# A Review of Cutting-Edge Sensor Technologies for Improved Flood Monitoring and Damage Assessment
## 4 Global Applications of Flood Sensors  
Developed countries exhibit some differences from developing countries in terms of flood sensor technology and its applications. To preserve spatial variability and disregard the temporal stratification of event occurrence, we searched and filtered significant flood events with substantial mortality and economic loss during the same period in the EM-DAT database for comparison. We explored the link between the application of flood sensors and flood disaster losses to substantiate the importance of flood sensor development in flood management (Table 7). What is currently known is that developed countries have state-of-the-art hydrometeorological analysis and proximity forecasting products and use more advanced processing methods for flood data [128; 129]. Developing countries, on the other hand, generally have poor flood defense infrastructure [130], and citizen science has been proven, in practice, to be one of the most useful methodology applied to manage flood risk in the poorest, most vulnerable, and marginalized areas [131], but it has limited data volume, accuracy, and emergency response capacity, with the IAHS reporting that developing countries often suffer greater flood losses due to the inability to make accurate flood forecasts [132]. In addition, there was still a serious knowledge gap between developing and developed countries in terms of data utilization, potential, and challenges [133], with developed countries having a wider range of satellite research activities compared to developing countries [105], with timely access to a large amount of data through domestic space agencies, whereas, on the contrary, most developing countries have difficulty in accessing it from domestic sources [134] and there is a large time lag in obtaining satellite resources through open access, which affects the real-time monitoring and relief of floods. \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Data Type** & **Datasets** & **Content** \\ \hline \multirow{4}{*}{Multimodal Multimodal} & RAPID-NRT & Satellite imagery and ancillary data (topography data, water occurrence data, hydrography information, etc.) on flooding in the contiguous United States \\ \cline{2-3}  & MM-Flood & Satellite imagery of 95 flood events in 42 countries, as well as DEM and hydrological maps \\ \cline{2-3}  & Hurricane Harvey Floods & Rainfall data and flood impact data from Hurricane Harvey \\ \cline{2-3}  & California flood dataset & Satellite imagery, InSAR data, and optical data of flooding events in California \\ \cline{2-3}  & MSAW & Geospatial data including SAR and electro-optical images of the Rotterdam area in the Netherlands \\ \cline{2-3}  & WorldFloods dataset & Multimodal data, such as satellite imagery of 119 flood events between 2015 and 2019 \\ \cline{2-3}  & SIGFoods Dataset & Satellite imagery of 46 flood events between 2015 and 2022 \\ \cline{2-3}  & EU Flood Dataset & Information on more than 50 different data sources for hydrology \\ \cline{2-3}  & UNOSAT Flood Dataset & Flood extent data, historical flood data, population and crop exposure statistics, etc., for selected flood events since 2007 \\ \hline \multirow{4}{*}{Text-Image} & CEMS & Satellite images, meteorological data, etc. for near-real-time flood monitoring and forecasting \\ \cline{2-3}  & Global Flood Monitor & 88 million tweets about more than 10,000 flood events across 176 countries in 11 languages \\ \cline{2-3}  & CrisisMMD & Thousands of tweets and images collected during seven major natural disasters in 2017 \\ \cline{2-3}  & EM-DAT & Flood disaster records from 1900 to the present that meet the inclusion criteria \\ \hline \hline \end{tabular}
\end{table} 
Table 6: _Cont._Natural hazards such as flash floods, landslides, and mudslides are always frequent in developing countries around the Hindu Kush Himalayan (HKH) region [135], among which Pakistan suffers from floods almost every year.