Faculty of Management, Science and Technology, Open University of the Netherlands, Heerlen, The Netherlands.
Department of Environmental Sciences, Faculty of Science, Open University of the Netherlands, Heerlen, The Netherlands.
Waste Manag Res. 2022 Sep;40(9):1337-1355. doi: 10.1177/0734242X221074189. Epub 2022 Feb 8.
Cities in developing countries struggle with providing good waste collection services to all their citizens. Daily practice mostly shows low service coverage, especially in the poorer parts of cities. Up until now, research has mainly dealt with the symptoms of poor performance. This article aims at designing a qualitative System Dynamics model of the urban system that may serve as a diagnostic tool to find the root causes and leverage points for interventions. The research presented here uses a broad literature review to draw up a complex causal loop diagram describing all relevant urban variables (demographic, economic, social, financial, technical and governance-related) and their relations. The diagram is analysed using qualitative methods, partly derived from graph theory. It results in an evaluation of all variables, paths, loops and branches of the model, and finally in a simplified model. This simplified model is helpful in diagnosing waste management problems in cities, in formulating interventions and their points of leverage and even in formulating a new taxonomy that classifies cities with regard to the effect and delay in their urban processes. When it comes to interventions, the model suggests that the root cause is in populations growing faster than their economies, and that the enabling circumstances are mainly in poor governance practices that are unable to secure that tax incomes keep pace with needed budgets for sound services.
发展中国家的城市在为所有市民提供良好的废物收集服务方面存在困难。日常实践表明,服务覆盖面很低,特别是在城市较贫困的地区。到目前为止,研究主要针对绩效不佳的症状。本文旨在设计一个城市系统的定性系统动力学模型,作为一种诊断工具,以找到干预的根本原因和着力点。本研究通过广泛的文献回顾,绘制了一个复杂的因果回路图,描述了所有相关的城市变量(人口、经济、社会、财务、技术和治理相关)及其关系。该图使用定性方法进行分析,部分源自图论。这导致对模型的所有变量、路径、循环和分支进行评估,最终得到一个简化的模型。这个简化的模型有助于诊断城市的废物管理问题,制定干预措施及其着力点,甚至可以制定一种新的分类法,根据城市的进程效果和延迟来对城市进行分类。在干预方面,模型表明,根本原因是人口增长速度快于经济增长速度,而有利环境主要在于治理不善,无法确保税收收入跟上健全服务所需的预算。