Climate change and environmental degradation are two of the most urgent matters facing humanity. Evidence from various studies suggests that climate-related events that are caused by meteorological changes are increasing in frequency on a global scale [1
]. Our global society perceives great danger [2
]. Extreme weather events such as hailstorms, thunderstorms, and lightning are on the increase [3
], with impacts that are increasingly visible and detrimental to human survival to varying degrees [4
]. Developing countries are vulnerable to extreme weather events arising from climatic variability, and these events cause substantial economic damage. With rising global temperatures, different types of natural hazards have become more significant in regions where previously they had not. Frequent natural disasters are also the result of rapidly changing climatic conditions [5
]. Over the past decade, developing countries have annually faced USD 35 billion in losses from natural disasters and particularly extreme weather events [6
]. However, extreme weather events are recognized to be one of the prime causes of natural disasters where the devastation level is sometimes beyond imagining [7
Much research has been internationally conducted on climate change-induced extreme weather events, their climatology, and the adaptive capacities of communities or regions. Most of this research reveals the causes and effects, and the climatology of these extreme weather events. There are several existing studies related to hailstorms and their occurrence with thunderstorms and precipitation, yet most concern the impact of hailstorms and insurance loss. Web et al. (2001) studied hailstorms climatology [8
], and Sioutous et al. (2009) studied the impact of hailstorms on agriculture, property, and infrastructure [4
]. Hailstorms are small-scale phenomena in which rain in the form of irregular ice balls are produced by convective clouds [8
]. Yet despite their small-scale, they are among the major weather threats that result in large economic losses to agriculture, property, and infrastructure [4
]. Climatological studies in China have included analyses of average patterns of hail using spatial and temporal scales [9
] and an investigation of hail insurance records and hailpad data [10
]. There is insufficient understanding regarding the future potential impacts of hailstorms on sustainable agriculture and the ways to minimize losses from the storms.
Bangladesh is one of the most natural disaster-prone countries in the world [11
]. Nearly every year, it is affected by floods, tropical cyclones, storm surges, coastal erosion, thunderstorms, and droughts that cause significant loss of life and property, and jeopardize development activities [12
]. The frequency of occurrence of these disasters are increasing because of the impact of climate change [13
]. The degree of natural disaster damage depends on country location [14
]. Bangladesh is ranked fifth in the Global Climate Risk Index in a ranking of 170 countries that are most vulnerable to climate change [15
]. The least developed countries like Bangladesh are going through their most vital challenges associated with climate change and variability owing to their robust economic reliance on natural resources and rain-fed agriculture [16
]. The intensification of climate change and the proliferation of extreme events are resulting in major, detrimental impacts on Bangladesh’s agricultural sector outweighing impacts on its other economic sectors [17
]. Communities have developed coping mechanisms for more common disasters such as floods, droughts, and cyclones, and there are well-established government policies for support. There has been a lot of research in the coastal belt of southern Bangladesh, which is very vulnerable to climate change [18
], but only a few studies have been conducted in northern Bangladesh to investigate the impact of climate change induced extreme weather events, such as hailstorms, on crop production, livelihood, and sustainable agriculture. Whether hailstorms are accompanied by thunderstorms or not, they can cause significant damage to agriculture and render the marginal farmers of developing countries temporarily vulnerable to poverty [19
]. The impacts of these events also generate a period of food insecurity that sometimes continues throughout the year [20
Hailpads are used in many parts of the world to measure hail fall on the ground [21
], but as they are not used in Bangladesh, there are no specific data on the diameter of hailstones and kinetic energy of storms. The Bangladesh Meteorological Department (BMD) keeps data on three-hour intervals of rainfall and thunderstorms with or without hailstorms from its 35 weather stations. Moreover, the government’s National Disaster Plan (2016–2021) does not classify hailstorms as disasters; rather, only lightning is considered as significant among all extreme weather events. Due to the several disasters that hit the country every year, the government attempts to address disasters that have impacts over larger areas and are potential threats [22
]. The capacity to address extreme weather events such as hailstorms is restricted because of technical and resource limitations. Based on the data from the Bangladesh Ministry of Disaster Management and Relief (MoDRM), there are no policies that address hailstorm issues such as compensation to farmers or victims [23
]; in fact, hailstorms are recognized as temporal hazards based on their severity and distribution over the country. Their climatology, probability, threat, manageability, and severity impact the vulnerability of the sustainable agricultural sector, property, human health, and rural livelihoods, but these factors still remain unexplored. There is a significant lack of research regarding the place of communities in identifying and prioritizing different hazards. Hailstorms are generally regarded as usual hazards in Bangladesh, but their status and prioritization levels should be analyzed for further consideration. Hailstorms occur every year in Bangladesh, and the most destructive one occurred on April 14, 1986, killing at least 92 people in Gopalganj [21
], and damaging thousands of hectares of croplands.
Recently, farmers’ conceptions of hailstorm occurrence have changed due to the larger number of thunderstorms, and the storms do not seem to follow any regular temporal pattern [24
]. As there are different hazards in different seasons [25
], and these sometimes overlap each other with respect to severity and damage levels, it is sometimes difficult to discern how to prioritize and mitigate them [26
]. Northern Bangladesh is seriously affected by droughts and flash floods almost every year, and these result in a series of impacts on agriculture and livelihood issues [27
]. With hailstorms recognized as a more serious hazard in the region, it is important to know how they rank among the other frequently occurring hazards and how they affect sustainable agriculture. Numerous environmental disasters could result in farmers who cannot cope financially and lose motivation for crop production. They may quit agriculture if there is a high possibility of recurring hazards and compensation and incentives from government authorities are not made available. Where there is a greater hazard probability, it is more likely that farmers will quit farming, so it is important to look at the sustainability of agriculture. The lack of data on hailstorms in Bangladesh means this study is timely and significant. This study attempts to analyze both the current status of natural hazards with a focus on hailstorms, along with the vulnerability and risks to the community in order to help to formulate mitigation measures and improve policymaking. In addition, the study investigates the status of hailstorms in terms of their spatial and temporal distribution around the country.
This study was concerned with two important research objectives: Change in hazard prioritization and the exploration of the most significant hazard’s climatological status. The study found that hailstorms were the most significant hazard in the study area. This novel finding explains why farmers are deeply concerned about hailstorms, as they cause serious annual damage to crops at least once or twice a year. It was also reported that the frequency and distribution were increasing along with higher levels of devastation due to more intense hailstorms, larger sized hailstones, and longer storms. Climatology, frequency, and distribution were also shown, which answers the major research objective. Many researchers have conducted different types of research regarding Bangladesh’s existing and known natural hazards and analyses of their impacts. However, this study reveals the new knowledge that hailstorms have become the riskiest hazard in northern Bangladesh. There is almost no research on the frequency, intensity, and distribution of hailstorms specifically in Bangladesh, although there have been a number of studies instead found on thunderstorm climatology and its impact. The changes in the patterns of hailstorms, hailstone size, seasonal variation, important regions for hailstorms in Bangladesh, risks, vulnerability related to hailstorms, and farmers’ perceptions of hailstorms (in comparison to other potential hazards) have not been made clear from the previous researches.
There have been very few studies conducted on the frequency and distribution of hailstorm in Bangladesh. However, Yamane et al. (2009) studied the climatology of severe convective storms in Bangladesh, but did not specify hailstorms, which this study does [45
]. Habib (2012) [46
] found hailstorms and thunderstorms as a type 1 hazard in Bangladesh in general, where floods, riverbank erosion, and droughts were treated as type 2, and tsunamis and cyclones were considered as a type 3 [46
]. Hossain and Roy (2013) explored hailstorms as the fifth ranked hazard in community level risk analysis [47
], but this study showing a different result where hailstorm became the first ranked. Related to the findings of Dale et al. (2001) we can assume that the increasing number of hailstorms in northern Bangladesh, more particularly in the study area, could be induced due to the geographical location adjacent to the Himalaya mountains [48
]. Botzen et al. (2009) conducted research on climate change and hailstorm damage and opined that hailstorm frequency and damage could exacerbate in the future if temperature increases further due to climate change [49
]. Several studies have been made on thunderstorms over India, Bangladesh, and other countries [50
]. These studies are related to climatology, formation, structure, troposphere instability, and water vapor of the troposphere in association with the forecasting of thunderstorms, but almost no research has focused on hailstorms specifically due to the lack of data, or possible perception of this hazard as minor. BMD suffers from a lack of sophisticated data which are most important to understanding the climatology of hailstorms. This study presents a spatial map of hailstorms and found the most significant region in Bangladesh for occurrence and severity.
From the questionnaire survey, it was found that the occurrence of a single hailstorm in the study area could be disastrous, and every year they occur twice, thrice, or more. The data from the questionnaire showed that the farmers perceived that storm intensity, hailstone size, and kinetic energy are also gradually increasing, and those factors are causing serious damage to the study area. However, such data has not been officially recorded, which poses a major obstacle to further research. The risk of hailstorm was revealed to be the most significant of all natural hazards. Moreover, the data also showed that the farmers did not receive any incentive after hailstorms occurred regardless the consequences for crop production.
Malak et al. (2013) also applied the SMUG and FEMA models in their research to prioritize the hazards in Matlab, Bangladesh and found that flooding was the most important hazard in that locality and that hailstorms took the fourth position in the FEMA model’s analysis [33
]. Our study characterizes one of the parameters of the FEMA model, i.e., maximum threat as a threat to sustainable agriculture for the first time, exploring the relationship between hazards and the sustainability of agriculture. Ahsan et al. (2014) conducted a research on climate change and risk perceptions and found that the cyclone leads to substantive loss to the crop production, and 75% of farmers opined that if such disasters occur regularly, they will be compelled to quit farming [51
]. On the other hand, we found that almost all farmers perceived hailstorms as a potential threat to sustainable agriculture, and they might stop farming and choose non-farming income sources as mitigation strategies. This unique finding leads us to conclude that hailstorms are a big threat to sustainable agriculture in the study area. Accordingly, these models could be helpful in prioritizing hazards and assisting policymakers.
The frequency and distribution of hailstorms have gradually and significantly increased in the study area. The most important region for hailstorms in Bangladesh is the northern region, where different types of droughts are also having serious effects on agriculture. Flash floods were previously very common; however, the present scenario is different. Due to the change in rainfall patterns, good drainage facilities, and lower amounts of water in the adjacent river basin, flash floods are no longer regarded as significant hazards. Other extreme weather events are also increasing simultaneously with the changes in climate. Hailstorms have become the riskiest hazard in terms of their probability, damage level, and threat to sustainable agriculture in the study area. The SMUG and FEMA models finding clearly show that hailstorms emerged as the most significant hazard in the study area. There are few explicit policies that address the issues of hailstorms and agricultural compensation. Immediate attention should be paid to minimizing loss, and assistance should be given in the form of incentives, financial support, and/or farm input materials. Crop insurance would also help to compensate farmers. Assistance should also be given in choosing the most suitable plant varieties and cultivation practices, and in early harvesting of field crops to minimize the risk of hailstorm damage in the pre-monsoon season.
The major limitation of this study is its focus on a specific area of Bangladesh, so the result is localized rather than generalized. Therefore, future studies could consider the location and importance of hazards. We recommend conducting a deep climatological study of hailstorms to discover the reasons behind their higher frequency in the study area, as well as their vulnerability in a broader area, using a larger number of respondents. There is a limited field in the SMUG model that considers the damage level of a hazard, but it does not take the frequency into consideration. But integrated use of the SMUG and FEMA models overcome this limitation and provide satisfactory analyses for prioritization of hazards. In the changing global climate, the most vulnerable countries could adopt these models to prioritize the hazards and take action accordingly.