Abstract
Flooding of transportation infrastructure triggers cascading indirect losses throughout supply chains and economies. When floods cause disruptions to rail infrastructure, numerous sectors are affected by lack of cargo movement. In regions with challenging topographies, railway lines often follow river contours to take advantage of the gradual slopes. This alignment, however, makes railways susceptible to flooding and operational disruptions. South Africa has been impacted by flooding events in recent years, and the national adaptation scenario program predict more frequent flooding events in the future due to change in climate. Railway operators fall behind on flood damage mitigation plans due to reliance on outdated inspections, lack of funding, less maintenance, poor observations and detection systems. The use of wired sensor system has been historically common for large deployment; however, their cost and difficult installation process has created gaps in effective weather monitoring programs. Aging infrastructure, theft and vandalism are other factors that hinder an effective flood monitoring program.
Wireless Sensor Networks (WSN) are an innovative technology that plays a crucial role in environmental monitoring and infrastructure maintenance. This research explores the existing wireless sensing technology with early warning capabilities worldwide, and review how railway operators can integrate both existing sensor network and modular systems into existing infrastructure. Literature review revealed characteristics and requirements of an effective WSN-based EWS, with case studies discussing different types of monitoring systems in various settings. The literature revealed themes in a form of features and operational requirements for a reliable early warning flood detection system. These themes included Connectivity, reliability, Power supply, scalability and weatherproofing, and were used as framework to analyse current South African documents related to flood monitoring initiatives. A qualitative research design was adopted, employing secondary document analysis of the selected documents. The research aims to provide railway operators and policymakers with a structured evaluation framework and evidence to guide investment decisions on WSN-based early warning systems.