Early warning systems form an important element of disaster risk management. Compared to systems for flood forecasting, that assess risk, early warning systems sends out a warning either when a community is at risk from imminent flooding or when a flood event is already affecting a community. There are four key elements of an early warning system for floods; these include a) assessments of flood risks, b) monitoring of local hazards (forecasts) and warning service, c) dissemination of flood risk information, and d) building community response capabilities. 12 Warning systems can be incorporated into most existing communication infrastructures. This strategy is particularly valuable where protection through large scale, hard defenses, is not acquirable.1 Warning systems require constant monitoring and risk assessment.2 They are generally low-cost and have proven to be successful in numerous developed or developing countries.3

How it works

Types of warning system

  • Sensor Networks for Flood Detection are used for flood detection in areas that are affected by heavy rainfall and hurricanes.
  • In a Based and GIS-Based Flood, Warning data is collected in real-time from hydrological observation stations. The data is then processed by a centralized computer system and results are sent to a client computer in a control room via remote access.
  • Flood Warning based on Radio, SMS, TVs, and Phones use a microcontroller from the “ARM family, a Marvell 88F6281 and the Unix FreeBSD interface and integrated database.” Hydrological data is then sent in real-time for decision making via radio communication. 11


  • Provides a prediction of the scale, timing, location, and likely damage that might be caused by an impending flood
  • Provides timely notice for the release of gated dam water. This helps to, reduce damage to communities and ecosystems
  • Can serve as an adaptation measure at the individual and household level because data can be sent directly to individuals within a household.
  • When implemented at the local and regional scales, it can reach those groups that are especially vulnerable to flooding. 12
  • Helps to improve disaster preparedness and hence can significantly reduce expensive disaster relief efforts.


  • Success is dependent on public acceptance and participation
  • Can sometimes be easily ignored especially warning systems along highways
  • Flood warning efficiency and distribution could be reduced by limited access to communication networks, particularly in remote regions
  • False alarms could lead to uncertainty and hesitancy in future responses.
  • Availability and accessibility of good quality real-time data may be limited 12

Example projects

River Forecast Centre

BC, Canada

The River Forecast Centre is a live interactive platform used by the province of British Columbia to provide information on seasonal water supply and flood risk, and river and streams flow predictions within the region.8 The interactive platform allows emergency managers and the public to prepare and/or respond to bulletins, maps, and flood warnings.9 Flood warnings and advisory maps identify current and future conditions in major basins and sub-basins at different advisory and warning levels. The center also provides high streamflow advisories, flood watch, and flood warnings.10

Cyclone Warning System


Historically, Bangladesh has been an active area for tropical cyclones. Unfortunately, a lack of protective measures has resulted in high death and casualty rates.4 As an adaptation response, Bangladesh implemented the Cyclone Preparedness Programme (CPP) which focuses on infrastructure development, an early warning system, and cyclone shelters.5 The warning system consists of three components: monitoring, evaluation, and response and draws data from multiple sources.6 The warning system has proven to be successful during the 1970, 1991 and 2007 cyclones which resulted in fewer deaths.7


  1. 1.

    Zhu, Xianli, et al. Technologies for Climate Change Adaptation - Coastal Erosion and Flooding. 2010, pp. 92. https://orbit.dtu.dk/files/5699563/Technologies for Climate Change Adaptation-Coastal Erosion and Flooding.pdf.

  2. 2.

    Ibid, 92.

  3. 3.

    Ibid, 95-96.

  4. 4.

    Ibid, 99.

  5. 5.

    Ibid, 99.

  6. 6.

    Ibid, 99.

  7. 7.

    Ibid, 100.

  8. 8.

    Ministry of Forests Lands and Natural Resource Operations. “River Forecast Centre.” Province of British Columbia, Province of British Columbia, 14 May 2019, https://www2.gov.bc.ca/gov/content/environment/air-land-water/water/drought-flooding-dikes-dams/river-forecast-centre.

  9. 9.


  10. 10.


  11. 11.

    Keoduangsine, S., Goodwin, R., & Gardner-Stephen, P. (2014). A Review of Flood Warning Systems in Developed and Developing Countries. International Journal of Future Computer and Communication, 3(3), 172.

  12. 12.

    United Nations, DHI Centre of Water and Environment. (n.d). Early warning systems for floods. https://www.ctc-n.org/sites/www.ctc-n.org/files/resources/early_warning_systems_for_floods_0.pdf

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