Funcionalidad familiar y satisfacción con la vida post desastre natural en una comunidad de San Antonio del Pedregal, Perú

Natural disasters, apart from economic losses, can also affect family functioning and life satisfaction due to the adverse events that are experienced. Therefore, the main purpose of the research was to know the relation between the family functionality and satisfaction with life in the community of San Antonio del Pedregal - Sector 1 in Lurigancho-Chosica, Peru; one of the geographical areas most affected by the presence of huaicos (frequent large floods in the Andean highlands) since the 1980s and that has recently experienced the adverse effects of the El Niño phenomenon of 2017. The research was correlational and transversal; furthermore, the study sample consisted of 180 local people. The results indicate that, despite the events experienced, people show moderate family functioning and are satisfied with their life. Women had a higher score in both variables compared to men, those over 60 years of age reported greater family functionality, and those under 30 years of age showed better results in life satisfaction.

Japanese Hops (Humulus japonicus) Control and Management Strategies in Large River Floodplains

Japanese hops (Humulus japonicus) is an invasive vine that establishes in open areas in riverine habitats and suppresses tree regeneration and native vegetation. This study evaluated the use of herbicides and tree plantings to control and manage Japanese hops on five Mississippi River islands over a four-year period. Herbicide treatments included a preemergent (sulfometuron methyl), a postemergent (glyphosate), and a combination of both. Tree plantings used containerized and bareroot American sycamore (Platanus occidentalis) and eastern cottonwood (Populus deltoides) trees. Japanese hops biomass was significantly lower in all herbicide treatments in 2012 and 2015, but the preemergent treatment was less effective than other treatments in 2012 and 2014. After two years, average survivorship of containerized trees was 20%–42%, whereas bareroot seedlings had near 100% mortality. Results indicate that postemergent treatments are effective for short-term control, but large floods reestablish Japanese hops in treated areas. Reforestation, if combined with herbicide treatments and active management, may be a promising approach in large river floodplains that experience frequent flooding, but low tree survivorship presents challenges to reforestation. Study Implications Japanese hops (Humulus japonicus) is an invasive vine that establishes in open riparian areas and suppresses tree regeneration and other native vegetation. We confirmed that glyphosate provides effective short-term control, but also found that large floods can quickly reestablish Japanese hops in treated areas. Bareroot seedling mortality was extremely high, but initial survival and growth rates of containerized trees were more promising. We conclude that tree plantings combined with active maintenance, including glyphosate application, may be a viable option for long-term control of Japanese hops in upper Mississippi River floodplains.

Flood hydrometeorological situations associated with monsoon floods on the Par River in Western India

The objective of present work is to understand flood hydrometeorological situations associated with monsoon floods on the Par River, therefore, the analyses of synoptic conditions connected with large floods was carried out. This encompasses analysis of interannual rainfall variability and associated floods, analysis of storm tracts, investigation of normalized accumulated departure from mean (NADM) and evaluation of the relation between El Niño and monsoon rainfall. In order to accomplish above analyses, the annual rainfall data of the Par Basin have been obtained for 118 years from India Meteorological Department (IMD), Pune and Chennai. The annual maximum series (AMS)/stage data were procured for a gauging site namely Nanivahial for 45 years from Irrigation Department of Gujarat State, Ahmedabad. The results indicate that the interannual variability was characterized by increased frequency and magnitude of floods on the Par River primarily after 1930s. Majority of the large floods in the basin were connected with low pressure systems. It is observed that most of the floods were associated with positive departure from mean rainfall in the basin. The NADM graph shows epochal behaviour of high and low rainfall of the basin and floods. The analysis of El Niño and Southern Oscillation indicates that the probability of the occurrence of the floods in the Par Basin is high during the average SST index and majority of the floods in the basin have occurred during above normal conditions of rainfall. The present study can, therefore, prove to be a significant contribution towards the Par-Tapi-Narmada link project of the Government of Gujarat and water divergent projects of the Government of Maharashtra in association with Government of India.

Sediment Regimes in South Korea

This study provides a comprehensive review of the existing river measurement data of South Korea. The specific sediment yield in the country is 5–1,500 tons/km ·year. The watershed area decisively affects the shapes of the curves for flow duration, sediment rating, and cumulative distribution of water and sediment discharge, and it can determine the effects of topographic and anthropogenic characteristics on erosion and sedimentation processes. Regarding flow regime, small watersheds have flashy hydrographs and high sediment concentrations at a given flow discharge. The coefficient of the sediment rating curves for various rivers decreases from 1 to 0.02 as the watershed area increases from 100 to 20,000 km , with the exponent of the curves ranging from 1.5 to 2.0. Moreover, sediment transport in small watersheds depends on large floods. The half-yield discharge typically ranges from 5 to 40 times the mean discharge, and it decreases with increasing watershed area. This study proposes equations to calculate the annual discharges, flow duration curves, sediment yield, and cumulative distribution curves of the flow and sediment, as well as the sediment yield at reservoirs in South Korea. Additionally, the sediment regimes in the country are compared to those in other continental regions.

Statistical analysis of maximum runoff of the Southern Buh River using the method of ‘Indicators of Hydrologic Alteration’

Knowledge of maximum river runoff trends is of great practical importance, especially for design and operation of hydraulic structures. This article presents the results of the research of the Southern Buh River's maximum runoff. The water of the river is widely used for hydropower engineering, industrial and municipal water supply, agriculture, irrigation, shipping, tourism etc. The research of the maximum runoff was based on the Indicators of Hydrologic Alteration (IHA) method which is widely used in the whole world. This method enables calculation of quantitative statistical characteristics of rivers', lakes', reservoirs' runoff and determination of the degree of their hydrological regime changes. The IHA is used for water bodies having natural or regulated runoff. However, the IHA method was not widely used in Ukraine before. The purpose of this publication is using the Indicators of Hydrologic Alterations method in order to study the characteristics of maximum runoff and their changes along the Southern Buh River. The research was carried out based on the data of observations at 5 gauge stations located along the Southern Buh River. The research uses the mean daily discharges that has been recorded since the beginning of observations up to 2018 and 2019 inclusive. The river's runoff at each of gauge stations was divided into five components: "Extremely low runoff", "Low runoff", "High runoff pulses", "Small floods", "Large floods". This made it possible to separate three classes of high (maximum) runoff, for which the IHA statistics were calculated, from the total runoff. It was discovered that the long-term high runoff changes differed in each of its three components, although they had general trends. The most significant changes were found for large floods, with no significant changes found for high runoff pulses. General trends of high runoff showed that over time the values of maximum discharges tend to decrease, with the increasing duration of high runoff periods. The values of the main statistical indicators of high runoff gradually increase from the river's source to its mouth, which fully corresponds to the physical and geographical conditions of its formation. Nevertheless, some features of high runoff were still found. Thus small floods and high runoff pulses have the largest duration in the upper reach of the river. On average, the Southern Buh River experiences large floods once in every 10 years, small floods - once in every 2 years, high runoff pulses - 4-8 times a year in its upper reach and 9-14 times a year in its middle reach.

Do small and large floods have the same drivers of change? A regional attribution analysis in Europe

Recent studies have shown evidence of increasing and decreasing trends for average floods and flood quantiles across Europe. Studies attributing observed changes in flood peaks to their drivers have mostly focused on the average flood behaviour, without distinguishing small and large floods. This paper proposes a new framework for attributing flood changes to potential drivers, as a function of return period (T), in a regional context. We assume flood peaks to follow a non-stationary regional Gumbel distribution, where the median flood and the 100-year growth factor are used as parameters. They are allowed to vary in time and between catchments as a function of the drivers quantified by covariates. The elasticities of floods with respect to the drivers and the contributions of the drivers to flood changes are estimated by Bayesian inference. The prior distributions of the elasticities of flood quantiles to the drivers are estimated by hydrological reasoning and from the literature. The attribution model is applied to European flood and covariate data and aims at attributing the observed flood trend patterns to specific drivers for different return periods at the regional scale. We analyse flood discharge records from 2370 hydrometric stations in Europe over the period 1960–2010. Extreme precipitation, antecedent soil moisture and snowmelt are the potential drivers of flood change considered in this study. Results show that, in northwestern Europe, extreme precipitation mainly contributes to changes in both the median (q2) and 100-year flood (q100), while the contributions of antecedent soil moisture are of secondary importance. In southern Europe, both antecedent soil moisture and extreme precipitation contribute to flood changes, and their relative importance depends on the return period. Antecedent soil moisture is the main contributor to changes in q2, while the contributions of the two drivers to changes in larger floods (T>10 years) are comparable. In eastern Europe, snowmelt drives changes in both q2 and q100.

Event indicator analysis using depth functions to explain the occurrence of large floods in Germany

<p>Large floods occur due to particular hydrometeorological conditions and could be characterized by different event indicators. By analyzing a large set of catchments and different events, the drivers of large flood peaks remain unclear. In addition to precipitation, also the prevailing situation in the catchment such as soil moisture conditions could control the occurrence of large floods.In this study, we analyzed a set of event indicators ranging from event precipitation via antecedent catchment state to catchment response for 169 gauges in Germany. For each gauge with a length of at least 50 years of daily observations, we derived the POT5 series. In order to test whether floods are characterized with unusual values of event indicators, we used the Tukey’s depth function. In this multivariate data analysis technique, a point cloud of different event indicators is subdivided at each point with a line into two groups. The depth value is hereby the minimum value of points in these two groups. This multivariate statistical method allows to find points in the center of the set, and those on or close to the boundary. Hence, points in the cloud center have high depth and correspond to ordinary values of the event indicators. Points at the edges of the cloud have low depth and indicate unusual indicator values. In case of low depth, the related event indicators can potentially be seen as drivers of these flood events. We compared all combinations of the event indicators with 2, 3 and 4 variables and analyzed which event indicators might cause the occurrence of large flood peaks.Our results show that the depth is reduced with increasing flood magnitude. Large floods are thus more unusual in terms of event indicators compared to smaller floods. The most relevant event indicators are maximum event precipitation and event precipitation volume. At least one of these indicators is required to explain the flood peak magnitude, but in most of the cases these two indicators are not sufficient. Inclusion of antecedent catchment state or a catchment response indicator improves the explanation in several but not all cases.Overall, we conclude that flood peak magnitudes at a specific catchment in our study region are mainly driven by the individual event characteristics. In most of the cases they cannot not be explained by typical patterns of event indicators for all large events at a given gauge.</p>

A Budyko-like framework for exploring the controls of long-term flood risk in coupled human-flood systems

<p>Long term dynamics in human-flood systems differ due to differences in hydrological and societal characteristics. By contrasting and comparing different human-flood systems we increase our understanding of which characteristics lead to which dynamics, which might help to counteract unfavorable developments. We propose a framework for comparing human-flood systems analogous to the Budyko one for traditional catchment hydrology. While in the Budyko framework catchments are classified as either water limited or energy limited, in the framework proposed here the human-flood systems are classified as either hydrology limited or exposure limited. In analogy to the precipitation, potential evapotranspiration and actual evapotranspiration components of the Budyko space we formulate the components of the “flood risk space” as hydrological potential loss, manmade potential loss and actual flood loss. The framework is applied to four stylised theoretical systems, investigating how their position in the flood risk space may change under the influence of hydrological, technical and demographic changes. Results show that hydrological changes have the largest effect on a system’s position in the flood risk space: with an increasing skewness and CV systems become more hydrology limited. The framework’s value for comparing empirical case studies is demonstrated through an application to two case studies in Germany: Dresden on the Elbe and Cologne on the Rhine. The framework allows us to identify the differences in dynamics between the two case studies, as they are located in different areas of the flood risk space. The difference in dynamics between the Dresden and Cologne systems seems to be mostly caused by the hydrological parameters (i.e. the skewness) rather than the social parameters. The flood frequency distribution is more skewed in the case of the Elbe in Dresden than in the case of the Rhine in Cologne. Therefore, Dresden experiences more shocks to the system (i.e. unexpectedly large floods) than Cologne.</p>

Data-based attribution of changes in flood quantiles across Europe between 1960 and 2010

<p>Changes in European floods during past decades have been analysed and detected by several studies. These studies typically focused on the mean flood behaviour, without distinguishing small and large floods. In this work, we investigate the causes of the detected flood trends across Europe over five decades (1960-2010), as a function of the return period. We adopt a regional non-stationary flood frequency approach to attribute observed flood changes to potential drivers, used as covariates of the parameters of the regional probability distribution of floods. The elasticities of floods with respect to the drivers and the regional contributions of the drivers to changes in flood quantiles associated with small and large return periods (i.e. 2-year and 100-year floods, respectively) are estimated by Bayesian inference, with prior information on the elasticity parameters obtained from expert knowledge and the literature. The data-based attribution approach is applied to annual maximum flood discharge seires from 2370 hydrometric stations in Europe. Extreme precipitation, antecedent soil moisture and snowmelt are the potential drivers considered. Results show that extreme precipitation mainly contributes to positive flood changes in North-western Europe. Both antecedent soil moisture and extreme precipitation contribute to negative flood changes in Southern Europe, with relative contributions varying with the return period. Antecedent soil moisture contributes the most to changes in small floods (i.e. T=2-10 years), while the two drivers contribute with comparable magnitude to changes in more extreme events. In eastern Europe, snowmelt clearly drives negative changes in both small and large floods.</p>