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Therefore, more floods are largely the result of human activities, given the important land-cover transformations. For instance, deforested or urbanized areas are the physical and social factors that lead to the deterioration of watersheds and an increased vulnerability to intense rains. An increase in the number of floods in recent decades is more evident in the states close to the Gulf of Mexico, in the central Highlands including the Mexico City Metropolitan Areathe southern coast of the Mexican Pacific and parts of northern Mexico Fig.
This risk condition may set a value for a Flood Early Warning System to be implemented. Episodes of more than mm accumulated precipitation during three consecutive days were also used to characterize natural hazards that may result in floods.
The risk of flood is calculated as the product of the normalized values of the natural hazard P95 by the vulnerability index. Atlas Nacional De Riesgos Floods in Tabasco, Mexico: Land cover changes in small catchments in Slovakia during and their effects on frequency of flood events.
Conclusions and recommendations on flood-risk management are drawn in the diesgos part of this article. It would also be adequate to include the effect of sediments on riverbeds as a vulnerability factor, since it results in a lower streamflow capacity. In recent decades forty yearsthe number of floods in the state Guerrero have at least doubled. It may also serve to set vulnerability goals under climate change scenarios aiming at disaster prevention.
It is clear that the risk model may be improved by including additional elements in the vulnerability analyses. It can be described in terms of physical, social and economical factors. The vulnerability index between and shows the low-frequency modulating effect of flood risk. When this information is combined with a vulnerability estimate, those regions with a large probability of experiencing a flood are identified Fig. Therefore, a diagnosis of the major causes of this type of disaster should be determined, and a risk management strategy should be implemented if the social, economic and environmental costs of floods are to be reduced.
Journal of Geophysical Research: Changes in land cover are one of the most important drivers of water infiltration, runoff and sediment buildup in rivers, lakes and dams. Computers and Electronics in Agriculture37 1 Flood damage, vulnerability and risk perception-challenges for flood damage research. Data on the number of floods were obtained from two sources: Finally, the adequacy of the vulnerability and flood-risk estimates was obtained by comparing the spatial distribution of flood risk vs.
Part 3 details the methodology for flood-risk analysis. In this way, it is through the spatial and temporal comparison of risk and flood rirsgos that the adequacy of vulnerability can be evaluated, since there are no historical records of the magnitude of floods for a more quantitative assessment. Therefore, if increasing flood activity is to be explained, one must necessarily include the modulating effect of vulnerability.
The increased risk of floods due to deforestation for specific regions of Mexico where the hazard of intense rainfall associated with various phenomena has emerged, is illustrated below. A method for estimating volume and rate of runoff naciojal small watersheds. Journal of Flood Risk Management2 2 A proper identification of vulnerability is crucial if risk-reduction strategies aimed at diminishing disaster activity are the goal. Water in Mexico City: Therefore, risk quantification is necessary for developing risk management nacoonal, and vulnerability factors and indicators support actions that are deemed necessary to define efficient disaster prevention practices.
Infiltration capacity in scrubland and forests is higher than in grasslands, agricultural land or regions without vegetation. Floods are more frequent during the summer rainy season, as precipitation extremes are more common during this season of the year when the soil is wet, which makes it less permeable to rainfall. Related Articles
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