Inundación

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...

Dhaka, the capital city of Bangladesh, is surrounded by distributaries of two major rivers, Brahmaputra and Meghna. The city has been subjected to periodic flooding since its early days due to these river system and low topography. Flooding of the city is mainly caused by spillover from surrounding rivers as well as internal water logging problems throughout of the city. Flood mitigation is an important issue in land use planning. Remote sensing could provide timely and low-cost information on floods and land use status whereas GIS is an excellent tool in handling information in land management and flood mitigation. This study was carried out to use remote sensing and GIS technologies to create flood vulnerability map of Dhaka city. Landsat TM data was used to generate a land cover, and JERS-SAR andADEOS-AVNIR 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...

Flood hazard maps were developed using remote sensing (RS) data for the historical event of the 1988 flood with data of elevation height, and geological and physiographic divisions. Flood damage depends on the hydraulic factors which include characteristics of the flood such as the depth of flooding, rate of the rise in water level, propagation of a flood wave, duration and frequency of flooding, sediment load, and timing. In this study flood depth and "flood-affected frequency" within one flood event were considered for the evaluation of flood hazard assessment, where the depth and frequency of the flooding were assumed to be the major determinant in estimating the total damage function. Different combinations of thematic maps among physiography, geology, land cover and elevation were evaluated for flood hazard maps and a best combination for the event of the 1988 flood was proposed. Finally, the flood hazard map for Bangladesh and a flood risk map for the...

Flood hazard maps were developed using remote sensing (RS) data for thehistorical event of the 1988 flood with data of elevation height, and geological andphysiographic divisions. Flood damage depends on the hydraulic factors whichinclude characteristics of the flood such as the depth of flooding, rate of the rise inwater level, propagation of a flood wave, duration and frequency of flooding,sediment load, and timing. In this study flood depth and "flood-affected frequency"within one flood event were considered for the evaluation of flood hazard assessment,where the depth and frequency of the flooding were assumed to be the majordeterminant in estimating the total damage function. Different combinations ofthematic maps among physiography, geology, land cover and elevation wereevaluated for flood hazard maps and a best combination for the event of the 1988flood was proposed. Finally, the flood hazard map for Bangladesh and a flood riskmap for the...

Floods are a common disaster in many parts of the world. It is considered to be the most common, costly and deadly of all natural hazards. Flooding is not just confined to certain region of the world but is a globally pervasive hazard. India experiences one of the highest incidences of Flood, and the area subjected to it is estimated to be one-eight of the geographical area (0.410 M km2) and have been occurring almost regularly each and every year.

Among the several states prone to flooding, Orissa state is one of them, which is mainly due to the existence of Mahanadi delta system. Studies have been carried out related to understand dynamic processes and the flooding problem in Mahanadi river system in the past. In this study, Daya river system, which is a part of Mahanadi Delta and which is one of the most flood prone areas in Orissa is selected. Heavy monsoon rainfall and congestion of drainage pattern in the river system are considered to be the main cause of...