Disastrous Floods Research Articles

Linking climate change adaptation and disaster risk reduction: reconceptualizing flood risk governance in Mumbai

ABSTRACT Climate-related hazards, urban development and changing vulnerability patterns compel cities across the world to deal with new and emerging forms of risk. Academic literature and recent international policy documents suggest potentials of conceptually and practically linking the fields of climate change adaptation (CCA) and disaster risk reduction (DRR) and emphasize the need to mitigate climate-related risks at local level. However, there is limited knowledge on how this link is established at local levels and the role of ground-level actors and practices therein. Using the case of recurrent and disastrous floods, this paper discusses the significance of linking DRR and CCA in Mumbai. It analyses policies, plans, institutions and interventions related to DRR and CCA and uses interviews and a field study to assess flood risk governance at the level of municipal wards and neighbourhoods. The findings suggest that although flood risk governance has been significantly strengthened, three gaps exist: First, a lack of a comprehensive plan for Mumbai that anticipates future risks and vulnerabilities and integrates CCA and DRR down to local level. Second, a lack of an overarching and decentralized institutional framework across sectors and scales that recognizes the multiplicity of formal and informal actors. Third, the potential of civil society and informal actors for disaster risk management and adaptation planning has not been tapped into sufficiently. The paper argues that potential exists to reconceptualize flood risk governance in Mumbai by focusing on future risks and vulnerabilities and by recognizing the work of informal actors like emergent groups at local level.

Water politics: disputes about the “Yellow River-Huai River diversion proposal” in the 1930s

ABSTRACT Between the Southern Song and the Republican era in China, the Yellow River recurrently changed its course and inundated the Huai River, often resulting in disastrous flooding and millions of refugees in the northern Anhui Province. In early 1933, those Anhui natives living in Tianjin sent a communication to their countrymen back home, informing them that the Construction Bureau of Henan Province was contemplating a plan to divert the Yellow River into the Huai River via northern Anhui Province. This news brought wide-spread panic to northern Anhui and triggered two-year long disputes concerning the relevant proposal. At the time, both the Nanjing Nationalist government and the Henan provincial government insisted that the proposed project was only intended for local irrigation purposes, posing no risk to northern Anhui. As a matter of fact, “diverting the Yellow River into the Huai River” had long been an important plan for the Nationalist government. It was expected to improve the soil quality in eastern Henan province, increase the national tax revenue, relieve Henan Province of the perils caused by the Yellow River and develop the local irrigation system. Located in the middle and lower reaches of the Huai River, both Anhui and Jiangsu provinces had been the victims of the course-changing Yellow River and both provinces ought to have a common interest in questioning the desirability of the proposed plan by the Henan provincial government, or at least in theory. However, the officials of Jiangsu Province collectively chose to keep silent, concerned about national interests such as ensuring the implementation of the Huai River Diversion Project and the collection of the salt tax, as well as attending to local interests.

Estimating flood catastrophe bond prices using approximation method of the loss aggregate distribution: Evidence from Indonesia

Losses experienced by the Indonesian government due to floods are predicted. It is because of the significance of population growth, closure of water catchment areas, and climate change in many regions in Indonesia. The government has tried to reduce the risk but faces insufficient funds. Therefore, new innovative funding sources are essential to overcome these limitations. One way to obtain it is through issuing Flood Catastrophe Bonds (FCB). Unfortunately, Indonesia has had no FCB price estimate until now. On the basis of this problem, this study aims to estimate the FCB price in Indonesia. The primary method used is the approximation method of the aggregate loss distribution. This method can compute the aggregate flood loss cumulative distribution function value faster. The FCB fair price estimation results are cheap because the risk of the instrument is significant. This significant risk is also proportional to the large return. Finally, further analysis shows that in Indonesia, the attachment point of the FCB has a relationship that is in line with the price, while the term of FCB does not. This research is expected to assist the Indonesian government in determining the fair price of FCB in Indonesia. This research can assist the investors in choosing FCB based on expected return, attachment point, and the term they want.

Brewing epidemic of communicable diseases after massive flooding in Pakistan.

Brewing epidemic of communicable diseases after massive flooding in Pakistan.

Integrated Flood Risk Management Approach Using Mesh Grid Stability and Hydrodynamic Model

Today, inhabitants residing in floodplains face a serious and perpetual threat of flooding. Flooding causes fatalities and considerable property damage in metropolitan areas. Therefore, robust structural measures need to be adopted to eliminate flood catastrophe. Structural measures in the floodplain are the most promising solutions. However, there are cost-associated factors for proposing a flood retention plan. Navsari city (98.36 km2, area extent) of Gujarat was used as a case study to investigate the impact of mesh grid structures (100 m, 90 m, and 50 m) along with structural measures for the preparation of a flood retention plan. The HEC-RAS 2D hydrodynamic model was performed for the Purna River. The output of the model was characterized by four different scenarios: (i) Without weir and levees (WOWL), (ii) With weir (WW), (iii) With levees (WL), and (iv) With weir and levees (WWL). The statistical parameters (R2, RMSE, NSE, inundation time, and inundation area) were determined to evaluate model accuracy. The outcome of the model revealed that a 50 m size mesh grid exhibited more accurate results, yielding high NSE and R2 values (0.982 and 0.9855), a low RMSE value (0.450 m), and a smaller inundation area (114.61 km2). The results further revealed that the WW scenario was the most effective flood retention measure as it delayed the flood water for up to 16 h, and managed the flood with the WOWL case. Moreover, the mean error (WW scenario) estimated from profiles 1 and 2 ranged from (−0.7 to 0.62) and from (−0.1 to 0.02 m), respectively, which were evaluated as very low when compared with other scenarios. The novel scenario-based flood retention plan emphasizing the stability of mesh grid structures using the hydrodynamic model can be applied to any other region around the globe to recommend efficacious structural flood measures for flood decision making systems.

Establishing a co-design framework for disaster mitigation agenda in the urban context. A case study: SIBAT Solo

One of the impacts of climate change on the urban environment is the flood cycle which is significantly difficult to predict. Along with using engineering methods, one more effort that can be conducted is to prepare communities for flood catastrophes in order to address the problem of unpredictable floods in urban settings. The correct technique and approach should be employed to involve residents in a disaster mitigation system. The objective of this study is to provide a co-design framework to assist the agenda for reducing flood disasters in urban settings. The co-design technique is being utilized as a participatory strategy to perform the work objectives of the community-based disaster preparedness community in Solo, Indonesia, according to the preliminary study findings reported in this paper. This study employed a case study method of flood disaster mitigation practices by the SIBAT community. Data analysis administered the interactive model through three stages: data reduction, data display, and conclusion drawing. Preliminary results obtained indicate that the local social and cultural context is essential in developing a co-design framework. Therefore, these findings will later become the basis for building a co-design framework for implementing the flood disaster mitigation agenda in Solo

Floods and flood management and its socio-economic impact on Pakistan: A review of the empirical literature

Flood is one of the most damaging natural disasters as the recent floods have shown their serious impact on Pakistan. Flood control and regulation policies are essential to reduce the risks of economic downturn, a threat to human existence, and to sustain the ecology. The severity of flood catastrophe activities represents a constant and severe issue in the world. Floods are rising year by year in severity and duration, causing negative impacts on the social and economic conditions of the nation concerned. While the frequency of floods cannot be avoided, their adverse impacts can be considerably reduced by adopting careful planning and efficient training. This paper reviews the socioeconomic impact of floods, and the existing condition of flood control policies outlines the flood protection problems and discusses opportunities for successful and efficient flood control in Pakistan. The paper also intends to propose several suggestions for efficient and sustainable flood control in Pakistan.

Dengue surge in Pakistan amidst the torrential rains: The threat of a potential outbreak.

With 390 million infections occurring globally and the infection putting half of the world's population at risk, dengue is an illness with potential, life-threatening manifestations such as plasma leakage and fluid retention, severe bleeding, and organ impairment. This disease is already lurking in the various regions of Pakistan, which was recently ravaged by decades' worst flood. With mosquitoes being its eminent transmission source, it is coherent that a country with massive flooding, accumulation of stagnant water, and lack of adequate drainage systems can lead to a dengue outbreak. Pakistan, a low-middle-income country, is still recuperating from the aftershocks of the pandemic, a recent cholera outbreak, and the massive economic destruction they caused, especially in the healthcare sector. Concerningly, the World Health Organizationhas already issued a "second catastrophe" warning for Pakistan in the aftermath of the fatal floods which have caused the destruction of hundreds of health facilities while physicians and medical workers on the ground scramble to combat outbreaks of waterborne and other illnesses. If the spread of dengue isn't contained immediately, it will destroy the healthcare systems across the country and result in massive fatalities. To avoid tragic consequences, the government and concerned authorities must devise plans to launch public health programs aimed at boosting knowledge of the disease, its symptoms, transmission, prevention, and control. In this commentary, we discuss the current spike of dengue virus, epidemiology, transmission patterns, and preventative efforts in the aftermath of Pakistan's disastrous floods.

Participatory risk assessment of pluvial floods in four towns of Niger

Intense rainfalls in Sub-Saharan Africa are increasing in frequency. Land degradation, watercourses siltation, and flood defence failure turn these events into disastrous floods. Over the last decade flood risk assessments have been prepared to face these disasters. However, they have frequent limitations in design, accuracy, and completeness. The objectives of this study are (i) to integrate local and scientific knowledge into a participated pluvial flood risk assessment (ii) to identify assets and (iii) to estimate the potential impact and efficiency of risk-reduction measures. The assessment is developed in four rapidly expanding towns of Niger, flooded several times in recent years. Flood-prone areas and assets are identified according four flood scenarios using local knowledge, 2D hydraulic modelling, and visual photointerpretation of very-high-resolution satellite images. Risk-reduction measures are singled-out through public participation. The residual risk and benefit/cost analyses provide a decision-making tool to accept or treat risk. During the last decade the expansion of the four towns has been more rapid in flood-prone zones than in safe areas. Nowadays more than half of the housing stock could be flooded by rainfalls with 20 years return period. Catchment treatment and building retrofitting can reduce risk. from 100 to 29–82. Nevertheless, the benefit/cost of risk reduction is high for towns settled in small catchments only.

Smooth Spatial Modeling of Extreme Mediterranean Precipitation

Extreme precipitation events can lead to disastrous floods, which are the most significant natural hazards in the Mediterranean regions. Therefore, a proper characterization of these events is crucial. Extreme events defined as annual maxima can be modeled with the generalized extreme value (GEV) distribution. Owing to spatial heterogeneity, the distribution of extremes is non-stationary in space. To take non-stationarity into account, the parameters of the GEV distribution can be viewed as functions of covariates that convey spatial information. Such functions may be implemented as a generalized linear model (GLM) or with a more flexible non-parametric non-linear model such as an artificial neural network (ANN). In this work, we evaluate several statistical models that combine the GEV distribution with a GLM or with an ANN for a spatial interpolation of the GEV parameters. Key issues are the proper selection of the complexity level of the ANN (i.e., the number of hidden units) and the proper selection of spatial covariates. Three sites are included in our study: a region in the French Mediterranean, the Cap Bon area in northeast Tunisia, and the Merguellil catchment in central Tunisia. The comparative analysis aim at assessing the genericity of state-of-the-art approaches to interpolate the distribution of extreme precipitation events.

What could we have learnt from the previous flood data to predict losses caused by the 1980, 1986, and 1998 catastrophic floods in Ukrainian Transcarpathian?

This paper explores some aspects relating to retrospective predicting the confirmed monetary losses caused by the disastrous floods of 1980, 1986, and 1998 in the Tisza River basin within the Transcarpathian region of Ukraine. The research was based on two time series – the losses because of past floods and the maxima water discharges gauged at the hydrological station near the village of Vylok, Vynohradiv district. The main aim of the research was to make out whether it had been the possibility to predict the losses due to those floods in advance.In solving the task, there was revealed and modelled the dependence of the risk of losses due to the floods in Transcarpathia on the maximum water discharges of the Tisza River gauged at the “Vylok” hydrological station. Predicting was based on the hypothesis of the stationary random process for maximum water discharges, which allowed using an empirical distribution function of a random variable regarding flood water discharges assessing the risk of flood losses.Retrospective predicting of the losses caused by the floods of 1980, 1986, and 1998 was carried out by means of a combined situational-inductive predictive modelling method (CSIPMM), being an original author’s development. The method relates to predicting the behaviour of complex dynamic systems based on monitoring findings presented as time series data reflecting evolutions of a resulting (dependent) variable and an explaining (independent) variable (predictor). The method uses extrapolation-regression type models. According to this method, the prediction task is performed in two stages. The first stage realises the retrospective situational modelling task aiming to obtain a set of simple regressions (situational models) built on data of sample time series. The situational models are accepted to be adequate or relevant ones only within certain periods of time determined as situations. In the second stage, based on the generalization (on an ensemble) of the obtained retrospective situational models, inductive “levels” models are built, which reflect the behaviour of a controlled parameter of the system or process (a resulting variable) at several fixed values of a predictor in time. The inductive models are used in extrapolative predicting situational models belonging to future periods (situations).In total, three predictions were made: (1) taking into account the annual maximum flood discharges from 1954 to 1979 (before the flood of 1980); (2) the same from 1954 to 1985 (before the flood of 1986); (3) the same from 1954 to 1997 (before the flood of 1998). The study found that there had been a possibility to predict the confirmed monetary losses inflicted by the flood of 1986 and 1998 (relative predicting errors of 7.2-8.7% and 6.0-12.8% depending on the prediction options).

Study of Disaster Susceptibility and Economic Vulnerability to Strengthen Disaster Risk Reduction Instruments in Batu City, Indonesia

Batu City in East Java has a thriving tourist area, which is not exempt from disaster susceptibility and economic vulnerability. These weaknesses have led to the strengthening of the disaster resilience system becoming a priority in terms of the Batu government’s disaster risk reduction. The main objective of this study is to improve disaster risk management through the reinforcement of the disaster risk reduction instrument, which can improve the alertness and the mitigation capability of DRR. This research analyzed the susceptibility levels of five disasters—flood, landslide, drought, land fire, and COVID-19—using a quantitative method with panel data and a survey questionnaire. The influence variable was disaster susceptibility, which quantified economic vulnerability through ArcGIS and ILWIS analysis to generate the disaster susceptibility rate. Economic vulnerability was analyzed using static panel data in STATA/R, which generated the economic vulnerability index. The results of this research indicate that there are five villages in the high level of vulnerability category, three villages in the moderate level of vulnerability category, and another sixteen villages/urban villages in the low level of vulnerability category. Furthermore, static panel analysis found that local economic vulnerability in Batu is significantly influenced by three of the five disasters discussed in this research.

Mobility Disruptions in Accra: Recurrent Flooding, Fragile Infrastructure and Climate Change

This paper analyzes the mobility disruptions experienced by urban residents in relation to heavy precipitation and flooding of roads. The empirical focus is Accra, Ghana, a rapidly growing African city with discernible challenges in its transport system and a longstanding history of recurrent flood hazards, which are likely to be exacerbated by climate change in the future. In a context where there is very little mobility data available from official sources, the paper utilizes data from a large mobility survey (n = 1053) conducted through in-person interviews in July–August 2021 in 10 selected neighborhoods in Accra’s sprawling periphery. The survey targeted economically active adults, who are travelling regularly in relation to their income-generating activities. The survey recorded respondents’ experiences with a wide range of mobility disruptions caused by heavy precipitation and water on the roads. The analysis of survey data is supplemented with insights from qualitative interviews with a range of local key informants (n = 75). The research illuminates the diversity of mobility disruptions experienced by Accra’s residents during and after heavy precipitation events and the adverse implications for livelihoods and access to markets and services. The results highlight that mobility disruptions related to heavy precipitation are an extremely commonplace experience for residents in Accra’s periphery, across a diverse collection of neighborhoods and across travel patterns and traveler characteristics. While existing research tends to privilege the most dramatic and disastrous flood events and the associated destruction of property, this research, however, draws attention to the somewhat under-researched topic of mobility disruptions to everyday activities and their implications for livelihoods and access to markets and services.

Is There Singing in the Time of Crisis? Sounding Flood Songs of Coastal and Riverine Malabar in the Indian Ocean

This study examines the flood songs of Malabar written as performative literary texts in the Arabi-Malayalam language that were prevalent among the Muslim community of Malabar in the twentieth century. These songs were written as eyewitness accounts of the historical monsoon floods that afflicted the coastal regions and hinterlands of Malabar on the shores of the western Indian Ocean. Flood songs as a genre offer a combined understanding of ecology, religion and performance of the recurrent floods that occurred in twentieth-century Malabar. They also provide details about the importance of collective memorialisation and the commemoration strategies adopted to record the seasonal disastrous floods which still afflict the region. This paper puts forth two fundamental questions regarding flood songs: first, how did flood songs ideologically define and internalise the origins and causes of environmental disasters in an oceanic-riverine complex? Second, how did these songs aesthetically express the religious experience of the flood, adaptations to them, and ways of managing the risks they imposed? This study investigates the unique manifestations of spirituality, music/sound and nature and the environment in the flood songs of Malabar, topics which remain unexplored in academic literature.

Flood risk perception, disaster preparedness and response in flood-prone urban communities of Rivers State.

Rapid urbanisation is contributing to increasing societal vulnerability to disaster. This study aimed at exploring the perception on flood risk and ascertaining the determinants of disaster preparedness among residents in flood-prone urban communities. Descriptive statistics and discriminant regression model were employed on primary data collected from 240 urban households across five communities at risk of flooding in the study area. The results showed that most households had low awareness of flood risk and exhibit low levels of adaptive capacity, having adopted little or no measures to deal with disaster floods. Also, awareness of flood risk was observed to discriminate the most between the two groups of adopters and nonadopters of flood preventive and management measures (proxy for disaster preparedness), followed by flood risk perception, age, location and household size.ContributionThe study suggests an integrated approach (a combination of preventive, protective and control measures) by all stakeholders, including government and other relevant bodies, increasing public awareness of flood risk and its attending effects for greater responsiveness, supporting communities in regular clearing of drainage areas and strictly regulating the construction of buildings, particularly in flood prone areas.

Various health-related challenges amidst recent floods in Pakistan; strategies for future prevention and control.

Floods catastrophes are the most frequent hazards globally. According to the Center for Research on the Epidemiology of Disasters (CRED), a total of 432 catastrophic events were recorded in 2021, among which flood dominated with 223 occurrences alone. Flood catastrophes have significantly increased morbidity and mortality universally. It has made life more vulnerable in the context of numerous risks and calamities. During the flood, epidemics and outbreaks are most common affecting a larger population. People face various problems amidst floods like infectious diseases, reproductive health, and even mental health issues. Pakistan is currently one of the most frequently flood-affected nations in the world. As Pakistan continues to be devastated by monsoon flooding and torrential rains, 1290 people have died, 1,468,019 homes have been partially or completely destroyed, and 736,459 animals have perished. To plan an efficient health care program, it is crucial to know the common problems that frequently affect people during floods.

Management Options for Large Metropolitans on the Verge of a Water Stress

Karachi is the largest metropolitan area in Pakistan and houses about 14.91 million people (2017 census). It is the industrial hub and financial capital of Pakistan, but unfortunately, it is facing the worst water crisis in its history. Pakistan is bestowed with extensive water resources, but making use of them requires a paradigm shift in water policy and management. Karachi is facing a water crisis situation over the period of three decades, not due to the shortage of natural resources but to mismanagement on the part of the planners and managers, and the situation is getting worse with no imminent solution in sight. The present additional drinking water demand of Karachi has been estimated to be around 650 MGD (260+390) by the Karachi Water & Sewerage Board (KW&SB). This study accesses the water availability in surface water resources, i.e., the Indus River, in consideration of the requisite water demand of Karachi. There exists a mechanism for water transmission from the Indus River to Karachi at the Kotri Barrage. Being located at the tail of Indus, Kotri Barrage (last barrage before outfall into the sea) faces the two extremes in terms of system water availability: in wet season (monsoon), the system happens to be at the mercy of disastrous floods whereas, there is extreme water shortage during the dry months. In this paper, a sustainable water management plan has been devised for managing the additional water needs of Karachi throughout the year. The proposed plan recommends the diversion of additional flows from the Indus River at Kotri (from the water being wasted into the sea), and these flows have been routed through and stored in already existing infrastructure of the KW&SB, i.e., the Kalri Baghar Feeder Upper (KBFU) canal system and Keenjhar, Haleji, and Hadero Lakes. A further scenario-based integrated reservoir operation study presents the optimal use of available flows and storage capacities. In addition, filling and depletion mechanism of available storages has also been proposed and in all the analysed scenarios due consideration has been given to the environmental flows requirement of downstream Kotri riparian and irrigation indents of KBFU system. Hence, the proposed action plan ensures the availability of requisite flows to meet the drinking water needs of Krachi Metropolitan. Doi: 10.28991/HEF-2022-03-03-06 Full Text: PDF

Effect of cost–benefit perceptions on evacuation preparedness for urban flood disasters

Rapid urbanization and climate change have resulted in disastrous flood situations in Southeast Asia, and have caused considerable loss of life and property. To mitigate flood damage, evacuation of the area may sometimes be recommended. However, inhabitants' willingness and preparedness to evacuate flood-prone areas has yet to be investigated comprehensively. In this study, the factors that determine people's intention to prepare for evacuation in case of urban flood disasters are investigated by a questionnaire survey of people living in the Minato, Shinagawa, Meguro, and Ota wards located in the Jyonan area river basin of Tokyo. The results of the covariance structure analysis reveal that the higher the “interest in flood damage” and the “benefit perception” of evacuation behavior, the more people tend to consider evacuation preparation. Thus, the study results can be used to prepare strategies to mitigate flood damage in the future.

Climate Change Assessment on Flood Occurrence in Kota Tinggi, Johor

Flood is associated with the climatic change where the climate variable has detrimental impact on hydrologic cycle. Johor is among the affected states by flood catastrophe for almost every year. Over the year, Johor has experienced increasing amount of rainfall. However, studies on future rainfall pattern in Johor are still quite limited. Thus, this study was carried out to identify climate change impacts by projecting rainfall data using Statistical Downscaling Model (SDSM) and predicting flood events utilizing the Standardised Precipitation Index (SPI). Through SDSM, the rainfall data was projected in corresponding with General Circulation Models (GCM) predictor under three different representative concentration pathway (RCP) of RCP2.6, RCP4.5 and RCP8.5 that consider different emission level in future. Future observation in the upcoming 30 years for both studied stations at Kota Tinggi, Johor recorded increasing trend in the projected mean annual rainfall under three scenarios where the highest change in projection was +12.2% under RCP8.5 at Ladang Telok Sengat station. From SPI analysis, it is predicted that there will be frequent occurrence of flooding in the upcoming 30 years due to more positive SPI values (> 1) indicated by the studied stations. From the study, the authorities can come up with better mitigation plan to supervise the flood event in the future.

Application of MCDM methods for flood susceptibility assessment and evaluation the impacts of past experiences on flood preparedness

This research is analyzed the flood hazard using two ensemble models in ​​Mazandaran Province, Iran and assess how the experience contributed to community flood preparedness by household surveys. For this purpose, two approaches of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Attributive Border Approximation Area Comparison (MABAC) combined with Analytical Hierarchy Process (AHP) and weight of evidence (WOE) models were applied. Applying eight effective factors, including rainfall, distance from rivers, slope, soil, geology, elevation, drainage density, and land use, the flood risk zoning map was prepared with the help of Geographic Information System. The area under the receiver operating characteristic curve (AUROC) for test sample set was 87.14% and 83.24% for TOPSIS-based and MABAC-based models, respectively. Regression analysis found a negative correlation between past flood experience and flood preparedness of residents, consistent with cluster analysis. This indicates that local people had not learned much from previous experiences of flood catastrophes.