scholarly journals Spatiotemporal Flood Risk Determination and Management for a Large River Basin

2021 ◽  
pp. 92-106
Author(s):  
Nuanchan Singkran
Keyword(s):  
High Risk ◽  
River Basin ◽  
Flood Risk ◽  
Mitigation Measures ◽  
Environmental Damage ◽  
Risk Zone ◽  
Risk Indices ◽  
Risk Zones ◽  
Chao Phraya River ◽  
Very High

The Chao Phraya River Basin (CPRB) of Thailand faces flooding almost every year. The severest flood occurred in the CPRB in 2011 with the highest property damage costs (46.5 billion USD) and the highest casualty (813 deaths). The objectives of this study were thus to (1) determine flood risk indices and categorize them into four risk zones (low, moderate, high, and very high) across 994 sub-districts in the CPRB during the six rainy months (May–October); and (2) propose specific measures for flood risk management for each of the categorized risk zones. The flood risk indices were assessed as the product of two hazard variables (flood levels and monthly cumulative precipitation) and the vulnerability variable (land uses). The findings revealed spatiotemporal variations in flood risk. Spatially, the sub-districts deemed to be in the high or very high flood risk zone were mainly located close to the Chao Phraya River (CPR), where the flood levels reached 1.1 – 4 m in depth; whereas the sub-districts detected in the low or moderate flood risk zone were located further away from the CPR. Temporally, more sub-districts were detected in the high or very high risk zone in September when heavy rainfalls were observed. Specific measures are proposed herein to manage flood risk regarding the categorized zones during three periods. The preventive and mitigation measures should be prepared before flooding; emergency responses should be practically implemented during flooding; and the recovery after flooding should cover both infrastructural and environmental damage and mental/physical illnesses amongst the affected people. Intensive measures are recommended for the sub-districts located in both the high and very high risk zones. These measures may be properly loosened for the sub-districts located in the low and moderate risk zones.

scholarly journals Flood Risk Zoning of Satluj River Basin, Himachal Pradesh, India

2015 ◽  
Vol 40 ◽  
pp. 6-15 ◽  
Author(s):  
Sandeep Kumar ◽  
Santosh
Keyword(s):  
At Risk ◽  
Land Use ◽  
River Basin ◽  
Flood Risk ◽  
Low Risk ◽  
Risk Zone ◽  
Risk Zoning ◽  
Risk Zones ◽  
Satluj River ◽  
Very High

Increasing intensity and frequency of rainfall coupled with gradual retreating of glaciers due to climate change in Himalayan region likely to increase the risk of floods. A better understanding of risk zones which are vulnerable to flood disasters can be evolved from the detailed studies on slope, geomorphology and land use/ land cover pattern. Information of these parameters is an important input for the identification of vulnerable areas. Flood risk maps provide useful information about places that may be at risk from flooding. It offers a cost-effective solution for planning, management and mitigation strategies in risky areas. Traditional methods of flood risk mapping are based on ground surveys and aerial observations, but when the phenomenon is widespread, such methods are time consuming and expensive. The possible combination of DEM and other maps of area using an overlay operation method within the Geographical Information System (GIS) platform can lead to derivation and the understanding of spatial association between various parameters which could be used to predict flood risk zones. The study area i.e. Satluj River Basin has been broadly divided into five risk zones viz., very low, low, moderate, high and very high which helped to differentiate between areas that are at risk of different intensities of flood. The very high flood risk zone covers only 3.25 % of total study area, while the very low risk zone covers 13.63 %. The area falls within the very high and high risk constitutes 9.52 % of total basin area. Domain of moderate risk covers an area of 30.66 %. But the maximum area of river basin is constituted by low risk zone i.e. 46.19 %. Identification of such zones will help in timely adopting of mitigation and adaptation measures. Preparation of flood risk zoning maps also helps in regulating indiscriminate and unplanned land use practices in risky areas.

scholarly journals Multidimensional dynamic healthcare personnel (HCP)-centric model from a low-income and middle-income country to support and protect COVID-19 warriors: a large prospective cohort study

BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e043837
Author(s):  
Usha Dutta ◽  
Anurag Sachan ◽  
Madhumita Premkumar ◽  
Tulika Gupta ◽  
Swapnajeet Sahoo ◽  
...  
Keyword(s):  
High Risk ◽  
Low Income ◽  
Tertiary Care ◽  
Low Risk ◽  
Transmission Risk ◽  
Healthcare Personnel ◽  
Risk Zone ◽  
Increased Risk ◽  
Medium Risk ◽  
Risk Zones

ObjectivesHealthcare personnel (HCP) are at an increased risk of acquiring COVID-19 infection especially in resource-restricted healthcare settings, and return to homes unfit for self-isolation, making them apprehensive about COVID-19 duty and transmission risk to their families. We aimed at implementing a novel multidimensional HCP-centric evidence-based, dynamic policy with the objectives to reduce risk of HCP infection, ensure welfare and safety of the HCP and to improve willingness to accept and return to duty.SettingOur tertiary care university hospital, with 12 600 HCP, was divided into high-risk, medium-risk and low-risk zones. In the high-risk and medium-risk zones, we organised training, logistic support, postduty HCP welfare and collected feedback, and sent them home after they tested negative for COVID-19. We supervised use of appropriate personal protective equipment (PPE) and kept communication paperless.ParticipantsWe recruited willing low-risk HCP, aged <50 years, with no comorbidities to work in COVID-19 zones. Social distancing, hand hygiene and universal masking were advocated in the low-risk zone.ResultsBetween 31 March and 20 July 2020, we clinically screened 5553 outpatients, of whom 3012 (54.2%) were COVID-19 suspects managed in the medium-risk zone. Among them, 346 (11.4%) tested COVID-19 positive (57.2% male) and were managed in the high-risk zone with 19 (5.4%) deaths. One (0.08%) of the 1224 HCP in high-risk zone, 6 (0.62%) of 960 HCP in medium-risk zone and 23 (0.18%) of the 12 600 HCP in the low-risk zone tested positive at the end of shift. All the 30 COVID-19-positive HCP have since recovered. This HCP-centric policy resulted in low transmission rates (<1%), ensured satisfaction with training (92%), PPE (90.8%), medical and psychosocial support (79%) and improved acceptance of COVID-19 duty with 54.7% volunteering for re-deployment.ConclusionA multidimensional HCP-centric policy was effective in ensuring safety, satisfaction and welfare of HCP in a resource-poor setting and resulted in a willing workforce to fight the pandemic.

scholarly journals GIS-Based Climate Change Induced Flood Risk Mapping in Uhunmwonde Local Government Area, Edo State, Nigeria

2020 ◽  
pp. 8-23
Author(s):  
Obot Akpan Ibanga ◽  
Osaretin Friday Idehen
Keyword(s):  
Climate Change ◽  
Local Government ◽  
Flood Risk ◽  
Vegetation Index ◽  
Agricultural Land ◽  
Local Government Area ◽  
Risk Mapping ◽  
Risk Zone ◽  
Edo State ◽  
Risk Zones

Introduction: Flood is one of the climate change induced hazards occurring in most parts of the world. It exposes humanity and many socio-ecological systems to various levels of risks. In Nigeria, extreme rainfall events and poor drainage system have caused inundation of several settlements to flooding. To contain the disaster, risk mapping were among the measures recommended. Aims: The aim of this paper is to highlight flood risk zones (FRZ) in Uhunmwonde Local Government Area (LGA), Edo State, Nigeria. Methodology: Flood risk (FR) was mapped using hazards and vulnerability and implemented using geographic information system (GIS)-based multi-criteria analysis analytic hierarchy process (MCA-AHP) framework by incorporating seven environmental and two socio-economic factors. Elevation, flow accumulation, soil water index of wettest quarter, normalized difference vegetation index, rainfall of wettest quarter, runoff of wettest quarter and distance from rivers constituted the hazard component while population density and area of agricultural land use was the vulnerability layer. The climate change induced flood risk was validated using the responses of 150 residents in high, moderate and low flood risk zones. Results: The resulting flood risk map indicated that about 40.4% of Uhunmwonde LGA fell within high flood risk zone, 35.3% was categorized under moderate flood risk zone whereas low flood risk zone extended up to about 24.3% of the LGA. The high number of respondents who reported occurrence of flooding with frequency being very often and the fact that flooding was a very serious environmental threat during on-the-spot field assessment validated the generated climate change induced flood risk. Conclusion: The utilitarian capabilities of GIS-based MCA-AHP framework in integrating remotely-sensed biophysical and climate change related flood inducing indicators with socio-economic vulnerabilities to arrive at composite flood risk was demonstrated.

scholarly journals Forest fire risk mapping using analytical hierarchy process (AHP) and earth observation datasets: a case study in the mountainous terrain of Northeast India

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Ridalin Lamat ◽  
Mukesh Kumar ◽  
Arnab Kundu ◽  
Deepak Lal
Keyword(s):  
High Risk ◽  
Forest Fire ◽  
Analytical Hierarchy Process ◽  
Fire Risk ◽  
Control Measures ◽  
Fire Control ◽  
Risk Zones ◽  
Hierarchy Process ◽  
Forest Fire Risk ◽  
Very High

AbstractThis study presents a geospatial approach in conjunction with a multi-criteria decision-making (MCDM) tool for mapping forest fire risk zones in the district of Ri-Bhoi, Meghalaya, India which is very rich in biodiversity. Analytical hierarchy process (AHP)-based pair-wise comparison matrix was constructed to compare the selected parameters against each other based on their impact/influence (equal, moderate, strong, very strong, and extremely strong) on a forest fire. The final output delineated fire risk zones in the study area in four categories that include very high-risk, high-risk, moderate-risk, and low-risk zones. The delineated fire risk zones were found to be in close agreement with actual fire points obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) fire data for the study area. Results indicated that Ri-Bhoi’s 804.31 sq. km. (32.86%) the area was under ‘very high’ fire susceptibility. This was followed by 583.10 sq. km. (23.82%), 670.47 sq. km. (27.39%), and 390.12 sq. km. (15.93%) the area under high, moderate, and low fire risk categories, respectively. These results can be used effectively to plan fire control measures in advance and the methodology suggested in this study can be adopted in other areas too for delineating potential fire risk zones.

scholarly journals WILD FIRE RISK MAP IN THE EASTERN STEPPE OF MONGOLIA USING SPATIAL MULTI-CRITERIA ANALYSIS

2016 ◽  
Vol XLI-B1 ◽  
pp. 469-473 ◽  
Author(s):  
Elbegjargal Nasanbat ◽  
Ochirkhuyag Lkhamjav
Keyword(s):  
High Risk ◽  
Social Economic ◽  
Risk Index ◽  
Fire Risk ◽  
Low Risk ◽  
Moderate Risk ◽  
Validation Data ◽  
Risk Zone ◽  
Wildfire Risk ◽  
Very High

Grassland fire is a cause of major disturbance to ecosystems and economies throughout the world. This paper investigated to identify risk zone of wildfire distributions on the Eastern Steppe of Mongolia. The study selected variables for wildfire risk assessment using a combination of data collection, including Social Economic, Climate, Geographic Information Systems, Remotely sensed imagery, and statistical yearbook information. Moreover, an evaluation of the result is used field validation data and assessment. The data evaluation resulted divided by main three group factors Environmental, Social Economic factor, Climate factor and Fire information factor into eleven input variables, which were classified into five categories by risk levels important criteria and ranks. All of the explanatory variables were integrated into spatial a model and used to estimate the wildfire risk index. Within the index, five categories were created, based on spatial statistics, to adequately assess respective fire risk: very high risk, high risk, moderate risk, low and very low. Approximately more than half, 68 percent of the study area was predicted accuracy to good within the very high, high risk and moderate risk zones. The percentages of actual fires in each fire risk zone were as follows: very high risk, 42 percent; high risk, 26 percent; moderate risk, 13 percent; low risk, 8 percent; and very low risk, 11 percent. The main overall accuracy to correct prediction from the model was 62 percent. The model and results could be support in spatial decision making support system processes and in preventative wildfire management strategies. Also it could be help to improve ecological and biodiversity conservation management.

scholarly journals Assessment of Flood Risk in the Eastern Part of Jamuna Floodplain

2018 ◽  
Vol 44 (2) ◽  
pp. 211-224
Author(s):  
Maruf Billah ◽  
Mehedi Ahmed Ansary
Keyword(s):  
Flood Hazard ◽  
Emergency Situation ◽  
Mitigation Measures ◽  
Hazard Map ◽  
Individual Factor ◽  
Flood Vulnerability ◽  
Risk Zone ◽  
Hazard Vulnerability ◽  
Floodplain Area ◽  
Very High

Risk assessment provides the scope to understand the vulnerability situation of any area based on different hazard context. The study has been conducted in the eastern part of Jamuna floodplain area to examine its flood vulnerability. To perform the analysis, the whole study area has been surveyed and examined applying Geographic Information System. The entire hazard, vulnerability as well as the capacity factors are assessed and have been classified into different categories from very low to very high. Individual factor analysis has been considered to realize the specific condition of different factors. Finally, flood hazard map has been prepared to examine the vulnerability of the proposed area. This type of work helps the planners and disaster managers to identify the most risk zone which should receive immediate hazard mitigation measures as well as help to take a decision in an emergency situation when a flood may occur in the study area. Asiat. Soc. Bangladesh, Sci. 44(2): 211-224, December 2018

scholarly journals Flood Risk Assessment of Metro System Using Improved Trapezoidal Fuzzy AHP: A Case Study of Guangzhou

2021 ◽  
Vol 13 (24) ◽  
pp. 5154
Author(s):  
Guangpeng Wang ◽  
Lianyou Liu ◽  
Peijun Shi ◽  
Guoming Zhang ◽  
Jifu Liu
Keyword(s):  
High Risk ◽  
Flood Risk ◽  
Urban Areas ◽  
Fuzzy Ahp ◽  
Scientific Data ◽  
Risk Level ◽  
Analytic Hierarchy ◽  
Risk Levels ◽  
Metro Systems ◽  
Very High

Metro systems have become high-risk entities due to the increased frequency and severity of urban flooding. Therefore, understanding the flood risk of metro systems is a prerequisite for mega-cities’ flood protection and risk management. This study proposes a method for accurately assessing the flood risk of metro systems based on an improved trapezoidal fuzzy analytic hierarchy process (AHP). We applied this method to assess the flood risk of 14 lines and 268 stations of the Guangzhou Metro. The risk results validation showed that the accuracy of the improved trapezoidal fuzzy AHP (90% match) outperformed the traditional trapezoidal AHP (70% match). The distribution of different flood risk levels in Guangzhou metro lines exhibited a polarization signature. About 69% (155 km2) of very high and high risk zones were concentrated in central urban areas (Yuexiu, Liwan, Tianhe, and Haizhu); the three metro lines with the highest overall risk level were lines 3, 6, and 5; and the metro stations at very high risk were mainly located on metro lines 6, 3, 5, 1, and 2. Based on fieldwork, we suggest raising exits, installing watertight doors, and using early warning strategies to resist metro floods. This study can provide scientific data for decision-makers to reasonably allocate flood prevention resources, which is significant in reducing flood losses and promoting Guangzhou’s sustainable development.

High prevalence of multiple sclerosis in the Swedish county of Värmland

2009 ◽  
Vol 15 (11) ◽  
pp. 1253-1262 ◽  
Author(s):  
Inger Boström ◽  
Margarita Callander ◽  
John F Kurtzke ◽  
Anne-Marie Landtblom
Keyword(s):  
Multiple Sclerosis ◽  
High Risk ◽  
Epidemiological Studies ◽  
Southwestern Part ◽  
Risk Zone ◽  
Current Prevalence ◽  
High Prevalence ◽  
Average Annual Incidence ◽  
Prevalence Ratios ◽  
Very High

Previous epidemiological studies have indicated that the county of Värmland in western Sweden may be a high-risk zone for multiple sclerosis (MS). The objective of this study was to determine the prevalence in the area. Hospital and general practice medical files were scrutinized. The diagnostic criteria of Poser were used, with 31 December 2002 as prevalence day. The prevalence was 170.07 per 100,000 inhabitants. The average annual incidence was 6.39 to 6.46 per 100,000 (1991—1995, 1996—2000). Multiple sclerosis was 2.3 times more common among women than men. There was a variation in prevalence among the 16 municipalities, however it was not statistically significant. The rates seemed highest in the southwestern part of the county, roughly similar in location to findings some 70 years earlier. When the prevalence ratios by geographical units for the county in 1933 were applied to the current prevalence, the distribution from these estimated cases differed from homogeneity with very high significance (p < 0.00001 ). In conclusion, this study supports previous reports indicating that Värmland continues to be a high-risk zone for MS and shares in the diffusion of the disease at the county level which we had presented for the country as a whole.

scholarly journals Flash Flood Susceptibility Assessment and Zonation Using an Integrating Analytic Hierarchy Process and Frequency Ratio Model for the Chitral District, Khyber Pakhtunkhwa, Pakistan

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1650
Author(s):  
Hassan Waqas ◽  
Linlin Lu ◽  
Aqil Tariq ◽  
Qingting Li ◽  
Muhammad Fahad Baqa ◽  
...  
Keyword(s):  
High Risk ◽  
Frequency Ratio ◽  
Flash Flood ◽  
Drainage Density ◽  
Low Risk ◽  
Physical Parameters ◽  
Observation Data ◽  
Risk Zones ◽  
Hierarchy Process ◽  
Very High

Pakistan is a flood-prone country and almost every year, it is hit by floods of varying magnitudes. This study was conducted to generate a flash flood map using analytical hierarchy process (AHP) and frequency ratio (FR) models in the ArcGIS 10.6 environment. Eight flash-flood-causing physical parameters were considered for this study. Five parameters were based on the digital elevation model (DEM), Advanced Land Observation Satellite (ALOS), and Sentinel-2 satellite, including distance from the river and drainage density slope, elevation, and land cover, respectively. Two other parameters were geology and soil, consisting of different rock and soil formations, respectively, where both layers were classified based on their resistance against water percolation. One parameter was rainfall. Rainfall observation data obtained from five meteorological stations exist close to the Chitral District, Pakistan. According to its significant importance in the occurrence of a flash flood, each criterion was allotted an estimated weight with the help of AHP and FR. In the end, all the parameters were integrated using weighted overlay analysis in which the influence value of the drainage density was given the highest value. This gave the output in terms of five flood risk zones: very high risk, high risk, moderate risk, low risk, and very low risk. According to the results, 1168 km2, that is, 8% of the total area, showed a very high risk of flood occurrence. Reshun, Mastuj, Booni, Colony, and some other villages were identified as high-risk zones of the study area, which have been drastically damaged many times by flash floods. This study is pioneering in its field and provides policy guidelines for risk managers, emergency and disaster response services, urban and infrastructure planners, hydrologists, and climate scientists.

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