Preface: Remote Sensing in Flood Monitoring and Management

Abstract

This Special Issue is a collection of papers studying the use of remote sensing data and methods for flood monitoring and management. The articles contributed span a wide range of topics and present novel processing techniques, review methods and discuss limitations, and also report on current capabilities and outline emerging needs. This preface provides a brief overview of the content.Keywords: flood hazard and risk; satellite imagery; altimetry; digital elevation model; hydrodynamics ScopeFloods can be mapped and monitored with remotely sensed data acquired by aircraft and satellites, or even from ground-based platforms. The sensors and data processing techniques that exist to derive information about floods are numerous. Instruments that record flood events may operate in the visible, thermal and microwave range of the electromagnetic spectrum. Due to the limitations posed by adverse weather conditions during flood events, active radar is invaluable for monitoring floods; however, if a visible image of flooding can be acquired, retrieving useful information from this is often more straightforward.Apart from providing direct information about flooding, remote sensing data can also be integrated with flood models (via model calibration or validation, and data assimilation techniques) or provide floodplain topography data to augment the amount and type of information available for efficient flood management. There have been notable studies on integrating remotely sensed data with flood modeling since the late 1990s and there is now a general consensus among space agencies to strengthen the support that satellite missions can offer. This trend has stimulated more research in this area, and significant progress has been achieved in recent years in fostering our understanding of the ways in which remote sensing can support flood monitoring and management.This Special Issue presents a collection of work on current efforts to aid advancing flood monitoring and management through remotely sensed data. The following section gives a brief overview of the large variety of papers contributed to this Special Issue, presenting the use of remote sensing data and methods in flood research and applications. Overview of ContributionsThe variety of high quality research and application studies published in this Special Issue is large and I only provide a brief overview here. I encourage the reader to refer to the entire Special Issue to gain insight into the current state-of-the-art methods employed in remote sensing for flood monitoring and management.The contributed articles cover local to global scale applications and range across a number of fields (e.g., disaster management and societal impact, flood forecasting, rainfall-runoff modeling, A number of papers in this Special Issue also demonstrate that much is to be gained from combining satellite flood maps with digital elevation models (DEMs) and also distributed process models. Merging zonal flood information with topography can reveal complexities in water surf...

Automatic Estimation of Urban Waterlogging Depths from Video Images Based on Ubiquitous Reference Objects

“…Although the proposed method has lower accuracy than water level sensors, especially when waterlogging is shallow, it is very cheap and could have a wide monitoring coverage. The remote sensing method can monitor urban flooding with wide coverage [9]. However, remote sensing images are usually affected by weather and occlusion, and often have low spatiotemporal resolutions [3,9].…”

“…The remote sensing method can monitor urban flooding with wide coverage [9]. However, remote sensing images are usually affected by weather and occlusion, and often have low spatiotemporal resolutions [3,9]. Compared with the remote sensing method, this proposed method has higher spatiotemporal resolution and accuracy, and it is less prone to be affected by weather and occlusion, but monitoring coverage may be smaller due to the limitation of camera distributions.…”

“…Currently, there are four main types of data sources for urban flood depth extraction, including water level sensors [5], remote sensing [6][7][8][9], social-media/crowdsourcing data [3,10], and video surveillance data [4]. Among these data sources, video surveillance data can record the entire process of urban flooding and has the advantages of continuity in time, high resolution, wide coverage in space, and low cost, which makes it the most attractive data source.…”

Climate Change and Transport Infrastructures: State of the Art

“…Road corridors should be protected by engineered structures such as levees to prevent human and social risks. Instantaneous sea level monitoring by remote sensing and ground sensors are often installed to prevent the flooding risk [104,105].…”

Contributions of Operational Satellites in Monitoring the Catastrophic Floodwaters Due to Hurricane Harvey

“…Compared with high spatial resolution sensors, such as optical sensors like the Landsat and radar sensors, which usually offer a 6-16 day repeat cycle, operational satellites usually have relatively high temporal resolution, of twice per day for polar orbiting satellites and 5-30 min for operational geostationary satellites. As a flood is usually a short term event, operational satellites with large area coverage and frequent revisit, either used alone or in combination with other high spatial resolution sensors, or complemented by numerical model simulations, have played significant roles in the detection and monitoring of large floods [18][19][20][21]. For example, Schumann et al [18] demonstrated an application for the May-June 2015 Texas flood disaster using only satellite observations.…”