Analysis of floods using satellite images - case study of the 2007 torrential flood in the Selška valley

An application of data mining for the determination of flooded areas was published in the Journal Geodetski vestnik (no. 54/2010-4). This paper analyses the usefulness of these results for further analyses of hydraulic parameters. The velocity and discharges were computed for six locations. The study showed that the flooded areas determined by satellite images can be used for further analyses. Nevertheless, other layers have to be sufficiently precise, especially the digital terrain model (DTM). DTM 12.5 was used. The study showed that DTM 12.5 is not precise enough. The observed area is very rough and the hydraulic parameters (cross sectional area of flow, wetted perimeter, hydraulic radius, river-bottom slope, flow velocity, discharge) cannot be detected with sufficient precision. Consequently the calculated hydraulic radiuses, velocities and discharges are out of expectations. In the first part of the article, some basic information about remote sensing and its techniques is presented. Some practical examples of their usage (especially satellite images) for the observation of natural disasters are also given

The use of satellite remote sensing for flood risk management

Over the last decades the impact of natural disasters to the global environment is becoming more and more severe. The number of disasters has dramatically increased, as well as the cost to the global economy and the number of people affected. Among the natural disaster, flood catastrophes are considered to be the most costly, devastating, broad extent and frequent, because of the tremendous fatalities, injuries, property damage, economic and social disruption they cause to the humankind. In the last thirty years, the World has suffered from severe flooding and the huge impact of floods has caused hundreds of thousands of deaths, destruction of infrastructures, disruption of economic activity and the loss of property for worth billions of dollars. In this context, satellite remote sensing, along with Geographic Information Systems (GIS), has become a key tool in flood risk management analysis. Remote sensing for supporting various aspects of flood risk management was investigated in the present thesis. In particular, the research focused on the use of satellite images for flood mapping and monitoring, damage assessment and risk assessment. The contribution of satellite remote sensing for the delineation of flood prone zones, the identification of damaged areas and the development of hazard maps was explored referring to selected cases of study