Modeling the causal loop diagram of the waste management cycle and providing a solution to organize the existing situation (Kerman case study)

Introduction: Organizing individuals who improperly conduct the separation and collection of valuable recyclable waste in urban areas has always been a fundamental challenge for municipalities. Various efforts have been made to regulate these individuals in Iran, but all have encountered failure. Almost all municipalities have accepted the presence of these individuals as an informal sector in urban waste management. The presence of an informal waste collection cycle in cities has always been associated with environmental, economic, social, and security problems and has consistently been a social and environmental challenge demanded by citizens. The purpose of this study is to establish a new financial structure in the form of operational licenses, to examine the informal flow of waste collectors in three scenarios using the Causal Loop Diagram (CLD) of waste management cycle modeled in Vensim software. The causal loop model developed in this research provides a new and complete understanding of stakeholders, variables influencing cooperation and competition among formal and informal actors in the waste management cycle of Kerman city.
Materials and methods: To simulate the performance of different scenarios of financial license pricing, concepts of systems thinking, dynamic planning, and the CLD model in Vensim software have been utilized. The causal loop diagram of waste management cycle has been analyzed based on field statistical data. Identifying and collecting information from informal actors has faced challenges due to the opaque and sometimes law-evading nature of their activities. To collect information related to these actors, field methods including semi-structured interviews with samples of these activists as well as consultations from experts and city officials have been used. The current state of the formal and informal waste management cycle has been examined and compared for three scenarios based on the conditions and infrastructure of the city of Kerman, with basic license prices of 500,000 and 1,000,000 tomans.
Results and discussion: At first, the CLD model of the waste cycle in Kerman City was drawn and analyzed using local conditions, the infrastructures of Kerman Municipality, and the behavior of actors in collecting recyclable waste. The drawing model was developed in Vensim software based on the collected field data and statistics from 2021 to 2022. The new scenario was defined based on the use of financial licenses to organize the informal collectors of recycled waste and separation from the origin of the definition and the assumptions of the model. Three scenarios of the existing situation, the basic license price of 500000 and 1000000 Tomans were examined and compared with each other. According to the results, in scenario 2, the municipality's share of the recycling market has increased by about 204%, and the amount of the municipality's profit, including the amount of the license issuance along with the discount, has increased by 232%. In scenario 3, the municipality's share of the recycling market has increased by about 400% compared to the current situation, and compared to the second scenario, it has increased by 64%, and the amount of the municipality's profit has increased by 507% compared to the current situation.
Conclusion: Financial licenses in the field of municipal waste management have been used in their simplest form so far, which have been mostly ineffective. The use of smart financial and licensing systems based on field conditions, the dynamics of actors' behavior, and smart policies can be a suitable solution for organizing urban waste management, especially the informal waste collection fleet.