years, attention to the informal settlements and converting the decline cycle covers are changed into a serious and central subject. The organizations and scientific communities are cuased to struggle with the regeneration and organization of these urban textures. In the present approach, public space quality upgrading of these neighbors has a position because the indexes reduction of public spaces quality is one of the biggest dilemmas. This research assesses the relationship between the improvement of public space sustainability criteria and the Neighborhood Urban Regeneration plan in the context of informal settlements, offering a theoretical model composed of the indexes and criteria to obtain sustainable public open spaces in the case study. 
Materials and Methods: The present study is a descriptive-analytical survey. In the first part of the research, researchers use library tools to study documents and theoretical foundations to explore and identify environmental quality indicators and then extract desired behavioral patterns in open spaces. The method of evaluating the questions of the questionnaire was based on a 5-point Likert scale method designed based on Cochran's formula. 368 samples from a total of 9012 people in the neighborhood were selected as a statistical sample. 60 percent of the respondents are men, and the rest are women. The results indicate, that there is a significant relationship between criteria and indicators located in the model of measuring public open spaces with dependent variables of environmental sustainability (p_value <0.05).
Findings and Discussion: Public open spaces in inefficient informal neighborhoods give people the chance to socialize with other groups and connect to the city at the top of tensions and bottlenecks in the Living environment. This study has shown that the indicators of "comfort, convenience and sociability", "interior and exterior accessibility of spaces", "beauty and landscape of spaces" and "ability to perform activities" are the items that should be the focus of public space sustainability programs Occupy informal settlements and low-income urban neighborhoods. The results also showed that in the sample of research, increasing the ability to carry out activities, the amount of internal and external access to spaces, the sociability of spaces, and ultimately improving the beauty and landscape quality of public open spaces in the upper fence neighborhood, respectively the public open spaces of the neighborhood are from the perspective of its residents. Therefore, paying attention to providing superior qualities of public spaces based on needs assessment and preferences of space users is an important issue that experts should not neglect.
Conclusion: The results of statistical studies indicate that the public open spaces of the neighborhood suffer from low levels of environmental quality. According to statistical analysis of neighborhood residents, the level of user stability and activity, accessibility, comfort and sociability, and finally, the landscape spaces. The public opening should be a priority on the agenda of Karaj city management to organize these spaces. In addition, creating mixing and usefulness in uses, functional compatibility, enhancing comfort and convenience in The behavioral hangouts, strengthening environmental safety, and organizing the mental landscape, are one of the most important strategies for taking future measures to organize public open spaces in the Hesar Bala neighborhood.