Kerala Flood Research Articles

Impact of urbanization on flooding in chalakudy river

Extreme events like floods are a concern for any country in terms of the damages caused to life as well as property. The recent trend of unpredictable rainfall in India leads to significant changes in the flow of the river and basin characteristics, which contribute to the aggravation of floods. In the cataclysmic flood in the year 2018 in Kerala, the Chalakudy river basin was completely inundated. This region has undergone extensive environmental changes since the 1990s due to agricultural expansion, deforestation, increased urbanization etc. These indicate the need for conducting a hydrologic and land use/land cover (LULC) change analysis to identify the causes, effects and solutions to mitigate the devastating effect of floods. This goal is achieved with the help of Geographic Information System (ArcGIS) and a hydrological model (HEC-HMS). The results from the study shows that tremendous change in land use pattern has occurred over the past few decades and the notable among them is the 1003.9% increase in built-up area. The increase in flood peak of the devastating Kerala Flood 2018, exclusively due to this land use change/urbanization is found to be about 22% in this study area.

A s tudy on new amphibious housing solution for vulnerable communities in Kuttanad

Face of Kerala is changing with climate making it more vulnerable to flood and flood related hazards. Flood hazard mitigation strategies requires a greater degree of adaptability, which calls for the development of new housing types that build resilience among vulnerable population. Kuttanad is a low-lying deltaic region in Kerala with highest number of flood displaced population per year. The economically weaker section of this region is striving for a flood resilient house. Huge house damage loss followed by Kerala flood 2018 paved the way to think about a construction that lives with water without making any obstruction to its flow. Amphibious housing is a sustainable flood mitigation strategy that works in synchrony with the flood vulnerable region’s natural cycle of flooding. These type of constructions are already a part of Netherlands and Rural Louisiana since 1970’s. This paper reviews the case studies of existing amphibious buildings globally and present flood resilient constructions of Kerala. It also analyses the possibility and proposed a new amphibious housing solution based on timber for the vulnerable regions in Kuttanad. The material selection was based on certain parameters which ensure the sustainability of prototype. These type of construction can act as a permanent housing solution for the flood displaced population of Kuttanad.

A Hybrid Approach of Machine Learning and Lexicons to Sentiment Analysis: Enhanced Insights from Twitter Data of Natural Disasters

The success factor of sentimental analysis lies in identifying the most occurring and relevant opinions among users relating to the particular topic. In this paper, we develop a framework to analyze users’ sentiments on Twitter on natural disasters using the data pre-processing techniques and a hybrid of machine learning, statistical modeling, and lexicon-based approach. We choose TF-IDF and K-means for sentiment classification among affinitive and hierarchical clustering. Latent Dirichlet Allocation, a pipeline of Doc2Vec and K-means used to capture themes, then perform multi-level polarity indices classification and its time series analysis. In our study, we draw insights from 243,746 tweets for Kerala’s 2018 natural disasters in India. The key findings of the study are the classification of sentiments based on similarity and polarity indices and identifying themes among the topics discussed on Twitter. We observe different sets of emotions and influencers, among others. Through this case example of Kerala floods, it shows how the government and other organizations could track the positive/negative sentiments concerning time and location; gain a better understanding of the topic of discussion trending among the public, and collaborate with crucial Twitter users/influencers to spread and figure out the gaps in the implementation of schemes in terms of design and execution. This research’s uniqueness is the streamlined and efficient combination of algorithms and techniques embedded in the framework used in achieving the above output, which can be integrated into a platform with GUI for further automation.

Social media and disaster management: influencing e-participation content on disabilities

PurposeThis study aims to analyse the nature and forms of digital content that may influence e-participation for persons with disabilities (PWDs) during a flood disaster.Design/methodology/approachThis paper undertakes a case study of the 2019 and 2020’s flood in Kerala, India. In-depth interviews with rehab workers during the flood are used in the study. Topic modelling and sentiment analysis are carried out using Twitter data. The native language responses from Facebook forums related to PWDs are analysed manually to construct taxonomy of problematic contentFindingsThe results show that problematic content toward PWDs in the social media occurs during a flood. The extreme and exploitative content results in disability exclusion. Thus, e-participants fail to address the actual disability-specific requirements through social media during a disaster.Research limitations/implicationsThe paper explores social media content toward PWDs. Implications of findings on citizens’ e-participation competency are delineated. Existing e-participation literature reports a low degree of disability e-participation in social media. Exploring disability e-participation helps to design more inclusive participation platforms. Further studies can explore the disability consciousness among e-participants for a more inclusive space.Practical implicationsThe development of problematic content in the social media environment is alarming. Regulatory frameworks are also less adequate. Hence, policies for enabling inclusive participation that is not limited to the information technology infrastructure is needed.Social implicationsFirst, the citizens will get more insights for meaningful disability e-participation. Second, inclusive e-participation platform designs will help to reduce problematic content generation.Originality/valueDisability e-participation requires regional studies. But there are fewer studies on disability e-participation from developing nations. The current study considered the regional context and complexities of disability e-participation. This paper gives policy recommendations for an inclusive e-participation.

Learned Helplessness, Psychological Wellbeing, and Proenvironment Care Behavior among Victims of Frequent Floods in Kerala

Background In 2018 and 2019, there were floods in the coastal regions of Kerala. Many individuals and families were victims on both these occasions; these floods had devastating impact on individual psychological wellbeing, their financial stability, and on overall family wellbeing. Furthermore, many people in vulnerable geographical areas still live in uncertainty and fear. In this context, our study examined whether continuous victimization of natural calamities, like floods in Kerala, leads to the development of learned helplessness and decreased psychological wellbeing among those affected. We also studied whether proenvironment care behavior increased among flood-affected individuals. Materials and Methods We studied 374 heads of families in Kerala, selected through the Quota sampling method. They belonged to the following three groups: (1) flood-affected only once (OFA, n = 124), (2) flood-affected twice (TFA, n = 124), and (3) never flood-affected (NFA, n = 124) households. The key variables of learned helplessness, psychological wellbeing, and proenvironment care behavior were measured using learned helplessness scale, psychological wellbeing scale, and the environmental behavior scale, respectively. Statistical Analysis The Kruskal–Wallis test was used to analyze the data for independent groups. Results Learned helplessness was found to be high among the TFA group. Psychological wellbeing and proenvironment care behavior were high among the OFA group as compared with the TFA group. The NFA group had higher learned helplessness in comparison to the OFA group, and psychological wellbeing and proenvironment care behavior were low when compared with the TFA group. Conclusion We conclude that surviving a moderate amount of risk is perhaps necessary for better psychological wellbeing and that too many or too few risks in life are detrimental to good psychological health. Immediate psychological support among victims of natural calamities and periodic examination of well-being and psychological interventions among people who are vulnerable for frequent victimization of natural calamities have to part of disaster management related to natural calamities.

Convectively-Coupled High-Frequency Atmospheric Waves Triggered Kerala Floods in 2018 and 2019

Floods have repeatedly battered the South Indian state, Kerala, as a result of the unprecedented heavy rainfall during Boreal Summers, in recent years. The state witnessed large departures from normal rainfall in 2018 and 2019. Previous studies have seldom adopted a systematic approach to understand the phenomenon responsible for the recurrent extreme events. Hence, this study, based on spectral methods, identifies a characteristic propagation of high-frequency equatorial waves in the atmosphere, which travelled from near tropical west Pacific to the east coast of Africa. These waves stimulated intense convection and ensured sufficient availability of moisture over the state, and are hence responsible for Kerala Floods.

Depression, anxiety, stress, and resilience among the primary survivors of natural disaster: A study with special reference to Kerala Flood

Background: Kerala, the southernmost state in India experienced the worst flood in its history, in August 2018. The disaster led its survivors to psychological trauma, along with several other impacts. Aims: The present study assessed the mental health status and level of resilience among the primary survivors in the postdisaster phase of Kerala flood, and the possible interlinkage of demographic factors with the study variables. Materials and Methods: The study has done on a sample of 50 primary survivors of flood selected using a purposive sampling method. Two rating scales-Depression Anxiety Stress Scale-21 and brief resilience scale-were used for collecting data, along with a sociodemographic information sheet prepared by the researcher, which was administered in a face to face interview with the participants. IBM SPSS software (version 21) was used for data analysis and statistical tests such as t-test, analysis of variance, and Pearson's correlation tests were used to interpret the data. Results: Results revealed the prevalence of depression, anxiety, and stress among the survivors in the postdisaster phase. Statistically significant difference was found in depression and stress scores in terms of education, where survivors with higher education showed lower stress and depression. Results also showed a comorbidity of depression, anxiety, and stress and a negative correlation between resilience and stress scores. Conclusions: The disaster had a significant impact on the survivors' mental health and need medical interventions to address it. The educational status and resilience level of the survivors are important determinants of postdisaster mental health.

Change detection based flood mapping using multi-temporal Earth Observation satellite images: 2018 flood event of Kerala, India

ABSTRACT The future projections of climate change envisage a global increase in extreme precipitation events and subsequent flooding. The reliable and rapid flood maps are the critical parameters in preparing the disaster management plans. This study demonstrated an effective flood mapping framework using freely available multi-temporal Earth Observation (EO) images, including C-band Sentinel-1A & 1B Synthetic Aperture Radar (SAR) images and optical WorldView-3 images, for analyzing the 2018 flood event of Kerala, India. Two Change Detection (CD) techniques, i.e. Ratio Index (RI) and Normalized Change Index (NCI) combined with semi-automatic thresholding are implemented on temporal descending pass SAR images for flood identification. For ascending pass SAR images, the statistical-based thresholding method is implemented. The results indicate that combined use of ascending and descending pass SAR images contributed to a better understanding of flood conditions. It is also inferred that the use of a pre-flood image can enhance flood area estimation and helps in minimizing the overestimation errors. The results also found that NCI outperforms RI for Kerala flood event. Flood area extracted from these techniques is plotted against the Indian Meteorological Department (IMD) rainfall datasets, which showed a similar trend. Field photographs and optical images are used for validation purposes.

Prevalence and factors associated with post-traumatic stress disorder among flood-affected adults in a panchayat in Ernakulam district in Kerala

Floods affected the state of Kerala following unusually heavy rainfall during the monsoon season in August 2018. Post-Traumatic Stress Disorder (PTSD) is the most common and debilitating psychological disorder among victims of floods or any other massive disaster. This study aimed to determine the prevalence and the factors associated with Post-Traumatic Stress Disorder (PTSD) among flood-affected adults in a panchayat in Kerala. In light of the looming threat of climate change, and with Kerala being especially prone to recurring floods due to its geographical location, there is an urgent need to assess the impact of floods on the psychological wellbeing of the residents of the state. To the best of our knowledge, this is the first study to investigate the occurrence of PTSD among the residents of Kerala following exposure to floods. Methods: This was a cross-sectional study undertaken in 100 households in a flood-affected community in Kerala. The PTSD Checklist for DSM-5 (PCL-5) was administered to diagnose PTSD. The intensity of flood exposure was measured using a checklist of ten factors. Results: The prevalence of PTSD was 22%. Loss of a relative, physical injury, and affliction with a physical illness were significantly associated with PTSD. A higher intensity of flood exposure was associated with a greater prevalence of PTSD. Conclusion: Our study demonstrates the high prevalence of PTSD following floods in Kerala and the need to conduct post-disaster mental health screening. It highlights those factors that may predict the occurrence of PTSD in the affected population. Recommendations are also put forward to mitigate the psychological impact of floods on the inhabitants of the state in the coming years.

Conceptualizing Smart Disaster Governance: An Integrative Conceptual Framework

The discourse of disaster governance is focused on the arrangements, relationships, and roles of the various actors involved in disaster governance. However, due to the lack of research on utilizing emerging technologies in disaster governance systems, this paper addresses the prospective benefits of utilizing Internet of Things (IoT) technologies in smart disaster governance systems. The authors employed a conceptual analysis of the previous research on disaster governance and utilizing IoT in disaster management. The basic concepts and constructs were abstracted from the literature to conceptualize a smart disaster governance system and its processes. As a result, six spheres were portrayed to form the characteristics of the smart disaster governance system, and an integrative conceptual framework for smart disaster governance was developed. The conceptual framework encompasses IoT technologies’ capabilities and disaster governance functions, in addition to the foreseen enhancements in disaster coping capacities and an overall rise in disaster resilience. A hypothetical case study was conducted to investigate the conceptual framework’s plausibility, and it showed a probable enhancement of the disaster governance of the 2018 Kerala floods if the smart disaster governance framework was utilized. This research provides a novel conceptualization of smart disaster governance. It can deepen the understanding of prospective benefits of integrating IoT technologies with disaster governance functions, contribute to disaster governance policy formulations, and construct a basis for future research on smart disaster governance for a sustainable society.

Framework for strengthening primary health care and community networks to mitigate the long-term psychosocial impact of floods in Kerala

Individuals who encounter disasters experience negative consequences across physical, mental and psychosocial domains. Impacts on mental health and psychosocial domains are more common, and last longer than physical health problems. In August 2018, the state of Kerala, India witnessed unprecedented floods that resulted in 483 deaths and significant loss of property and livelihood. Project “PARIRAKSHA” was implemented by the Government of Kerala, to mitigate the long-term psychosocial impact of the disaster. It has been one of the largest comprehensive post-disaster psychosocial project in India till date, aimed to benefit approximately 2 million people across 93 panchayats which experienced severe flooding and loss of life.This paper describes the detailed methodology of this project. In addition, the supplementary material includes the technical manuals that were prepared, and is freely accessible to personnel in disaster affected zones.Counsellors were newly appointed in all the primary health centres in affected panchayats to provide mental health and psychosocial support. Accredited Social Health Activists (community level health workers) undertook home-visits to ensure early case-detection. Medical officers’ in affected areas received booster training regarding pharmacological management of mental health issues. Multi-disciplinary mobile mental health teams were constituted to ensure availability of specialised mental health inputs locally.The project integrated additional mental health resource personnel, into the existing health care system. Existing health care personnel received training to improve competency in dealing with post-disaster psychosocial issues. This framework is expected to ensure early detection and intervention, thus facilitating timely psychosocial recovery of communities impacted by the floods.

Impact of 2018 Kerala flood on soil quality of soils of agro- ecological unit 4 in Pathanamthitta district of Kerala

Impact of 2018 Kerala flood on soil quality of soils of agro- ecological unit 4 in Pathanamthitta district of Kerala

Impact of 2018 Kerala Floods on Soil Erosion: Need for Post-Disaster Soil Management

Extreme precipitation events lead to flash floods, which can trigger soil erosion and landslides. While damages to infrastructure and livelihoods are rapidly assessed on economic terms, damages to natural resources are not estimated due to limited observation record. This study conducted an analysis using remote sensing data to estimate changes in soil erosion rates before, during and after the Kerala 2018 floods, based on the Universal Soil Loss Equation (USLE). The USLE was driven by multiple data including: in situ rainfall data from Indian Meteorological Department (to estimate rainfall erosive factor), soil maps prepared by Food and Agriculture Organization (to estimate the soil erodibility factor from the properties of soil that consists of the percentage of clay, loam and silt), digital elevation model (to estimate topographic slope and length) from Shuttle Radar Topography Mission and multispectral imagery (to estimate cover management factor and conservation practice factor) from Landsat-8 satellite. Data from these sources were analysed using a Geographic Information System (GIS) platform. Results indicate a state-wise average increase of 80% (31–56 metric tons ha−1 year−1) in soil erosion rate during the floods. Of the districts, Idukki showed the highest increase, of 220% and more susceptibility to soil erosion, which is in comparison with government survey records. Results show that the floods and associated erosion were not only due to the rainfall event but also due to the rapid change in land use and land cover, from natural to human settlements. Therefore, government agencies need to protect land cover and reduce unsustainable development in ecologically sensitive environments, which if managed properly can act as a buffer for soil erosion extremes in Kerala.

Role of Government in Ensuring Safe Drinking Water after a Natural Disaster - A Case Study of Kerala Flood

Floods are one of the major natural disasters, resulting in the contamination of drinking water sources such as ground water and drinking water. Kerala had an abnormally high rainfall during 1st June 2018 to 19th August 2018. It resulted in the heavy loss of life and many people were evacuated and nearly one sixth of the total population were affected. Contamination of drinking water by floods results in water-borne illnesses. Alappuzha district of Kerala was one of the worst hit districts by flood. Economically backward sections of the population are usually more affected by any natural disaster particularly flood. Hence a study was made on the socio-economic status of the flood affected people and role of government in ensuring safe drinking water. The water samples were collected from the ground water sources (wells) of flood affected Mannar panchayath of Chengannur taluk. The water quality of households affected due to flood were subjected to various physico-chemical and microbiological analysis. Also the quality of water collected from flood affected areas were calculated using two indices - WQI and OPI. Based on the results, the recommendations were made to improve the performance of the government in ensuring safe drinking water after a flood.

Promoting community participation in prophylactic measures against Leptospirosis following devastating floods in central Kerala: an exploratory study

Background: Community capacity is superior in Kerala, making the people identify, mobilize, and address public health problems. The state of Kerala in South India was devastated by the 2018 August flood with cumulative rainfall of 2307 mm, 41% above the average rainfall received. Community participation helped to restore health with minimal post-flood morbidity. This paper intends to demonstrate the role of community participation in prophylaxis against Leptospirosis.Methods: As a part of post-flood recovery activity to prevent communicable diseases, the health system sought community health volunteers, local teachers, and philanthropic organizations. Training was given to volunteers to do preventive measures like chlorination of well water, provide leptospirosis prophylactic drugs based on the guidelines and promote the use of boiled water as well as personal and environmental hygiene. The health workers supervised preventive activities in the areas designated to the volunteers. Medical officers visited random houses to ensure quality and gave necessary instructions. The health staff counseled those who were unwilling for preventive measures. Results: The activity resulted in low incidence of leptospirosis cases (n=13; Incidence <0.02) in the population. Conclusion: Community engagement was effectively utilized by the public health system in disaster mitigation and control during this flood.

SYNERGISTIC USE OF REMOTE SENSING, GIS AND HYDROLOGICAL MODELS FOR STUDY OF AUGUST 2018 KERALA FLOODS

Abstract. Remote sensing and hydrological models are one of the foremost tools for rapid and comprehensive study of flood hazards and disasters in any parts of the world. Current study is focused on severe 2018 Kerala flood, and is done using various remote sensing data, geospatial tools and combination of hydrological/hydrodynamic/topographical models. Flood mapping is done with pre and post floods remote sensing datasets. For pre-Flood analysis, Normalized Difference Water Index (NDWI) map was prepared on Google Earth Engine (GEE), using Sentinel-2 images for the period of Feb. 2017 to identify permanent water bodies. For post-Flood analysis, GEE was used to download the pre-processed and thermal noise removed Sentinel-1 SAR image for Aug. 9, 2018, Aug. 14 and Aug. 21, 2018 and flood maps were generated using this data. In addition to SAR data, probable flood inundation areas using topography-based flood inundation tool HAND (Height Above Nearest Drainage tool) was also utilized. Hydrological simulation was carried out for all 12 major river sub-basins of Kerala, where floods are reported. Indian Meteorological Department-Global Precipitation Measurement (IMD-GPM) gridded daily data is used as input meteorological data for hydrological simulations. The hydrological simulations results were verified using published Central Water Commission (CWC) reports and reservoirs data for India-WRIS. The hydrodynamic simulation was also performed for simulating the Idukki dam release data and flood condition in downstream areas. Overall, an integrated study and developed approach can be utilized by state and central water and disaster management agencies to develop flood early warning systems.

Interaction of a Low-Pressure System, an Offshore Trough, and Mid-Tropospheric Dry Air Intrusion: The Kerala Flood of August 2018

The present study examines the Kerala Flood Event (KFE, 15–16 August 2018, in India) that occurred along the west coast of India and resulted in ~400 mm of rainfall in one day. The KFE was unique in comparison to previous floods in India, not only due to the rainfall duration and amount, but also due to the fact that the dams failed to mitigate the flood, which made it the worst in history. The main goal of this study is to analyze and elucidate the KFE based on meteorological and hydrological parameters. A propagating low-pressure system (LPS) from the Bay of Bengal (BoB) caused the streak of plenty of rainfall over Kerala, the west coast, central India, and the BoB. Additionally, the upper-tropospheric anti-cyclonic system over the Middle East region inhibited a northward advancement of LPS. On the western coast of India, a non-propagating (with diurnal fluctuations) offshore trough was observed over the west coast (from Kerala to Gujarat state). Therefore, a synergic interaction between LPS, an intrusion of dry air in the middle-troposphere, and the offshore trough was the main reason for KFE. However, after around ten days, rainfall saturated the dam capacities; thus, the released water, along with the amount of precipitation on the day of the event, was one of the other possible reasons which worsened the flood over Kerala.

Community resilience mechanism in an unexpected extreme weather event: An analysis of the Kerala floods of 2018, India

Community actions have a significant role in disaster response. This study analyses the socio-demographic and satisfaction variables within community resilience in the context of the Kerala floods of 2018 and elucidates its gaps from the perspective of a developing country. The data from the self-administered questionnaire survey among the fishermen who were prominent amongst the first responders during this flood were analyzed using SPSS. Global literature was also reviewed to examine the status of community resilience and its effectiveness in holistic disaster management. This is an issue which has rarely been addressed in past studies from India. The results indicate that the majority of the first responder-fishermen had a primary educational background. They have participated in the rescue mission as groups without much previous experience, but felt high levels of self-satisfaction afterwards. These first responders were well aware of coastal disasters, but had limited exposure to disaster preparedness and mock drills. Although hampered by limited physical and financial resources, they could effectively utilize their social capacities during the disaster. The importance of bottom up approach in disaster management, comprising ‘Community-Based Disaster Risk Management’ (CBDRM) which can transform vulnerable communities to resilient communities is underlined in this study. The importance of the resilience of the local population, especially the fishermen community in local disaster response is highlighted, and the shortcomings in the current practices are identified. An attempt is also made to recognize and promote further potential through training, awareness and proper early warning.

GEE4FLOOD: rapid mapping of flood areas using temporal Sentinel-1 SAR images with Google Earth Engine cloud platform

The present state of the art technologies for flood mapping are typically tested on small geographical regions due to limitation of resources, which hinders the implementation of real-time flood management activities. We proposed a unified framework (GEE4FLOOD) for rapid flood mapping in Google Earth Engine (GEE) cloud platform. With the unexpected spells of extreme rainfall in August 2018, many parts of Kerala state in India experienced a major disastrous flood. Therefore, we tested the GEE4FLOOD processing chain on August 2018 Kerala flood event. GEE4FLOOD utilizes multitemporal Sentinel-1 synthetic aperture radar images available in GEE catalog and an automatic Otsu’s thresholding algorithm for flood mapping. It also utilizes other remote sensing datasets available in GEE catalog for permanent water body mask creation and result validation. The ground truth data collected during the Kerala flood indicates promising accuracy with 82% overall accuracy and 78.5% accuracy for flood class alone. In addition, the entire process from data fetching to flood map generation at a varying geographical extent (district to state level) took ∼2 to 4 min.

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