Inundación

Definition

Flood is usually used as a general term to describe the overflow of water from a stream channel into normally dry land in the floodplain (riverine flooding), higher-than–normal levels along the coast and in lakes or reservoirs (coastal flooding) as well as ponding of water at or near the point where the rain fell (flash floods) (IRDR Glossary).

Facts and figures

Floods are the natural hazard with the highest frequency and the widest geographical distribution worldwide. According to the Organization for Economic Cooperation and Development (OECD)  flooding is one of the most common, widespread and destructive natural perils, affecting approximately 250 million people worldwide and causing more than $40 billion in damage and losses on an annual basis (OECD).

Flooding occurs most commonly from heavy rainfall when natural watercourses lack the capacity to convey excess water. It can also result from other phenomena, particularly in coastal areas, by a storm surge associated with a tropical cyclone, a tsunami or a high tide. Dam failure, triggered by an earthquake, for instance, will lead to flooding of the downstream area, even in dry weather conditions.

Various climatic and non-climatic processes can result in different types of floods: riverine floods, flash floods, urban floods, glacial lake outburst floods and coastal floods.

Flood magnitude depends on precipitation intensity, volume, timing and phase, from the antecedent conditions of rivers and the drainage basins (frozen or not or saturated soil moisture or unsaturated) and status. Climatological parameters that are likely to be affected by climate change are precipitation, windstorms, storm surges and sea-level rise (UNDRR).

When floodwaters recede, affected areas are often blanketed in silt and mud. The water and landscape can be contaminated with hazardous materials such as sharp debris, pesticides, fuel, and untreated sewage. Potentially dangerous mold blooms can quickly overwhelm water-soaked structures. Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks of deadly waterborne diseases like typhoid, hepatitis A, and cholera (UNDRR).

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    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.

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    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.

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    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...

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    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...

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    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...

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    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...

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    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...

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    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...

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    Floods and associated landslides account for the largest number of natural disasters and affect more people than any other type of natural disaster. With the availability of satellite rainfall analyses at fine time and space resolution, it has also become possible to mitigate such hazards on a near-global basis. In this article, a framework to detect floods and landslides related to heavy rain events in near-real-time is proposed. Key components of the framework are: a fine resolution precipitation acquisition system; a comprehensive land surface database; a hydrological modeling component; and landslide and debris flow model components. A key precipitation input dataset for the integrated applications is the NASA TRMM-based multi-satellite precipitation estimates. This dataset provides near real-time precipitation at a spatial-temporal resolution of 3 h and 0.258 x 0.258. In combination with global land surface datasets it is now possible to expand regional hazard...

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    Flooding is one of the most destructive natural hazards, accounting for over a third of all disaster damage worldwide. In particular inless developed countries (LDCs) this is typically attributed to poor planning, lack of warning systems and limited awareness of thehazard. A number of flood risk models have been developed, but have as yet contributed little to mapping and quantifying the risk inLDCs, for several reasons. In addition to limited human and technical capacity, these models require considerable amounts ofcurrent spatial information that is widely lacking, such as landcover, elevation and elements at risk basedata. Collecting those withground-based methods is difficult, but remote sensing technologies have the potential to acquire them economically. To account forthe variety of required information, data from different sensors are needed, some of which may not be available or affordable.Therefore, data interchangeability needs to be considered.Thus we test...

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