Dear Colleagues,

Earth Observation (EO) has become a major tool for the study, monitoring, and management of natural hazards and disasters. In developing countries, EO is sometimes the only solution available to get quantitative measurements. Remote sensing is increasingly used by scientists, local authorities, NGOs, and disaster responders to answer their needs in spatial information for each stage of risk management, from hazard and vulnerability assessment to disaster monitoring and response. Complementary to ground information, satellite- and drone-based sensors help to get observations and measurements at different spatial and temporal scales, and sometimes in difficult-to-access areas, providing key intel for decision-making and field action.

Geohazards, i.e., natural hazards of geological or geophysical origin, are also increasingly being studied by remote sensing, as is the vulnerability of populations and infrastructure to these hazards. Earth observation tools now offer a growing range of techniques for quantifying risks in addition to their evaluation alone. In this respect, the challenges that remote sensing faces today concern both the coverage and spatial resolution as well as the temporal frequency of observations. Indeed, geohazards such as volcanic eruptions, landslides, earthquakes or tsunamis, for example, are often sporadic natural events that occur over a relatively short period of time and at scales ranging from a few square kilometers to hundreds or even thousands of square kilometers. In addition, difficult atmospheric conditions often require the use of a combination of sensors working in appropriate spectral bands, from visible to microwave.

During the past decade, new series of sensors and platforms have become real game-changers by providing both high-temporal and high-spatial resolution at the same time, and/or more sensitive sensors with a better signal-to-noise ratio. This has been possible thanks to the technological progress in spatial and sensor engineering, the recent advances in computer data processing and storage, the increasing number of available satellites and sensors, the development of satellite constellations, and the emergence of the unmanned aerial systems (UAS) for civil applications. In addition, free access to remote sensing data for scientific research is an increasing trend, which promotes the use of EO. The European initiative Copernicus satellite missions, with the new Sentinel constellations, the constellations of >190 micro-satellites developed by Planet Labs, and the increasing performance and decreasing cost of UAS applications are among these game changers that make EO more efficient and exploited every day.

In the present Special Issue, we welcome all publications related to the innovative use of recent sensors and algorithms in order to improve geohazard, vulnerability and risk assessment, as well as monitoring and disaster response. Both methodological and application papers are accepted. Satellite- and drone-based remote sensing are the main targets, but ground-based remote sensing is also very welcome.

In particular, research papers are encouraged to cover a wide range of subjects related to geohazards, vulnerability, and risk studies, which may include but are not limited to the following topics:

• Improvements provided by new algorithms, sensors, and constellations of satellites;
• Fundamental natural processes controlling the occurrence of geohazards;
• Mapping, monitoring and forecasting of geohazards;
• EO approaches for vulnerability and risk assessment;
• EO as a tool for disaster response;
• Innovative multisensor approaches;
• Innovative UAS applications;
• Time-series analysis using high spatial resolution imagery.

Dr. François Kervyn
Dr. Benoît Smets
Dr. Thomas J.B. Dewez
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Remote Sensing is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• Earth observation
• Geohazards
• Vulnerability
• Risk mitigation
• Disaster response