scholarly journals Estimation of flash flood hazard in the Pidima-Arfara area (Messinia, SW Greece), based on the study of instantaneous unitary hydrographs, longitudinal profilesand stream power

2007 ◽  
Vol 40 (4) ◽  
pp. 1621
Author(s):  
E. Sambaziotis ◽  
I. Fountoulis
Keyword(s):  
Flash Flood ◽  
Flood Hazard ◽  
Flash Floods ◽  
Topographic Map ◽  
Stream Power ◽  
Longitudinal Gradient ◽  
Hydrological Simulation ◽  
Small Catchment ◽  
Map Scale ◽  
Good Agreement

In this paper it is an effort to combine different methodologies in order to locate the sensitive sites in flash flood phenomena in a relatively small catchment located north of Kalamata (Messinia SW Péloponnèse, Greece). Based on digitised topographic map (scale 1/5.000) the longitudinal, gradient and stream power profiles of the watercourses were constructed and the results (possibly sensitive to flash floods sites) were compared to ones that came from applying hydrological simulation, hydrographs as well as Instantaneous Unitary Hydrographs. The comparison showed that the results were in good agreement.

The Utilization of GIS in Revealing the Reasons behind Flooding Ras Gharib City, Egypt

2017 ◽  
Vol 31 ◽  
pp. 135-142 ◽  
Author(s):  
Hesham Ezz
Keyword(s):  
Natural Disasters ◽  
Spatial Resolution ◽  
Flash Flood ◽  
Flood Hazard ◽  
Shuttle Radar Topography Mission ◽  
Flash Floods ◽  
Topographic Map ◽  
Gis Environment ◽  
The City

Flash floods in Egypt are considered the worst weather-related natural disasters. They are dangerous as they suddenly and unpredictably occur. Ras Gharib City is one of the recent cities that was subjected to a destructive flash flood in October 2016. The city was founded 85 years ago and it has no flood hazard history. This paper presents the utilization of GIS environment in estimating the drainage streams discharging towards the city using Shuttle Radar Topography Mission (SRTM) 30m spatial resolution. Two scenarios are conducted in this study to show why Ras Gharib was subjected to a flash flood. In the first scenario, a drainage map is conducted using the normal elevations extracted from the topographic map. In the second scenario, a drainage map is conducted using the same extracted elevations after elevating Minya - Ras Gharib Highway with 1.5m. The study shows that elevating the highway is the main reason of subjecting the city to this flood causing 11 dead people and 36 injured.

scholarly journals Designating Appropriate Areas for Determining Potential Rainwater Harvesting in Arid Region Using a GIS-based Multi-criteria Decision Analysis ‏

2021 ◽  
Author(s):  
Mohamed Abd-el-Kader ◽  
Ahmed Elfeky ◽  
Mohamed Saber ◽  
Maged AlHarbi ◽  
abed Alataway
Keyword(s):  
Water Management ◽  
Saudi Arabia ◽  
Decision Analysis ◽  
Rainwater Harvesting ◽  
Flash Flood ◽  
Flood Hazard ◽  
Flash Floods ◽  
Flood Mitigation ◽  
Water Harvesting ◽  
Multi Criteria Decision Analysis

Abstract Flash floods are highly devastating, however there is no effective management for their water in Saudi Arabia, therefore, it is crucial to adopt Rainfall Water Harvesting (RWH) techniques to mitigate the flash floods and manage the available water resources from the infrequent and rare rainfall storms. The goal of this study is to create a potential flood hazard map and a map of suitable locations for RWH in Wadi Nisah, Saudi Arabia for future water management and flood prevention plans and to identify potential areas for rainwater harvesting and dam construction for both a flood mitigation and water harvesting. This research was carried out using a spatiotemporal distributed model based on multi-criteria decision analysis by combining Geographic Information System (GIS), Remote Sensing (RS), and Multi-Criteria Decision-Making tools (MCDM). The flood hazard mapping criteria were elevation, drainage density, slope, direct runoff depth at 50 years return period, Topographic witness index, and Curve Number, according to the Multi-criteria decision analysis, while the criteria for RWH were Slope, Land cover, Stream order, Lineaments density, and Average of annual max-24hr Rainfall. The weight of each criteria was estimated based on Analytical Hierarchy Process (AHP). In multi-criteria decision analysis, 21.55 % of the total area for Wadi Nisah was classified as extremely dangerous and dangerous; 65.29 % of the total area was classified as moderate; and 13.15 % of the total area was classified as safe and very safe in flash flood hazard classes. Only 15% of Wadi Nisah has a very high potentiality for RWH and 27.7%, 57.31% of the basin has a moderate and a low or extremely low potentiality of RWH, respectively. According to the developed RWH potentiality map, two possible dam sites were proposed. The maximum height of the proposed dams, which corresponded to the cross section of dam locations, ranged from 6.2 to 9 meters; the maximum width of dams ranged from 573.48 to 725 meters; the maximum storage capacity of reservoirs, which corresponded to the distribution of topographic conditions in the surrounding area, ranged from 3976104.499 m3 to 4328509.123 m3; and the maximum surface area of reservoirs ranged from 1268372.625 m2 to 1505825.676.14 m2. These results are highly important for the decision makers for not only flash flood mitigation but also water management in the study area.

Radar-based rainfall nowcasting for flash flood hazard assessment: recent results at regional and Continental scales

2020 ◽  
Author(s):  
Marc Berenguer ◽  
Shinju Park ◽  
Daniel Sempere-Torres
Keyword(s):  
Real Time ◽  
Hazard Assessment ◽  
Flash Flood ◽  
Flood Hazard ◽  
Spatial Scales ◽  
Flash Floods ◽  
Radar Rainfall ◽  
European Projects ◽  
Rainfall Estimates ◽  
Ne Spain

<p>Radar rainfall estimates and nowcasts have been used in Catalonia (NE Spain) for real-time flash flood hazard nowcasting based on the basin-aggregated rainfall for several years. This approach has been further developed within the European Projects ERICHA (www.ericha.eu) and ANYWHERE (www.anywhere-h2020.eu), where it has been demonstrated to monitor flash floods in real time in several locations and at different spatial scales (from regional to Continental coverage).</p><p>The work summarizes the main results of the recent projects, analysing the performance of the flash flood nowcasting system. The results obtained on recent events  show the main advantages and some of the limitations of the system.</p>

scholarly journals Results of the post flash-flood disaster investigations in the Transylvanian Depression (Romania) during the last decade (2001–2010)

2013 ◽  
Vol 1 (6) ◽  
pp. 6199-6225
Author(s):  
V. Arghiuş ◽  
A. Ozunu ◽  
I. Samara ◽  
G. Roşian
Keyword(s):  
Flash Flood ◽  
Flash Floods ◽  
Flood Risk Management ◽  
Maximum Intensity ◽  
Stream Power ◽  
Negative Effects ◽  
Hydrological Data ◽  
Low Intensity ◽  
Management Measures ◽  
Peak Discharges

Abstract. Flash flood disasters are very rare in the Transylvanian Depression. In the last decades just three events were signalled in the study area, all of them during the last 10 yr. The flash floods occurring in the study area during the last decade had a significant impact on several localities situated at the Transylvanian Depression border. Based on the post flash flood investigation, the present study intends to find out the main characteristics of the flash-floods and the causes that have led to disasters in a region rarely affected by such kind of events. Analyzing the hydrological data, has been seen that the maximum intensity of the flash floods was observed in the upper and middle basins. By comparing the unit peak discharges from the studied region with other specific peak discharges related to the significant flash floods from Romania, it was noticed that the events from the Transylvanian Depression have moderate to low intensity. On the other hand, the results showed that beside high stream power and unexpected character common to flash floods, the inappropriate flood risk management measures increased the dimension of negative effects, leading to tens of life losses and economical damages of tens million dollars.

scholarly journals APPLICATION GIS AND REMOTE SENSINGTO ESTABLISH FLASH FLOOD HAZARD MAP IN TUYEN QUANG PROVINCE

2021 ◽  
Vol 7 (21) ◽  
pp. 142-149
Author(s):  
Văn Trần Đức
Keyword(s):  
High Risk ◽  
Flash Flood ◽  
Flood Hazard ◽  
High Reliability ◽  
Flash Floods ◽  
Hazard Map ◽  
Gis And Remote Sensing ◽  
Rivers And Streams ◽  
Flood Hazard Map ◽  
Hazard Level

Tuyen Quang is one of the provinces at high risk of flash floods in the Northern Midlands and Mountains of Vietnam. In the rainy season, like other localities in the region, Tuyen Quang has a long, concentrated rainfall combined with steep hills and mountains, large divisions, many rivers, and streams; In addition, the thinning of the vegetation cover due to excessive exploitation of the forest by the local people causes flash floods to appear more and more. Applying GIS and remote sensing to establish a map of flash flood risk is a quantitative approach and high reliability. This article has established a flash flood hazard map at a scale of 1/100,000 in Tuyen Quang province. In the map database, districts with a high risk of flash flood were identified, including Na Hang, Chiem Hoa, Ham Yen, and Lam Binh, the average flash flood hazard level included districts: Yen Son, Son Duong; Tuyen Quang city has a low risk of flash floods.

scholarly journals Flood Hazard Mapping Using the Flood and Flash-Flood Potential Index in the Buzău River Catchment, Romania

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2116 ◽  
Author(s):  
Mihnea Cristian Popa ◽  
Daniel Peptenatu ◽  
Cristian Constantin Drăghici ◽  
Daniel Constantin Diaconu
Keyword(s):  
Risk Management ◽  
Flash Flood ◽  
Flood Hazard ◽  
Flash Floods ◽  
Hazard Mapping ◽  
Flood Vulnerability ◽  
River Catchment ◽  
Potential Index ◽  
Vulnerability Maps ◽  
Two Indices

The importance of identifying the areas vulnerable for both floods and flash-floods is an important component of risk management. The assessment of vulnerable areas is a major challenge in the scientific world. The aim of this study is to provide a methodology-oriented study of how to identify the areas vulnerable to floods and flash-floods in the Buzău river catchment by computing two indices: the Flash-Flood Potential Index (FFPI) for the mountainous and the Sub-Carpathian areas, and the Flood Potential Index (FPI) for the low-altitude areas, using the frequency ratio (FR), a bivariate statistical model, the Multilayer Perceptron Neural Networks (MLP), and the ensemble model MLP–FR. A database containing historical flood locations (168 flood locations) and the areas with torrentiality (172 locations with torrentiality) was created and used to train and test the models. The resulting models were computed using GIS techniques, thus resulting the flood and flash-flood vulnerability maps. The results show that the MLP–FR hybrid model had the most performance. The use of the two indices represents a preliminary step in creating flood vulnerability maps, which could represent an important tool for local authorities and a support for flood risk management policies.

scholarly journals The Flash Floods Risk in the Local Spatial Planning (Case Study: Lublin Upland, E Poland)

Resources ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 14
Author(s):  
Bogusława Baran-Zgłobicka ◽  
Dominika Godziszewska ◽  
Wojciech Zgłobicki
Keyword(s):  
Flood Risk ◽  
Local Governments ◽  
Spatial Planning ◽  
Flash Flood ◽  
Flood Hazard ◽  
Flash Floods ◽  
Planning System ◽  
Study Objective ◽  
Change Models ◽  
Risk Maps

Flash floods pose a significant threat to humans but the state of our knowledge on the occurrence and related risk of such phenomena is insufficient. At the same time, many climate change models predict that extreme rainfall events will occur more and more frequently. Identifying areas susceptible to flash floods is more complicated that in the case of floods occurring in the valley bottoms of large rivers. Flood risk maps in Poland have not been developed for small catchments. The study objective was to assess whether the threat related to flash floods is taken into account in the spatial planning system of municipalities. Studies were conducted in the Lublin Upland, E Poland (an area of about 7200 km2). A preliminary assessment of susceptibility of 369 catchments to flash floods was carried out in a GIS environment using multi criteria analysis. The susceptible catchments cover about 30% of the area. Existing planning documents, flood hazard and flood risk maps were analyzed for municipalities located in the catchments with highest susceptibility to this phenomenon. Our results show that flash flood risk is usually not recognized at the level of local governments even when it is significant. Local planning documents do not take into account the existence of this threat.

scholarly journals Estimation of extreme flash flood evolution in Barcelona County from 1351 to 2005

2006 ◽  
Vol 6 (4) ◽  
pp. 505-518 ◽  
Author(s):  
A. Barrera ◽  
M. C. Llasat ◽  
M. Barriendos
Keyword(s):  
Roman Empire ◽  
Flash Flood ◽  
Flood Hazard ◽  
Climatic Variability ◽  
Daily Rainfall ◽  
Weather Conditions ◽  
Flash Floods ◽  
Economic Losses ◽  
Data Series ◽  
Perception Threshold

Abstract. Every year, flash floods cause economic losses and major problems for undertaking daily activity in the Catalonia region (NE Spain). Sometimes catastrophic damage and casualties occur. When a long term analysis of floods is undertaken, a question arises regarding the changing role of the vulnerability and the hazard in risk evolution. This paper sets out to give some information to deal with this question, on the basis of analysis of all the floods that have occurred in Barcelona county (Catalonia) since the 14th century, as well as the flooded area, urban evolution, impacts and the weather conditions for any of most severe events. With this objective, the identification and classification of historical floods, and characterisation of flash-floods among these, have been undertaken. Besides this, the main meteorological factors associated with recent flash floods in this city and neighbouring regions are well-known. On the other hand, the identification of rainfall trends that could explain the historical evolution of flood hazard occurrence in this city has been analysed. Finally, identification of the influence of urban development on the vulnerability to floods has been carried out. Barcelona city has been selected thanks to its long continuous data series (daily rainfall data series, since 1854; one of the longest rainfall rate series of Europe, since 1921) and for the accurate historical archive information that is available (since the Roman Empire for the urban evolution). The evolution of flood occurrence shows the existence of oscillations in the earlier and later modern-age periods that can be attributed to climatic variability, evolution of the perception threshold and changes in vulnerability. A great increase of vulnerability can be assumed for the period 1850–1900. The analysis of the time evolution for the Barcelona rainfall series (1854–2000) shows that no trend exists, although, due to changes in urban planning, flash-floods impact has altered over this time. The number of catastrophic flash floods has diminished, although the extraordinary ones have increased.

scholarly journals Flash floods: formation, study and distribution

2020 ◽  
Vol 163 ◽  
pp. 02005
Author(s):  
Liudmila Kuksina ◽  
Valentin Golosov
Keyword(s):  
Short Duration ◽  
Debris Flows ◽  
Flash Flood ◽  
Flash Floods ◽  
Mountain Areas ◽  
Antecedent Soil Moisture ◽  
Small Catchment ◽  
Natural Factors ◽  
Spatio Temporal ◽  
Equatorial Climate

Flash floods are one of the most widespread and dangerous phenomenon on our planet. They are characterized by fast speed of development and short duration. However their study just begins because there is no one opinion what flash flood is, and there is no special term in many countries. The key reasons of their formation are intensive rainfall of short duration, location of river basin in mountain areas, and small catchment area, providing fast concentration of the runoff in river channel. Another significant factor is antecedent soil moisture. Flash floods are mostly spread in zones of subtropic, tropic and equatorial climate in the northern hemisphere. The study of flash floods is implemented in various fields of science due to hydrometeorological and lythogeomorphological causes of their formation. The important task is the differentiation of flash floods and debris flows. It can be based on the relations between sediment yield and sediments grain size and runoff characteristics with a glance of sediments concentration. The scheme of natural factors of flash floods formation is suggested with their differentiation from debris flows and floods of other types. The main issues of flash floods research and forecast are connected with small spatio-temporal scale of phenomenon and remoteness of river basins.

scholarly journals Flash Flood Early Warning Coupled with Hydrological Simulation and the Rising Rate of the Flood Stage in a Mountainous Small Watershed in Sichuan Province, China

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 255
Author(s):  
Huawei Tu ◽  
Xiekang Wang ◽  
Wanshun Zhang ◽  
Hong Peng ◽  
Qian Ke ◽  
...  
Keyword(s):  
Early Warning ◽  
Flash Flood ◽  
Warning Signal ◽  
Flash Floods ◽  
Sichuan Province ◽  
Mountainous Areas ◽  
Small Watershed ◽  
Hydrological Simulation ◽  
Invention Patent ◽  
Distributed Hydrological Models

Flash floods in mountainous areas have become more severe and frequent as a result of climate change and are a threat to public safety and social development. This study explores the application of distributed hydrological models in flash floods risk management in a small watershed in Sichuan Province, China, and aims to increase early warning lead time in mountainous areas. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) model was used to simulate the flash flood process and analyze the variation in flood hydrographs. First, the HEC-HMS model was established based on geospatial data and the river network shape, and eight heavy rainfall events from 2010 to 2015 were used for model calibration and validation, showing that the HEC-HMS model was effective for the simulation of mountain floods in the study area. Second, with the assumption that rainfall and flood events have the same frequency, the flood hydrographs with different frequencies (p = 1%, 2%, 5%, and 10%) were calculated by the HEC-HMS model. The rising limbs of the flood hydrographs were significantly different and can be divided into three parts (0–5 h, 6–10 h, and 11–15 h). The rising rate of the flood stage for each part of the flood hydrograph increases in multiples. According to the analysis of the flood hydrographs, two critical early warning indicators with an invention patent were determined in the study: the flood stage for immediate evacuation and the rising rate. The application of the indicators in the study shows that it is feasible to advance the time of issuing an early warning signal, and it is expected that the indicators can offer a reference for flash flood early warning in the study area and other small watersheds in mountainous areas.

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