Search

The former mining of rock and potassium salt deposits in Transcarpathia and Nearcarpathia (western Ukraine) has a potential impact on water resources and the transboundary spread of saline pollution (e.g. Solotvyno rock salt deposit on the banks of the Tisza River on the Ukraine-Romania border; Kalush-Golyn potassium-magnesium salt deposit in the Dniester River basin). The threat of pollution spreading increases during floods, flash floods, and flooding. The aim of the study is to determine the extent of possible flooding based on the analysis of natural and man-made factors and using remote sensing data. The probabilistic, comparative-analytical and statistical methods, mechanical and mathematical bases of engineering geology in a complex with system analysis approaches were used in research. Geological, engineering-geological, hydrogeological and remote sensing data (Sentinel-1A) have been processed using a geoinformation system to the database of indicators of flooding processes. The territory is ranked according to the probability of flooding. The probability of flooding varies from 0.03 to 0.75 within the floodplain of Tisza river, 0.8-1.0 in places with a high groundwater level at settlement. The highlighted areas by GRD processing images (Sentinel-1A mission) according to the data of 2 flash floods indicate the probable places for flooding development in additional abnormal synoptic precipitation. The water mineralisation assessment on the flooding risk zones was based on the data of hydrological stations and wells for the Quaternary aquifer. The mapping shows that the flood zone includes areas of increased mineralisation (up to 13 g/l), but in the conditions of significant water inflow during a flood, the capture of such mineralisation would not lead to chloride concentration increase in the river after the flood. The developed schemes are proposed for use by municipal authorities in risk management programs. [ABSTRACT FROM AUTHOR]

The intensification of extreme events, due to global climatic changes and irrational land use, has materialised in the change of pluvial regime and high precipitation amounts. Thus, the study of flash floods, as a result of the rain-flow process, has an important place in applied hydrologic research. Floods represent a hazard with high frequency and magnitude in Romania, especially on rivers originating in the Carpathian mountain area, with pluvial and nival source. Therefore, the quantification of flood vulnerability and risk is necessary for a better management of priorities in emergency situations. The flood risk zonation is made in applied hydrology through floodable stripes, which are produced using statistical analysis of past data series and their integration in determinist spatial analysis models. The aim of the present study is to identify the flood risk and the vulnerability of infrastructure by determining the floodable stripes of the main river in Niraj basin, where significant damages have been recorded after flash floods. In order to achieve this, the methodology included a statistical analysis of hydrologic probability using recordings from the last 43 years (1970-2013), as well as field measurements (topographic profiles used as computational sections) integrated in GIS databases and complex spatial analysis models. The results of the spatial analysis model are illustrated through the flood risk map, generated as a product of temporal flood probability and vulnerability of the territory. These results can be successfully used in territorial planning projects and in the management of emergency situations, but can also be included in other spatial analysis models of flood risk. [ABSTRACT FROM AUTHOR]

This paperwork makes an assessment of risk failure in defense works against flood located along and perpendicular on rivers, including natural riparian wetlands. Highlighting these areas allow us to make complex studies about the different possibilities of flood mitigation, considering the surfaces and lowering the flood risk. Explanations about the "hazard - risk" scheme are made, with flood analyses in many case studies to propose a computation model for risk and management assessment accordingly with the risk and hazard maps. The paper details the risk and safety in three water resource management systems: the overall security degree for transversal systems is influenced by the number and arrangement of the elements; for safety amplification on longitudinal works, the effect of derivations and accumulations in the upstream over the discharge, and the prediction time are important; for the riparian wetlands the state at a given moment is determinant. [ABSTRACT FROM AUTHOR]