Generation of and solutions to canal waste: a case study in Bangkok

抄録

Waste floating in canals or waterways (hereafter “canal waste”) is a source of environmental degradation and flood risk in many Southeast Asian cities. However, the issue has not yet been investigated in depth. The aims of this study were to clarify the mechanisms of canal waste generation and to propose potential solutions to the issue, based on a case study conducted in Bangkok, Thailand. We conducted field surveys in January 2018 and March 2019 to collect information regarding the system and resources in place to collect waste from residents near canals and local good practices to solve the issue of canal waste. The survey results were analyzed based on our assumption that unintentional dropping (fall) of waste occurs from settlements built above the canal or waste collection stations along the canal. The results suggested that direct causes of waste fall include natural phenomena (e.g., wind) and human error, while indirect causes include the use of poorly built living spaces above the canal, lack of collection capacity, insufficient waste bin capacity, and limited access to official collection points. Two types of potential solutions were proposed accordingly; to move the settlements from above the canal, and to increase land-based waste collection.