“…Use of crowdsourced photographs to detect flooding Witherow et al, 2018a,b Use of sensors in vehicles to detect flooding Wu and Wang, 2014;De Guzman et al, 2016;Amagsila et al, 2018 Social media such as Twitter Analysis of data from Twitter or similar social media data to detect flood events or map flood extent Holderness and Turpin, 2015;Kiatpanont et al, 2016;Pandey and Natarajan, 2016;Yadav and Rahman, 2016;Albahari and Schultz, 2017;Arthur et al, 2018;Feng and Sester, 2018;Lin et al, 2018;Yang et al, 2018;Bhuvaneswari and Valliyammai, 2019 Online reporting Use of online applications such as Ushahidi or bespoke applications to report flooding Koswatte et al, 2015Koswatte et al, , 2016Koswatte et al, , 2018Ludwig et al, 2015;Naik, 2016;Victorino et al, 2016;Pánek et al, 2017 Mobile apps Use of mobile apps to report flooding Liu et al, 2011;Victorino and Estuar, 2014;Le Coz et al, 2016;Victorino et al, 2016;Middelhoff et al, 2017;Minn et al, 2017;Sahay et al, 2017;Hendricks et al, 2018;Wang et al, 2018;Yabut et al, 2018 Kutija et al, 2014;Blumberg et al, 2015;Yu et al, 2016;Lewis and Silkstone, 2017;Loftis et al, 2017 Integrated systems − Systems for integrating sensors, authoritative data and crowdsourced data for flood management and early warning ...…”