No abstract

Disaster risk management involves reducing disaster damage to homes, critical infrastructure and the interruption of basic services and developing their resilience. This work analyzes the perception of geohydrological risk by the population living or working in the town of Cuyocuyo (southern Peru), which was affected in previous years by events of landslides, debris flow and floods. In order to analyze the effect of the social perception of geohydrological risk on disaster preparedness in areas under threat from landslides and debris flow, a survey was applied to 65 adult heads of household. The method for estimating results was logit regression. The results show the following: First, the preparation through the acquisition of items necessary to avoid the impact of the disaster is related to indicators of perception of disaster risk and the age of the population. Second, the knowledge and prevention of disaster mitigation significantly depends on indicators of dependency of the place and the affection of the place. Third, the participation of households in trainings and drills to prevent disasters organized by the government depends significantly on the indicators of the perception of probability of the disaster, threat of disaster risk and the identity of the place and Fourth, the modification and reinforcement of the buildings of the settlers depends positively on the dependence of the place.

<p>Monitoring trends and continuous changes to complement local studies on discharge and precipitation are becoming increasingly important, assessing systematically its temporal and spatial variation characteristics. It is also necessary to provide detailed study on the driving mechanisms of those variations, which can be a result of anthropogenic activities as it specifically affects particular regions and terrains. These data play very significant roles in measuring and forecasting potential impacts and lead to future improved regional flow regulations for better water resources management. One of the most effective methods for observing the effects of climate change on hydrometeorological variables is the trend analysis, with recently new graphical methods that represents an innovative alternative to the classical ones. In this work, mean monthly, annual mean, minimum and maximum precipitation was examined to analyze spatiotemporal variations, seasonality shifts and trends with records that can extend from 1910 to 2019 in the hydrometeorological network. The flow discharge were also analysed considering catchments with unimpaired streamflow in unregulated rivers. Different homogeneity and shift detection methods were used to check their homogeneity before conducting trend analysis. Innovative Polygon Trend Analysis (IPTA), Innovative trend analysis (ITA) with the Significance Test and Mann-Kendall (MK) non-parametric methods were compared, showing their sensitivity and their ability to explain a monthly trend sequence and periodicity in the studied region in order to explain adequately the temporal internal variability.</p>

<p>The Nanay Bridge, Peru's largest bridge, is located on the Nanay Rive near its mouth to the Amazon River in the city of Iquitos, connecting different communities. The Nanay Bridge is 2,283.50 m long and 14.80 m wide. The construction of this structure was completed in November 2021, ensuring, and improving transportation. This research is aimed to the numerical investigation of the hydrodynamic conditions in an Amazonian River reach (Nanay) and is interaction with the mentioned bridge. To this end, The IRIC Nays CUBE and HEC-RAS models were used to simulate unsteady fully two and three-dimensional flow with non-hydrostatic water pressure and high vertical accelerations and velocities. It allows to represent the flow characteristics on the different piers as well as the water level at a certain lateral distance. Different experiments using mean, minimum and maximum flows for different return periods were conducted. Field ADCP and flow measurement data was used for characterization and validation purposes. Estimations of scour around the piers were carried out to quantify the impact of different flows in these elements. The three-dimensional flow structure plays an important role for determining the appropriate countermeasures for local scouring and protection. Our simulation results show that two and three-dimensional flow patterns match the conceptual model of river flow in this type of water courses. Our findings provide useful insight to verify the impact that the implantation of different infrastructures around the Amazonian water courses could produce. This contribution is pointed to be a support in river engineering in Amazonian rivers and might be more valuable in conjunction with physical hydraulic model investigation.</p>

<p>The Madre de Dios river basin belongs to the Amazon river basin, until the study area has an approximate area of ​​47070 km<sup>2</sup>. In recent years serious problems of lateral undermining are occurring on the right bank of the river, bringing with it problems in nearby towns and the layout of the interoceanic highway that connects to the country of Brazil. The case study is the Meander “La Pastora”, whose right margin is constituted by a compact clay material, which was affected by local undermining phenomena, also the approach of thalweg and sedimentation in the left margin was caused by causes of deforestation of the basin and increased solid contribution. Since 2015, measures have been built that have the function of mitigating erosion on the right bank and recovering the affected area. Using two-dimensional numerical modelling, ADCP/multibeam bathymetric surveys and limnimetric records, the hydrodynamic conditions and sediment transport will be evaluated by the hand of a results from physical modelling and inclusion of structural measures, estimating erosion and sedimentation areas that may have been in the meander. BASEMENT and IRIC NAYS2DH-FASTMECH models were used which simulated the flow conditions in different minimum and maximum hydrological scenarios compared with physical modelling results and field data, considering sediment flux corrections in curved channels with significant secondary flow motions and lateral erosion to precisely capture the complex flow field induced by channel curvature and riverbank gravitational effects.</p>