Flood

The use of Earth Observation techniques in the context of hazard management issues has received growing importance in recent years. Due to global climate change the scientific community foresees an increase in the intensity and frequency of extreme weather events, such as hurricanes, floods and windstorms. Specifically, floods already results in estimates of up to 25,000 annual deaths worldwide, extensive homelessness, disaster-induced disease, crop and livestock damage and other serious harm. The nearly allweather capacity constitutes the main advantage of SAR data above optical systems for mapping of flood events. The high resolution, the multi-polarization and multi-incidence angle capability of TerraSAR-X, its quick site access and receiving times open very interesting perspectives for flood mapping, assessment of damages after a hazard. TerraSAR-X data, coupled with the use of optical data and auxiliary data allows getting one step further in the development of…

A proto-type space-based disaster management system (DMS) has been organized with comprehensive database design, space-based near real-time monitoring/mapping tools, modelling framework, networking solutions and multi-agency interfaces. With the appropriate synthesis of these core elements, a system-definition of the frame-work of a DMS has been arrived at, in terms of developing a methodology towards damage assessment due to 1998 Brahmaputra floods. The limited validation experiments carried out in consultation with local level functionaries reveal that the experimental results on damage to agricultural crops due to floods are in conformity with field conditions. Still, there is a gap existing between the estimates arrived at and the estimates derived from conventional methods. It is herein that a concerted effort towards achieving absolute accuracy is called for. The conceived DMS ultimately aims at providing a holistic design and development of an information system…

Flooding happens mostly over the coastal region or low-lying land. It threatens the life of inhabitants, in addition to their property losses. Usually, the boundary of flooded region is determined with on site investigation, which is very difficult during flooding and even endangers the safety of field investigators. For a case of major flooding, on site investigation may take too many human and material resources before timely completion. Therefore, satellite remote sensing is a potential alternative for a fast and large-scale survey of flood region.

This study of delimiting the flood extent is through analyzing satellite images that were taken at different dates. For the case of flooding at Gangshan area after the typhoon Doug, we compared the satellite analysis against on site investigation and found that the extent of flooding matches each other. This result proves that satellite remote sensing is a viable method for quickly delimiting the extent of flooding…

In the immediate aftermath of Hurricane Katrina, remote sensing technology played a key role in assessing urban damage caused by windstorm, flood and storm surge. This paper provides an overview of techniques employed operationally damage assessment, presenting them within a spatially-tiered reconnaissance framework. Successfully implemented following disasters including the 2003 Bam earthquake and the 2004 Indian Ocean tsunami, the tiered reconnaissance system provides a theoretical framework for evaluating damage at regional (Tier 1), neighborhood (Tier 2) and per-building (Tier 3) scales. In the case of hurricane Katrina, regional activities included the acquisition and interpretation of PDV footage to provide near real-time multi-hazard impact assessments, and the use of Landsat to evaluate flood extent. At a neighborhood scale, NOAA aerial imagery was used to provide a severity ranking of wind damage and to assess storm surge effects along the Mississippi coast,…

Nepal, occupying the central part of the Hindu-Kush Himalayan belt covers an area of 147,181 square kilometers between India and China.About 6000 rivers and rivulets drain Nepal. Rugged topography, young geology and monsoon climate, all combine to produce high rate of runoff,erosion and sedimentation rendering the country highly vulnerable to water induced disasters and flood is one of the main recurring natural hazards. The Terai (plain area in the southern part) amounting to only 17% of the total area of the country is regarded as the granary of Nepal and the problems of flooding in this region are of utmost concern.The objective of this study is to integrate flood simulation model and remote sensing (RS) data with the available topographic and socioeconomic data in a geographic information system (GIS) environment for flood hazard mapping of Bagmati River in Terai region. Hydrologic model in combination with digital elevation model (DEM) is useful in delineating the…

Bangladesh suffered damage on account of the most catastrophic floods of 1987, 1988 and 1998, resulting in untold suffering of the people. This paper demonstrates the technique to develop a flood hazard map and a land development priority map for countermeasure against flood damage. To create the final products, flood hazard map and land development priority map, National Oceanographic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data for the flood events of 1988, 1995 and 1998 were incorporated with Geographical Information System data of physiographic divisions, geologic divisions, land cover classification, elevation height, drainage network, administrative districts and population density. Flood-affected frequency and flood depth categories were estimated using NOAA AVHRR images. Special attention was paid to population density for the construction of the land development priority map, because highly dense populated areas…

There has been increasing concern among the government officials who deal with emergency preparedness and natural disasters that increasing urbanisation is enhancing the risk from river flooding in urban areas. This study concerns such a risk for the City of London in the province of Ontario in Canada. It has been shown that between 1974 and 2000 there has been a considerably elevated risk from floods due to heavy urbanisation in the watershed of the Upper Thames River, of which the City of London is a part. Databases were prepared making use of satellite remote sensing technology on landuse classification and this information was integrated with meteorological and hydrological data records and analysed to obtain a quantitative estimate of the potential risk from river floods to London.

Much attention has been given to mapping the extent of a flood by using optical, radar, digital elevation model (DEM), and river gauge data. The mapped extent is often supported and verified by ground observations. The popularity of methods that use these data sets has arisen due to effectiveness, availability, and low cost. This paper summarizes the strengths and weaknesses of the individual and combined use of optical, radar, DEM, and river gauge data to map flood extent. The 1999 flood associated with Hurricane Floyd in eastern North Carolina is used as an example throughout the paper.

There are several natural disasters occurring throughout the world round the year and causing huge loss to the lives, property and natural resources. Assessment of damage caused by these disasters needs to be carried out accurately in minimum possible time frame. Space technology is one of the best-suited means for the assessment of damage brought about by natural disasters. Remote sensing satellites provide synoptic view, repetitive coverage and high-resolution images. This advanced high-resolution sensor technology has provided immense scope to the earth resource scientists world-wide for mapping and analysis of earth surface feature details using Remote Sensing and Geographic Information System (RS & GIS). India is among several countries in the world, which face severe problem of floods every year particularly in the river basin of Ganga-Brahmaputra.

Considering the seriousness of the flood problem, Department of Space / Govt. of India…

Munshiganj district is situated on the mixed floodplains of rivers the Ganges (Padma), the Brahmaputra (Jamuna), and the Meghna. Every year even during normal rainy season floodwater drains through bordering rivers of the area to the Bay of Bengal. Most of the severe floods affect the area and cause maximum damages to the lives and properties in comparison to other areas. On the other hand, the area is densely populated and the number is rapidly increasing rising the number of people at risk.This study was carried out to create flood vulnerability map of Munshiganj district using satellite and GIS techniques. Landsat TM data was used to generate a land cover, and JERS-SAR and RADASAT data were combined to map flooded area in a normal flood event. Combining them with population data a population distribution map was produced according to land usetypes. Subsequently, this outcome was compared with flooded area mapped using satellite data in creating population that is at…