Assessment of flood-risk areas using random forest techniques: Busan Metropolitan City

2022 ◽  
Author(s):  
Jihye Ha ◽  
Jung Eun Kang
Keyword(s):  
Random Forest ◽  
Flood Risk ◽  
Metropolitan City ◽  
Risk Areas

Study of Digital Surface Data for Soils and Flood Risk Areas Mapping in Sudano-Sahelian Zone (Mayo-Danay Division, Far North Cameroon)

2021 ◽  
Vol 10 (1) ◽  
pp. 3473-3491
Author(s):  
TIKI Denis ◽  
◽  
BITOM Mamdem Lionelle ◽  
IBRAHIM Achille ◽  
SOUNYA Jean Boris ◽  
...  
Keyword(s):  
Spatial Data ◽  
Flood Risk ◽  
Multicriteria Analysis ◽  
Urban Environments ◽  
Careful Study ◽  
Risk Areas ◽  
Vertic Soils ◽  
Flooding Risk ◽  
Hazard Level ◽  
Excellent Tool

In general, living close to a river is advantage, but there is always of flooding risk, that recurrence in recent decades provokes serious material damage and loss of life. Thus, in order to protect environmental health, economic viability and human activity zones of Mayo-Danay, a careful study of components of natural environment, mainly soil, has proved essential. Clearly, use of GIS in management of natural disasters is most relevant method, designed on integration, Multicriteria Analysis (MCA) and spatial data. Thus, Digital Elevation Model is obtained by manual digitization of contour lines, in order to define the large pedological sets on which wells have been opened, profiles described, soil samples taken and analyzed in laboratory. Main results reveal that soils are sandy to clayey, with neutral and basic pH (7 to 8), high CEC and low organic matter. While, quartz is predominant, associated with smectites, illites, feldspars and iron oxyhydroxides. Updated soil map shows five soil units (1) vertisols with hydromorphic characters (26%), (2) tropical ferruginous soils (32%), (3) less evolved hydromorphic soils (15%), (4) halomorphic vertic soils (9%), and (5) hydromorphic vertic soils (18%). It is an excellent tool for work and research, that responds to agronomic and development problems. It is therefore an excellent tool for work and research, which responds to agronomic and development problems. The multi-criteria spatial analysis establishes hazard and vulnerability, crossing of which gives of flood risk areas map, according to hazard level, very high (12%), high (16%), moderate (14%), low (30%) and very low (28%) risks. For this purpose, it emerges that rainfall is relatively low (700 mm/year), but falls very abruptly during short periods, at high intensity with flows exceeding the infiltration capacities. Morphology of low-slope "yayrés" (280 m) (2‰) is bordered by high landscape (500 to 1400 m) that prevent flow of many rivers that converge into plain. Sandy soils dominated by quartz favor fast rising in water table, while very clayey soils governed by 2/1 clayey (smectites) whose behavior induce waterproofing and intense surface runoff that generate flooding. Evidently, land use change leads to transformation of natural spaces into agricultural and urban environments, which makes soils more compact and impermeable, favorable to flooding. Keywords Soil; Flood risks; Mapping; Mayo-Danay Division; Spatial data DOI: https://doi.org/10.23953/cloud.ijarsg.501

scholarly journals Vulnerability Assessment of Urban Floods in Lahore, Pakistan using GIS based integrated Analytical Hierarchy Approach

2021 ◽  
Vol 58 (1) ◽  
pp. 85-96
Author(s):  
Sahar Zia ◽  
Safdar A. Shirazi ◽  
Muhammad Nasar-u-Minallah
Keyword(s):  
Land Use ◽  
Flood Risk ◽  
Urban Areas ◽  
Physical Factors ◽  
Urban Flooding ◽  
Residential Areas ◽  
Urban Flood ◽  
Risk Areas ◽  
Practical Tool ◽  
Flood Risk Mapping

Urban flooding is getting attention due to its adverse impact on urban lives in mega cities of the developing world particularly Pakistan. This study aims at finding a suitable methodology for mapping urban flooded areas to estimate urban flooding vulnerability risks in the cities of developing countries particularly Lahore, Pakistan. To detect the urban flooded vulnerability and risk areas due to natural disaster, GIS-based integrated Analytical Hierarchy Process (AHP) is applied for the case of Lahore, which is the second most populous city and capital of the Punjab, Pakistan. For the present research, the flood risk mapping is prepared by considering these significant physical factors like elevation, slope, and distribution of rainfall, land use, density of the drainage network, and soil type. Results show that the land use factor is the most significant to detect vulnerable areas near roads and commercial areas. For instance, this method of detection is 88%, 80% and 70% accurate for roads, commercial and residential areas. The methodology implemented in the present research can provide a practical tool and techniques to relevant policy and decision-makers authorities to prioritize and actions to mitigate flood risk and vulnerabilities and identify certain vulnerable urban areas, while formulating a methodology for future urban flood risk and vulnerability mitigation through an objectively simple and organizationally secure approach. 

scholarly journals Flood risk assessment in selected communes of the Łódź region

2017 ◽  
pp. 21-41
Author(s):  
Marta Borowska-Stefańska
Keyword(s):  
Flood Risk ◽  
Land Development ◽  
Risk Level ◽  
Individual Risk ◽  
Negative Consequences ◽  
Risk Levels ◽  
Risk Areas ◽  
High Flood ◽  
Very High ◽  
Risk Categories

The aim of the article is to assess the present level of land development of flood risk areas in selected communes of the Łódź province in the context of potential negative consequences for people, the natural environment, cultural heritage and economic operations. The research includes urban as well as urban and rural communes (9 communes in total) of the Łódź province which display high and very high flood risk levels according to the methodology used in Flood protection operating plan for the Łódź province from 2013 ( Plan operacyjny… 2013). Uniejów and Warta have the highest synthetic flood risk levels due to the surface occupied by buildings and areas assigned to individual risk categories. In turn, Łowicz and Tomaszów Mazowiecki (town) display the highest general flood risk level due to diversification of buildings and areas of individual risk categories.

scholarly journals Assessment of Flood Risk Map under Climate Change RCP8.5 Scenarios in Taiwan

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 207
Author(s):  
Yun-Ju Chen ◽  
Hsuan-Ju Lin ◽  
Jun-Jih Liou ◽  
Chao-Tzuen Cheng ◽  
Yung-Ming Chen
Keyword(s):  
Climate Change ◽  
High Risk ◽  
Flood Risk ◽  
Spatial Scales ◽  
Disaster Risk ◽  
Decision Makers ◽  
Risk Map ◽  
Climate Data ◽  
Risk Areas ◽  
Flood Risk Map

Climate change has exerted a significant global impact in recent years, and extreme weather-related hazards and incidents have become the new normal. For Taiwan in particular, the corresponding increase in disaster risk threatens not only the environment but also the lives, safety, and property of people. This highlights the need to develop a methodology for mapping disaster risk under climate change and delineating those regions that are potentially high-risk areas requiring adaptation to a changing climate in the future. This study provides a framework of flood risk map assessment under the RCP8.5 scenario by using different spatial scales to integrate the projection climate data of high resolution, inundation potential maps, and indicator-based approach at the end of the 21st century in Taiwan. The reference period was 1979–2003, and the future projection period was 2075–2099. High-resolution climate data developed by dynamic downscaling of the MRI-JMA-AGCM model was used to assess extreme rainfall events. The flood risk maps were constructed using two different spatial scales: the township level and the 5 km × 5 km grid. As to hazard-vulnerability(H-V) maps, users can overlay maps of their choice—such as those for land use distribution, district planning, agricultural crop distribution, or industrial distribution. Mapping flood risk under climate change can support better informed decision-making and policy-making processes in planning and preparing to intervene and control flood risks. The elderly population distribution is applied as an exposure indicator in order to guide advance preparation of evacuation plans for high-risk areas. This study found that higher risk areas are distributed mainly in northern and southern parts of Taiwan and the hazard indicators significantly increase in the northern, north-eastern, and southern regions under the RCP8.5 scenario. Moreover, the near-riparian and coastal townships of central and southern Taiwan have higher vulnerability levels. Approximately 14% of townships have a higher risk level of flooding disaster and another 3% of townships will become higher risk. For higher-risk townships, adaptation measures or strategies are suggested to prioritize improving flood preparation and protecting people and property. Such a flood risk map can be a communication tool to effectively inform decision- makers, citizens, and stakeholders about the variability of flood risk under climate change. Such maps enable decision-makers and national spatial planners to compare the relative flood risk of individual townships countrywide in order to determine and prioritize risk adaptation areas for planning spatial development policies.

scholarly journals FLOOD RISK AREAS SIMULATION USING SWAT AND GUMBEL DISTRIBUTION METHOD IN YANG CATCHMENT, NORTHEAST THAILAND

2020 ◽  
Vol 15 (2) ◽  
pp. 29-39
Author(s):  
Haris PRASANCHUM ◽  
Panuthat SIRISOOK ◽  
Worapong LOHPAISANKRIT
Keyword(s):  
Flood Risk ◽  
Gumbel Distribution ◽  
Northeast Thailand ◽  
Distribution Method ◽  
Risk Areas

scholarly journals A flood risk oriented dynamic protection motivation framework to explain risk reduction behaviours

2019 ◽  
Author(s):  
Philippe Weyrich ◽  
Elena Mondino ◽  
Marco Borga ◽  
Giuliano Di Baldassarre ◽  
Anthony Patt ◽  
...  
Keyword(s):  
Risk Reduction ◽  
Flood Risk ◽  
Communication Strategies ◽  
Protection Motivation ◽  
Protective Measures ◽  
Risk Reduction Behaviour ◽  
Current State ◽  
Risk Areas ◽  
Avoidance Measures ◽  
Negative Impacts

Abstract. Private risk reduction behaviours can significantly reduce the negative impacts of flooding and flash floods. Over the past decades, researchers have used various socio-cognitive models or threat/coping mechanisms to explain individual protective behaviours. However, these models ignore that people are not equally ready to act upon a danger and they give limited insights into the effectiveness of communication strategies to foster risk reduction behaviours. Therefore, we explored the current state of homeowner's readiness to undertake risk reduction behaviours in flood risk areas by applying a dynamic protection motivation framework. We conducted a survey in an Italian municipality that experienced severe flash flooding in September 2018. The results show that people are motivated by different factors in prompting risk reduction behaviour based on their type of protective measures. For example, people that undertook structural or avoidance measures are more likely to be motivated to protect themselves by increased perceptions of vulnerability and response efficacy, and are less worried about expected flood losses compared to people that undertook only basic emergency measures. In this paper, we argue how these new insights contribute to target flood risk communication strategies to groups of individuals characterized by different readiness stages and motivations to protect themselves.

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