A Review of Citizen Science and Crowdsourcing in Applications of Pluvial Flooding

Abstract

Pluvial flooding can have devastating effects, both in terms of loss of life and damage. Predicting pluvial floods is difficult and many cities do not have a hydrodynamic model or an early warning system in place. Citizen science and crowdsourcing have the potential for contributing to early warning systems (EWS) and can also provide data for validating flood forecasting models. Although there are increasing applications of citizen science and crowdsourcing in fluvial hydrology, less is known about activities related to pluvial flooding. Hence the aim of this paper is to review current activities in citizen science and crowdsourcing with respect to applications of pluvial flooding. Based on a search in Scopus, the papers were first filtered for relevant content and then classified into four main themes. The first two themes were divided into (i) applications relevant during a flood event, which includes automated street flooding detection using crowdsourced photographs and sensors, analysis of social media, and online and mobile applications for flood reporting; and (ii) applications related to post-flood events. The use of citizen science and crowdsourcing for model development and validation is the third theme while the development of integrated systems is theme four. All four main areas of research have the potential to contribute to EWS and build community resilience. Moreover, developments in one will benefit others, e.g., further developments in flood reporting applications and automated flood detection systems will yield data useful for model validation.

Reconstituting past flood events: the contribution of citizen science

“…Citizen science is a form of collaborative research involving citizens in scientific projects (Wiggins and Crowston, 2011). Citizen science has attracted much attention from scientists in many fields such as ecology (Dickinson et al, 2010;Silvertown, 2009), astronomy (Raddick et al, 2007) and more recently hydrology (Buytaert et al, 2014;Paul et al, 2018). Rapid advancements in various modern technologies -the internet, web 2.0, virtual globe, location-based services, social media, mobile devices, interactive geo-visualisation interfaces such as OpenStreetMap, Google Earth and Geo-Wiki (Fritz et al, 2009;Mooney and Minghini, 2017;Yu and Gong, 2012) -as well as the rise of participatory research characterised by greater user interactivity and collaboration, have increased the number of studies and subjects investigated by citizen science projects.…”

“…Assumpção et al (2018) focused on the role citizen science could play in flood modelling and demonstrated its value to provide data for informing, calibrating and validating flood models, particularly where data are scare. It is notable that most of the existing studies have dealt with fluvial flooding; fewer studies have considered pluvial or groundwater flooding (See, 2019). Moreover, none of those citizen science projects have studied the reconstruction of past events using citizen memory, unlike the field of wildlife conservation where Zhang et al (2018) demonstrated the value of citizen data for mapping past phenomena that were not otherwise recorded.…”

Quantifying Flood Water Levels Using Image-Based Volunteered Geographic Information

“…Most feasible image-based VGI properties in the aforementioned studies were used for land cover and change identification. In addition, scales of detected objects such as flooding areas and heights are expected be quantified through spatial computation of image-based VGI and three-dimensional spatial information; however, VGI studies still face challenges, which include exploring the use of image-based VGI as data interpreters; improving methods to estimate water level from images; and harmonizing the time frequency and spatial distribution of models with those of crowdsourced data [31,32]. Rosser et al mentioned that, when image-based VGI, hydrological monitoring data and flooding simulations are integrated to estimate flooding extents, the accuracy of calculation is affected by the resolution of the terrain model [33].…”

Exploring the application of topographic indices in urban areas as indicators of pluvial flooding locations

“…In particular, citizen science and crowdsourcing using photographs, 311 municipal information services, phone applications, and social media have all been used during and after flood events to monitor the presence of urban nuisance flooding (See, 2019). In recent years, potential sources of data on urban flooding incidence have diversified and improved.…”

“…In recent years, potential sources of data on urban flooding incidence have diversified and improved. In particular, citizen science and crowdsourcing using photographs, 311 municipal information services, phone applications, and social media have all been used during and after flood events to monitor the presence of urban nuisance flooding (See, 2019).…”