Torrential Floods Research Articles

AXBOROT URUSHI TUSHUNCHASINING G‘OYAVIY TABIATI VA MAFKURAVIY XUSUSIYATLARI

The article provides a scientific basis for the concept of information warfare, its ideological nature and ideological features. Since globalization processes and information society trends have a negative impact on people's consciousness in every region, an important task is to eliminate it and enhance its positive impact. It is impossible to adapt to this phenomenon without studying it deeply and, if necessary, changing its direction accordingly. Failure to thoroughly study the threats in the modern global world, failure to develop a strategy, tactics and technologies for their elimination are equivalent to surrendering the country's economy, culture and spirituality to a torrential flood from the mountains or a sea typhoon.

Application of Remote Sensing for Identifying Soil Erosion Processes on a Regional Scale: An Innovative Approach to Enhance the Erosion Potential Model

Soil erosion represents a complex ecological issue that is present on a global level, with negative consequences for environmental quality, the conservation and availability of natural resources, population safety, and material security, both in rural and urban areas. To mitigate the harmful effects of soil erosion, a soil erosion map can be created. Broadly applied in the Balkan Peninsula region (Serbia, Bosnia and Herzegovina, Croatia, Slovenia, Montenegro, North Macedonia, Romania, Bulgaria, and Greece), the Erosion Potential Method (EPM) is an empirical erosion model that is widely applied in the process of creating soil erosion maps. In this study, an innovation in the process of the identification and mapping of erosion processes was made, creating a coefficient of the types and extent of erosion and slumps (φ), representing one of the most sensitive parameters in the EPM. The process of creating the coefficient (φ) consisted of applying remote sensing methods and satellite images from a Landsat mission. The research area for which the satellite images were obtained and thematic maps of erosion processes (coefficient φ) were created is the area of the Federation of Bosnia and Herzegovina and the Brčko District (situated in Bosnia and Herzegovina). The Google Earth Engine (GEE) platform was employed to process and retrieve Landsat 7 Enhanced Thematic Mapper plus (ETM+) and Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI/TIRS) satellite imagery over a period of ten years (from 1 January 2010 to 31 December 2020). The mapping and identification of erosion processes were performed based on the Bare Soil Index (BSI) and by applying the equation for fractional bare soil cover. The spatial–temporal distribution of fractional bare soil cover enabled the definition of coefficient (φ) values in the field. An accuracy assessment was conducted based on 190 reference samples from the field using a confusion matrix, overall accuracy (OA), user accuracy (UA), producer accuracy (PA), and the Kappa statistic. Using the confusion matrix, an OA of 85.79% was obtained, while UA ranged from 33% to 100%, and PA ranged from 50% to 100%. Applying the Kappa statistic, an accuracy of 0.82 was obtained, indicating a high level of accuracy. The availability of a time series of multispectral satellite images for each month is a crucial element in monitoring the occurrence of erosion processes of various types (surface, mixed, and deep) in the field. Additionally, it contributes significantly to decision-making, strategies, and plans in the domain of erosion control work, the development of plans for identifying erosion-prone areas, plans for defense against torrential floods, and the creation of soil erosion maps at local, regional, and national levels.

A qualitative analysis of cascading effects of critical infrastructure service failure post torrential floods in formal & informal settlement: the study-case of Medellin city, Colombia

ABSTRACT Critical infrastructure (CI) services are crucial to the functioning of modern communities, and a single CI failure can cause cascading effects through a network of services, impacting an entire city. Challenges such as climate change and rapid urbanisation are increasing the risk of cascading effects of CI failure, particularly impacting the urban poor in peri-urban and informal settlements. This study uses a systems thinking approach to validate the hypothesis if CI services are susceptible to generating severe cascading effects in informal than formal settlements. Qualitative data was collected on cascading effects via interviews and focus group discussion in a formal and an informal settlement in Medellin, Colombia. The responses were analysed and structured using a service chain framework and a Causal Loop Diagram. Our findings show that cascading effects vary between the formal and informal contexts concerning CI service availability and accessibility and may be attributed to differences in demography, geography, socio-economic development, risk regulations, community coping capacities and other factors associated with urban development.

Temporal and Spatial Distribution Characteristics of Torrential Flooding Disasters with Different Intensities in Tarim Basin

As torrential flooding often cause huge economic losses and casualties, analyzing the spatio-temporal variation characteristics of torrential flooding events is of great significance to disaster prevention and reduction. Based on five indicators for torrential floodingin the Tarim Basin in 1990-2019, ratio weighting and non-dimensional linear summation were employed to calculate disastrous loss indicators that represent disaster intensity. Afterwards, percentile method was used to divide disasters into four levels, i.e., general, relatively severe, severe and extremely severe. The results showed that the regions where Level-1 to Level-4 disasters frequently and recurrently occur are concentrated in Kizilsu Kirghiz Autonomous Prefecture, Aksu Prefecture and Kashgar Prefecture and that such disasters often take place from April to July. The interannual variation of the frequency and intensity of Level-1 disasters presented a linear upward trend, and the frequency and disastrous loss indicator increased by 14.6 and 0.8 per 10a, respectively. The interannual variation of the frequency and intensity of Level-2 to Level-4 disasters did not show a linear increase or decrease trend. The threshold for 12-hour precipitation that may cause torrential flooding in the basin from March and October is 10mm. The annual frequency of 12-hour precipitation exceeding the threshold increased year by year, so did the frequency and intensity of Level-1 disasters.

Unveiling Torrential Flood Dynamics: A Comprehensive Study of Spatio-Temporal Patterns in the Šumadija Region, Serbia

This paper presents a comprehensive analysis of flood frequency and a spatio-temporal characterization of historical torrential floods in the Šumadija region using water discharge datasets and documented events. A chronology of 344 recorded torrential flood events, spanning from 1929 to 2020, illustrates the region’s vulnerability, with a death toll exceeding 43. The study defines the intra-annual primary and secondary peaks of torrential flood occurrences and explains their spatial distribution. Furthermore, the identification of suitable probability distribution functions underscores the necessity of tailored approaches for effective flood risk management in this diverse geographical environment. The study employed Flood Frequency Analysis (FFA) and goodness-of-fit tests, including the Kolmogorov–Smirnov (K-S) and Cramér–von Mises (CvM) tests, to assess the frequency and magnitude of flood events and evaluate diverse distribution functions. The main results include the identification of suitable probability distribution functions for each river within the region, emphasizing the need for tailored approaches in flood risk management. Additionally, discharge values for various return periods offer crucial insights for informed decision-making in flood risk management and infrastructure planning.

Flood risk assessment, a case study in an arid environment of Southeast Morocco

Abstract Since the early 1980s, several regions of Morocco have experienced alternating series of wet and dry periods related to climate change, with significant consequences for the country’s economy. This study aims to map flood hazards by using a hydraulic modeling approach, with a specific focus on the Oued (river) Zaouiat Sidi Hamza passing through Zaouiat Sidi Hamza township belonging to the High Ziz watershed (province of Midelt, region of Drâa-Tafilalet, Morocco). Hydraulic modeling and flood simulation were carried out followed by mapping of the flood hazard. The Oued Zaouiat Sidi Hamza River can cause torrential flooding issues, particularly during periods of heavy storms, impacting agricultural land and certain buildings on both river banks. All the cultivated areas developed alongside the river are at risk of flooding. Moreover, undermining and erosion of the river’s banks lead to rising high-water levels and flooding agricultural terraces. The use of geographic information systems and hydraulic modeling tools is essential to gain a deeper understanding of this situation. Also, the mapping of lineaments and fractures in the study area, carried out by satellite image processing, helped to quantify the directional influence of these lineaments on the flow of the hydrographic network, on the orientation of the circulation of surface water, and on the storage of groundwater. According to this study, the most vulnerable areas to flooding and erosion are those that receive the most water in the basin and have steep slopes. Decision-makers can use the results to produce development plans tailored to combat these risks and raise awareness among the population concerned, improving water resource evaluation and forecasting, as well as improving agricultural production.

Assessing flood risks and exploring opportunities for flood-based farming in the dry lowlands of Ethiopia

Food grown in the rainfed system in Ethiopia is frequently insufficient to meet household food needs due to recurrent drought, which causes severe food insecurity. Ethiopia’s drylands have also been hit by an increase in torrential floods. As a result, the ability to adapt to shocks and risks decreases. Despite the opportunity of highland-to-lowland to lowland connectivity, the opportunities for flood-recession farming are poorly understood. This study maps flood recession opportunities incorporating national flood occurrence information, flood images, and SMAP surface soil moisture from Soil Moisture Active Passive (SMAP) images in Omo Gibe basin and Mile sub-basin. The analysis demonstrates that during the past three decades, there have been substantial flood incidents in the country’s eastern, south-eastern, and southern regions. Notably, floods that happened in 1996, 2005, 2006, 2013, and 2018 affected 90, 91, 74, 74, and 69 locations, respectively. In 2020, flooding affected a considerable area (274 locations), which demonstrates the rise in flood hazards. Based on multi-criteria suitability analysis, about 32 million hectares of lowlands are highly suitable (61%) and moderately suitable (39%) for flood-based farming. In the Omo-Gibe and the Mile sub-basin, flood-recession zone mapping using a change detection approach revealed that Omo-Gibe basin has 107,359 ha and 29,550 ha of flood zones suitable for flood recession farming and Mile sub-basin of 8,048 ha and 88 ha, during the major and short rainy seasons, respectively. Our results highlight the extent of flood-prone areas and their suitability for flood farming and provide evidence of alternative strategies for managing flood risks. Consequently, identifying potential flood-prone areas using remote sensing technology aids decision-makers and subject-matter experts in introducing and demonstrating various types of flood-based farming. Further research is recommended to identify and validate appropriate flood farming practices under different biophysical and socio-economic contexts and explore complementary opportunities as well as support informed decision-making on flood risk management and recession flood strategies in the dry lowlands of Ethiopia.

Two-dimensional flooding model using IBER software case Study: Saidia City North east of Morocco

In the last two decades, Morocco has suffered a lot from catastrophic flooding, resulting in enormous damage to materials and loss of human life. The Sadia City (northeast Morocco), in our case of this study, is the most urbanized area with a high concentration of socio-economic activities in the region. Sadia is located downstream of the Moulouya watershed known for its low topography, and high vulnerability to fluvial and torrential flooding. The study aims to simulate the flood hazard index in the city of Saidia and consists of developing a two-dimensional (2D) flooding model using IBER software, and then producing maps of water flow and water velocity based on a 1-meter DTM. Then, we use GIS to map the hazard index of the areas with a high risk of flooding over a return period of 50 years. These hydraulic models were used to elucidate the risk of the Moulouya River overflowing its catchment area and to assist the stakeholders in decision-making about adequate measures to protect human life in Saidia City.

Incorporating cascading effects analysis in the maintenance policy assessment of torrent check dams against torrential floods

In mountainous regions, protection infrastructures designed to mitigate the impacts of torrential floods often consist of a complex system of several structural components (check dams). Over time, the efficacy of this system in protecting downstream assets diminishes as the structural components deteriorate. The extent of deterioration is influenced by the interdependencies between the failure modes of individual components, as well as those between multiple components of the system. Understanding and quantifying the chain of failure events, known as cascading effects, is a critical scientific challenge that remains largely unexplored. In this study, we propose a novel approach that employs physics-based models to examine the deterioration of a series of check dams over time, while considering failure dependencies and bidirectional interactions between consecutive dams. The results obtained from this approach reveals that the absence of a downstream dam accelerates the deterioration rate of upstream dams, while its presence serves to stabilize them. We further incorporate stochastic deterioration and maintenance processes using Stochastic Petri nets to support decision-making regarding maintenance actions for each dam, while also considering economic factors. Strategies involving minor operations achieved cost-effectiveness and prolonged satisfactory performance of the dams, with notable impacts from upstream and downstream dam presence on maintenance costs. We illustrate our approach using a case study of the Faucon torrent in France, where we model the deterioration of three consecutive check dams subjected to torrential floods over a period of 100 years.

Mountain protective forests under threat? an in-depth review of global change impacts on their protective effect against natural hazards

Forests in mountain areas provide an indispensable ecosystem service by protecting people and infrastructure against natural hazards. As forests are increasingly affected by global change, including climate change, more frequent and severe natural disturbances, and shifts in land use, open questions remain regarding the long-term and sustainable provision of this crucial protective service. To improve our understanding of the various effects of global change on protective forests, we summarized the current knowledge based on a systematic review. Focusing on changes in mountain forests’ protective effect against snow avalanches, landslides, rockfall, torrential floods and debris flow, we assessed 72 peer-reviewed, English publications. Overall, climate-induced changes are expected to increase forests’ protective effect at higher elevations but reduce it at lower elevations mainly due to increased drought. Natural disturbances usually decrease the protective effect of forests, and their impact is often further exacerbated by salvage logging. Different forest management strategies are often studied using forest simulation models, and their impacts on protective forests strongly depend on the local context and interactions with climate change. While clearcuts consistently reduce the protective effect, other forest management interventions such as thinning can have either positive or negative effects. Most of the reviewed studies were case studies based on forest simulation or process-based hazard models (but rarely combining the two), while empirical evidence was scarce. Forests’ protective effect is often assessed using (diverse) indicators of forest structure, but evaluations of resulting risks are less common. More consistent modeling approaches linking forest structure to hazard and risk, as well as consistent indicators across different case studies, are needed for a better understanding of changes in protective forests and the service they provide under global change.

The reconstruction of the great 2020 torrential flood in Western Serbia

The reconstruction of the great 2020 torrential flood in Western Serbia

Survey and documentaiton of plants from Southern Coimbatore

Plants in densely urbanized areas also contribute to environmental protection from several hazards like strong winds, soil and slope erosion, torrential floods, landslides. The floristic documentation was carried out in four regions of Southern Coimbatore. Out of 96, there are 77 are cultivated plants as agricultural crops, ornamental or other consumption purposes and remaining 19 are wild plants around the residing area. This present analysis indicated that documented plant species came under 43 taxonomic families. Highest number of species found in the family Cucurbitaceae (7), Apocynaceae (6) followed by Amaranthaceae, Arecaceae, Fabaceae, Poaceae each with 5 species. It is also revealed that the highest number of Herb habits (37.5%) followed by trees (20.83%) than other habits. Among which most of the plants are used for medicine and domestic consumption. Several plants have been cultivated for ornamental purposes as well. In this survey, no rare status plants have been observed in this study area. Hence it is indicating that the area is completely civilized and the land area around the residence has been anthropogenic impacted. The wild species documented in this area are herbaceous weed plants blooming at every rainy season. Hence the cultivation of trees and protection management has to be initiated to increase the green cover of the study area -Southern Coimbatore to regain the misty, moderate climate as it was one of the identity of Coimbatore. It will definitely improve the ecological services like rainfall, pure air and beauty of nature to enjoy.

Research on flood sediments and rainstorm events in Huangtuwa, Northern Shaanxi

The research purpose of this paper is to reveal the relationship between flood deposits, rainfall and flooding in the Loess Plateau over the last 50 years. The research in this paper is of great significance as it reveals the torrential flood events and soil erosion in the central region of the Loess Plateau. Through grading analysis and 137Cs content determination of a closed lake sedimentary profile formed by landslide-blocked rivers in middle part of Loess Plateau, Zizhou County, Shaanxi Province, the age of the sedimentary formation in the section, as well as the rainstorm events and changes of soil erosion since 1954 are studied. The results show that the sediment particle size composition in the study section is fine, mainly comprising of coarse silt, while the content of sand particles (>100 μm) is very low. The changes in137Cs content show that the sedimentary layer at a depth of 280–210 cm in the research profile was formed between 1954 and 1964, while the deep sedimentary layer at 210–70 cm was formed between 1965 and 1986 and the sedimentary layer above 70 cm depth was formed between 1987 and 2011. In total, 20 coarse particle layers (particle size >50 μm) were deposited in the lake between 1954 and 2011. The sedimentation timing of the 20 coarse particle layers was basically consistent with the timing of rainstorm events (daily rainfall ≥60 mm) in the study area, indicating that the coarse particle sediments in the lake represent rainstorm events. Soil erosion was stronger between 1954 and 1985 and was weaker after 1986.

Multi-Hazard Susceptibility Assessment Using the Analytical Hierarchy Process in Coastal Regions of South Aegean Volcanic Arc Islands

Coastal environments are highly recognized for their spectacular morphological features and economic activities, such as agriculture, maritime traffic, fishing, and tourism. In the context of climate change and the evolution of physical processes, the occurrence of intense natural phenomena adjacent to populated coastal areas may result in natural hazards, causing human and/or structural losses. As an outcome, scientific interest in researching and assessing multi-hazard susceptibility techniques has increased rapidly in an effort to better understand spatial patterns that are threatening coastal exposed elements, with or without temporal coincidence. The islands of Milos and Thira (Santorini Island) in Greece are prone to natural hazards due to their unique volcano-tectonic setting, the high number of tourist visits annually, and the unplanned expansion of urban fabric within the boundaries of the low-lying coastal zone. The main goal of this research is to analyze the onshore coastal terrain’s susceptibility to natural hazards, identifying regions that are vulnerable to soil erosion, torrential flooding, landslides and tsunamis. Therefore, the objective of this work is the development of a multi-hazard approach to the South Aegean Volcanic Arc (SAVA) islands, integrating them into a superimposed susceptibility map utilizing Multi-Criteria Decision-Making (MCDM) analysis. The illustrated geospatial workflow introduces a promising multi-hazard tool that can be implemented in low-lying coastal regions globally, regardless of their morphometric and manmade characteristics. Consequently, findings indicated that more than 30% of built-up areas, 20% of the transportation network, and 50% of seaports are within the high and very high susceptible zones, in terms of the Extended Low Elevation Coastal Zone (ELECZ). Coastal managers and decision-makers must develop a strategic plan in order to minimize potential economic and natural losses, private property damage, and tourism infrastructure degradation from potential inundation and erosion occurrences, which are likely to increase in the foreseeable future.

Application of the Flash Flood Potential Index in torrential floods risk assessment (FFPI): A case study of Svilajnac municipality

Application of the Flash Flood Potential Index in torrential floods risk assessment (FFPI): A case study of Svilajnac municipality

Fire microfacies and pyroresidues tracing atmospheric electrification impacts on the Moche Valley and on the Mochica (North Peru)

The effects of environmental events on living conditions during occupation periods are studied by comparing alluvial soils and occupation floors that formed during the late Holocene in the Moche valley (North Peruvian coast). The microcontextual study comprises (1) microsurface identification in the field; (2) micromorphological analysis of thin sections; (3) multi-scale characterization of soil components based on digital stereo microscope and scanning electron microscope analysis. The alluvial sequence consists of a 6 m thick alternation of organic silty-clay, fine sandy strata with well-preserved ashy charcoal strata and massive grey sandy beds. This cyclical pattern reflects alternation of stable episodes with a dense reed-bed vegetation, regularly affected by wildfires and drought marked by sand invasions from coastal dunes during El Niño events. The 14C dates show that these contrasting conditions lasted for one millennium up to establishment of the Mochica empire at the Huaca at 300 years cal. BC. Vesicular slags produced by flash-melting of the soil components, biosourced quartz and nanostructured polymers formed from flash-ionization of the reed vegetation, all with FeCrNi metals coatings, were retrieved in the fired surfaces. They trace impact at the soil surface of electrically charged particles, lightning-flashes, nanoaerosol production by enhanced atmospheric electrification, i.e., flash-heating, shock vaporization, plasma-polymerization of the vegetation and the host matrix. The study shows the occurrence in the basal Uhle platform occupation deposits at the foot of the Huaca de la Luna of similar cemented ashy microfacies associated with a funerary deposit with food offerings in ritual vessels and an intriguing scoriaceous slag. The evidence for ritual disposal of imperishable offerings to deaths is interpreted as the memorial record of the Mochica knowledge of long-lived materials produced by lightning-triggered plasma processes. This integrated study of the environmental and cultural contexts refutes previous assumptions of long-term engineering of the arable alluvial plain to counteract sand invasion and torrential floods. In contrast, the establishment of the Moche pyramids is shown to have occurred during a period of floodplain stability marked by high-energy natural events and lightning processes that offered access to durable soil resources of important social values.

The Impact of Depopulation on Reduction of the Peaks of Torrential Floods in Selected Watersheds of the Southeastern Serbia

The processes of emigration, depopulation and deagrarization in hilly-mountainous border areas in Serbia have intensified in last several decades. These processes have resulted in land use changes which means that anthropogenic impact on environment has diminished so the agriculture areas have decreased and have made room to the other land use types. These changes should entail lower soil erosion, slower generation of surface runoff during rainfall episode as well as reduction of the peak discharges and destructiveness of a torrential flood event. In this paper, we quantified the influence of land use changes on surface runoff indicators for 15 watersheds in the Southeastern Serbia. The greatest reduction of the curve number (CNR) happened in the Toplodolska watershed (2.34), then the Korbevačka (1.98) and the Dojkinačka (1.60) watersheds. The decrease of maximal discharge of 100-year return period is presented on example of a small watershed of the Ravna reka and it equals to 11%. It is expected that noticed land use changes will have the same trend, meaning that CN numbers will continue decreasing. Alongside these spontaneous positive anthropogenic impact on lowering the peaks of torrential floods, there should be a set of other preventive measures implemented.

THE IMPACT OF DEPOPULATION ON REDUCTION OF THE PEAKS OF TORRENTIAL FLOODS IN SELECTED WATERSHEDS OF THE SOUTHEASTERN SERBIA

The processes of emigration, depopulation and deagrarization in hilly-mountainous border areas in Serbia have intensified in last several decades. These processes have resulted in land use changes which means that anthropogenic impact on environment has diminished so the agriculture areas have decreased and have made room to the other land use types. These changes should entail lower soil erosion, slower generation of surface runoff during rainfall episode as well as reduction of the peak discharges and destructiveness of a torrential flood event. In this paper, we quantified the influence of land use changes on surface runoff indicators for several watersheds in the Southeastern Serbia. The greatest reduction of the curve number (CNR) happened in the Toplodolska watershed (2.34), then the Korbevačka (1.98) and the Dojkinačka (1.60) watersheds. The decrease of maximal discharge of 100-year return period is presented on example of a small watershed of the Ravna reka and it equals to 11%. Alongside these spontaneous positive anthropogenic impact on lowering the peaks of torrential floods, there should be a set of other preventive measures implemented.

Responses and adjustments of the coastal systems of Dominica (Lesser Antilles) when faced with an extreme event: Hurricane Maria (September 2017)

Dominica was hit hard by Hurricane Maria, a category 5 storm when it passed over the island on September 18, 2017. This study aims to characterise the dynamics associated with this event and their consequences in the medium term on the morphology and the coastal structures of this Caribbean island nation. Based on a multi-site approach (9 sites), this study uses varied data (satellite and aerial images, databases, reports, and numerical modelling) and the validation thereof via qualitative observations and topo-morphological surveys carried out in the field 18 months after the hurricane. The high-resolution modelling of the hydrometeorological conditions during the hurricane, the monitoring of the changes in the shoreline, and the field observations brought to light the prevalence of fluvio-sedimentary hazards (torrential flooding and ground movements) over marine hazards (marine flooding and storm swell) in the modification of the coastal landscapes. Phenomena of massive sediment discharge caused considerable damage to the buildings located in low-lying areas and flood plains and to road infrastructure, which hindered access to certain sectors of the island in the post-storm phase for a significant period of time. The more-limited damage of marine origin was exacerbated by the artificialisation of the coast and the establishment of a permanent shoreline. We demonstrate that the impact model for Hurricane Maria for the coastal areas of Dominica is the result of a combination of natural factors with a particular exposure and vulnerability of coastal populations and structures to hydrometeorological risks.

A METHODOLOGY FOR MAPPING AREAS UNDER TORRENTIAL FLOOD RISK: CASE STUDY - THE REBROVAČKI BROOK BASIN / BANJA LUKA MUNICIPALITY (B&H)

Torrential floods are one of the most common and destructive natural hazards that cause great material damage and numerous environmental problems. This article is focused on presentation of a new methodological approach to mapping torrential flood risk that could potentially be applied to other torrential rivers in Bosnia and Herzegovina. A hybrid digital terrain model was developed using geodetic surveys of cross-sections of river channels and river valleys and the existing digital terrain model. This was a basis for hydraulic modelling in HEC-RAS software. Hydrological modelling determined flood flows of 100 and 500-year return periods, ranging from 23m3/s to 88m3/s. Hydraulic modelling determined depths, velocities and extent of flooding for different return periods, values of erosion and sediment accumulation, and shear stresses along the Rebrovački Brook. Maximum velocities of 100-year flood flows range up to 11.07m/s and up to 12.41m/s for 500-year flood flow. Depth of 100-year flood flows range up to 3.96m and 4.67m for 500-year flood flow. For 100-year return period the flood extent is 34.53ha, while for 500-year return period it is 46.11ha. Shear stresses of the Rebrovački Brook for 100-year flood flows range to a maximum of 3,482N/m2, while they are maximum 5,348N/m2 for 500-year return period. Maximum values of erosion and sediment accumulation of 100-year flood flow for the Rebrovački Brook are 0.59m for erosion and 1.50m for sediment accumulation, while for 500-year return period they are 3.50m for erosion and 1.66m for sediment accumulation. During the preparation of the flood hazard maps, a new formula was proposed which determined the flood hazard rating of the Rebrovački Brook for 100 and 500-year floods. The resulting maximum hazard ratings of 68.90 for 100-year flood and 69.28 for 500-year flood are several times higher than the values obtained on alluvial rivers. The flood risk factors for the categories of population and economy in the Rebrovački Brook basin were determined on the basis of the obtained flood hazard rating and corrected weighted factors for the calculation of flood risk. Risk maps for floods of different return periods of the Rebrovački Brook showed that most of the floodplain is currently in a zone of negligible or low risk. However, given the current trend of city expansion and relocation of economic activities from the centre to the suburbs, this is slowly changing to high and extreme risk. The proposed methodology for developing torrential flood hazard and risk map, tested in several other basins in Bosnia and Herzegovina, gave acceptable outcomes according to the validation results, and also provides a good basis for numerous studies and projects in flood risk management, environmental protection, spatial planning, and other areas of human action.