Impacts of cyclone and flood on crop and fish production in disaster prone coastal Bhola district of Bangladesh

This study assessed the impact of climate change induced disaster on crops and fisheries production at Bhola Sadar and Monpura upazila of Bhola district, Bangladesh during January to June 2018. The study was gathered primary data from primary observation (PO), questionnaire survey (QS), focus group discussion (FGD), and key informant interview (KII). Secondary data were collected from Upazila Agricultural Office and Upazila Fisheries Office of Bhola Sadar and Manpura upazila and moreover, climatic data were collected from Bangladesh Meteorological Department. Results of the study found that trend analysis indicates overall annual maximum temperature increased for Kharif-I, Kharif-II and Rabi season. Average annual minimum temperature also increased for Kharif-I season but decreased for Kharif-II and Rabi season. Study also found that for all cropping season average relative humidity was increased. Annual average rainfall exhibited decreasing trend for Kharif-I and Rabi season but increased for Kharif-II season in (1990-2019) time period. The Aus, T. Aman, Boro and Mung bean was dominant cropping pattern in Kharif-I, KharifII and Rabi season in Bhola district. Overall, Aus rice production in Kharif-I season increased but in 2009, 2013 production was decreased because of cyclone Aila (2009) and Cyclone Mahasen (2013). T. Aman production hampered due to Cyclone Sidr (2007) and flood (2014) in Kharif-II season. In Rabi season Boro rice production lessen because of low rainfall and salinity intrusion. Overall, Mung bean production increase but in 2008 and 2009 production become hampered due to late cultivation because of Cyclone Sidr (2007). Fish production rate increase in Bhola specially Hilsha fish because of non-climatic factor like raid in non-fishing time, banned current net but fish production in pond become diminished due to infrequent natural disaster. Practicing of salt and flood tolerant varieties, floating bed vegetable cultivation, and mixed cropping system (mainly for Rabi season), enhanced expedition activities against catching mother Ilish in prohibition period, dredging in the heart of the river which can eventually reduce vulnerabilities and increase crop and fish production in the Bhola region.


Introduction
Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer (IPCC, 2007;IPCC, 2012). It is one of the most disputed global issues and considered as a prominent example of a negative environmental externality (Tol, 2009). Temperature rise, warming oceans, sea level rise, extreme events, ocean acidification are the major manifestation of climate change. Climate change is likely to hamper agricultural production in coming decades, particularly in low-income countries where adaptive capacity is limited. Consequently, farmers are losing their interest in rice and other winter crop cultivation due to recurrent natural calamities (Neogi and Erskine, 2017).
In Bangladesh population growth rate is 2 million per year, and with such a growth rate, the population will become 233.2 million by 2050 (Basak, 2010). To meet the demands of its growing population, an estimated 70% increase in rice production is required over the coming decades (IRRI, 1993). In Bangladesh 90% of the rural population are directly related to agricultural activities. Agriculture sector contributes to income and employment generation in Bangladesh (MoEF, 2009). The Agro-economic contribution is 20.83% of the Gross Domestic Product (GDP). The coastal region plays a vital role in the national economy. Agricultural crops are being influenced by seasonal characteristics and distinct climate variables such as temperature, rainfall, humidity and day-length (Gornall et al., 2010). Bangladesh is one of the most vulnerable countries to climate change because of its geographic location; flat and low lying topography; high levels of poverty; reliance of many livelihoods that are sensitive to climate change particularly agriculture and fisheries (CCC, 2009). Natural disasters such as flood, droughts, soil and water salinity, cyclone, storm surges etc. affect crops and fisheries production. Several studies indicated that climate is changing and becoming more unpredictable every year in Bangladesh (Basak, 2010;Kotir, 2011). For instance, two rounds of floods and devastating cyclone Sidr in 2007 and cyclone Aila in 2009 and other recurrent natural disasters caused intense damage in agricultural production (Basak, 2010).
The two upazilas namely Bhola Sadar and Manpura of coastal Bhola district are affected by several climatic hazards, so this area is referred to as the coastal tidal surge prone area (MoEF, 2009). Here almost every year, crops and fish production are hampered due to some climatic hazards. The main sources of income of this area include agriculture (63.91%) followed by fisheries production and fish export, especially Hilsha fish. Major crops are paddy, chili, wheat, mung bean, sweet potato, ground nut, betel nut, betel leaf and masur, whereas, extinct or nearly extinct crops are tobacco, jute, linseed and sugarcane (NDP, 2013). Bhola district struggles to provide sufficient food for a population over 17 million due to agricultural and fisheries damage and loss of production (Banglapedia, 2017).
Due to climate change and human activities, the river tends to erode and a number of locations face severe bank-erosion problem. However, the effects of climate change are already evident on the agro-ecosystem, agriculture and fisheries production at Bhola district. The purpose of the study was to assess the impacts of climate change on crop and fisheries production and aimed to: i) assess climate change associated natural disasters, ii) both past and present crop and fish production status, and iii) identify impacts of climate change induced disaster on crops and fisheries production.

Study area
The study was carried out in two upazila including Bhola Sadar (Kachia union) and Manpura (Manpura union) of Bhola district (Fig.  1). These two upazilas are situated in between 22°41ʹ24.65ʺN and 22°11ʹ59.24ʺN latitude to 90°37ʹ13.50ʺE and 90°57ʹ13.49ʺE longitude. The two unions under the two upazilas are selected for being extremely vulnerable to natural disasters like floods, cyclones, tidal surges, tornadoes, river erosion and salinity intrusion. River floods are the most common over here. Areas are frequently flashed out by tidal water and inundated during monsoon season (Banglapedia, 2017).

Data collection, processing and analysis
Data collection is the systematic process to gather and measure information from a variety of sources to get overall and accurate idea of an area of interest (Fig. 2). For this study, primary data was collected through observation, questionnaire survey, key informant interview (KII) and focus group discussion (FGD). The KIIs typically involved a one-on-one conversation between a research team member and a key informant. Questionnaire survey was carried out in two upazilas with 100 respondents who provided their perception about climate change impact on crop and fisheries production. The FGD involved 100 respondents from each union, which included 5 experts, 70 different professions living in disaster prone area, and 25 others. Secondary data for agriculture, fisheries, and disasters were collected from archives of government and nongovernment organizations and institutions, diaries, reports, related journals, and papers. The crop and fish production was measured in the unit of metric tons (MT). All data were processed and analyzed by using MS excel, Minitab, and SPSS software.

Results and Discussion
People's perception on climatic hazards Changes of climatic variables: The study found 86% of the respondents think that temperature is increasing, while 14% people provided no answer.
Only 2% of the respondents think that rainfall is increasing, but majority (78%) of them believed that rainfall is decreasing (Fig. 3). No one understood what humidity is and they did not give any answer. Impact of natural disaster: The main natural disasters in Bhola district include flood, storm, cyclone and salinity intrusion. The frequency of flood decreased but the intensity increased significantly (Karim, 2010;DMB, 2010). Due to geographical location, Bangladesh receives and drains out huge volume of upstream waters. Consequently, frequent floods cause devastating effects on people's livelihoods. In the rainy season, saline water ingress up to 10% of inland area, while in the dry season saline water reaches up to 40% inland area (Shamsuddoha and Chowdhury, 2007). According to the survey, 15% of the respondents said that salinity is increasing, whereas 16% identified river erosion as the severe natural disaster. On the other hand, 28% and 37% of the respondents think that flood and cyclone are the main disaster, respectively. Only 3% respondents mentioned about drought (Fig. 4). Impacts on livelihood: The 53% of the respondents said climate change has impacts on their livelihoods, 17% of them said it has no impacts, but 30% had no idea of impacts (Fig. 5). In Bhola 71% farms were affected by flood and 12% stored grains were damaged in 2009 flood (Hasan et al., 2014). Safety and injuries at sea are often associated with natural disasters such as floods and hurricanes, reducing the physical abilities of fisher folk to continue their livelihoods (Badjeck et al., 2010). Trend of average annual maximum temperature of the study area: It was revealed that maximum temperature was increasing with 0.04C per year in Kharif-I season. For Kharif-I season, the value of R2=0.44 means the variables are moderately fitted in the regression line. Study also found an increasing trend and the rate was 0.028C per year in the time span for Kharif-II. In Rabi season, maximum temperature trend indicate temperature rises with 0.015C per year within time period between 1990 and 2019 in our study area (Fig. 6). Shahid (2010) reported that average maximum temperature in Bhola increases 0.12C per decade. Trend of average annual minimum temperature of the study area: The trend of average minimum temperature exhibited an increasing trend with 0.009C per year from (1990-2019) for Kharif-I season, the value of R 2 =0.03 means the variables are very slightly fitted in the regression line. For Kharif-II season average minimum temperature are decreases 0.0044°C per year and in Rabi season average minimum temperature decreases 0.014°C per year in the 1990-2019 time period. Highest change of monthly average minimum temperature was found for Northern region in Bangladesh for maximum months, whereas lowest change for Southeastern region during the period of (1976-2008) (Basak et al., 2013). Year Kharif-I Kharif-II Rabi average minimum temperature are decreases 0.061% per year in the 1990-2019 time periods (Fig. 7). According to Rajib et al. (2011), humidity showed increasing trends in almost all the parts of Bangladesh except that the south west region which showed decreasing trend. It decreased up to 0.16%.
Trend of annual average rainfall of the study area: In Kharif-I and Rabi seasons the trend of average rainfall exhibited a decreasing trend with 1.07 and 1.18 mm per year in last thirty years but in Kharif-II season overall rainfall rates were increased in the (1990-2019) time period (Fig. 8).
A study by Shahid (2010) found that changes in precipitation over Barisal increased at the rate of 0.89, 1.23 mm in monsoon and pre-monsoon season and decreased at the rate of 0.45 mm per year post-monsoon season from  time period. Rimi et al. (2009) reported that the overall climate scenario exhibited an increasing trend of total annual rainfall at Satkhira, which was not statistically significant.

Major natural disaster
Bangladesh experienced 224 natural disasters between 1980 and 2018, causing damage of over US$ 16 billion (UNDP, 2006).This study found that cyclones and floods are the most common natural disasters in Bhola district (

Cropping pattern
A spatial and temporal arrangement of crops within a cropping year, largely determined by physical, biological, and socioeconomic factors. Bangladesh has three cropping seasons (Rabi, Kharif-I and Kharif-II) in a year (Table 2). Since rice is the major crop, it dominates the cropping pattern. In medium lowlands, mixed cropping of Aus and broadcast Aman is a common practice, while in deeply flooded lands, single cropping of broadcast Aman (deep water rice) in Kharif or Boro in Rabi is the common practice. Most of the farmers focus or practice sequential cropping and mixed cropping. Different varieties of pulses, vegetables practices are taking place instead of Boro rice. Study found Boro cultivation occurred in Bhola Sadar Upazila. But In Monpura upazila Boro cultivation replaced by vegetables and Mung bean because of soil salinity and low rainfall.

Crop production
Aus production in Bhola Sadar: According to Rashid and Islam (2007) droughts, floods, soil salinity and cyclones are the major climatic events that have affected agricultural production adversely. The highest production of Aus rice (  Boro production in Bhola Sadar: The characteristics of floodwater may be hampering Boro rice production. Instead of depositing silt that boosts soil fertility, floodwaters are now carrying more sands, which often turn the whole fields unusable for agricultural production (Chowdhury, 2002). Boro rice production was Mung bean production in Bhola Sadar: The maximum (23,430 MT) Mung bean production was found in 2014-2015 and lowest (19,350 MT) production was found in 2007-2008 (Fig. 14).
The cyclone Sidr (2007)  Mung bean production in Manpura: The Mung bean production was found to be highest (18,240 MT) in 2015-2016. The lowest (12,612 MT) production was found in 2009-2010 (Fig. 15). Due to cyclone Sidr and Aila in 2007 and 2009, the Mung bean crops was being late cultivated that caused of delayed to next crop cultivation and caused reduction of production. Farmers cultivated Mung bean or vegetables instead of Boro rice. More water was required in Boro cultivation but due to less rainfall and salinity in Rabi season high yield Mung bean varieties replaced Boro cultivation especially in Monpura Upazila of Bhola district.

Impact on crop production:
According to the study, 91% of the respondents said production increased because of high yielding varieties, fertilizer practice, pesticides use and mixed cropping pattern, etc. Only 3% said production decreased and 6% said that production was same as before (Fig. 16). Causes of increasing crop production: The 45% of the respondents believe that production was increased due to high yielding varieties, 22% said use of fertilizer in proper amount, 13% believe climatic condition is friendly for production, 12% mentioned about modern technologies and 8% said there were other reasons like training, incentives and high yield crop seed provided by NGO and government behind the increase in production (Fig. 17).
According to FGD, farmers cultivated mainly 4 types of crops, local Aus, Aman, Boro and Mung bean. Farmers and fisherman said their crop and fish production is increasing. But, Boro rice production is decreasing due to salinity intrusion and less rainfall. According to KII, salinity intrusion is increasing and low average rainfall in Bhola district caused of Boro production decreased in Rabi season. Annual fish production in Manpura: Overall, the highest production of fishes was in 2016-2017. During cyclones, water normally rise up to several meters and flash out fisheries and destroy other flora and fauna (Karim and Mimura, 2008). Due to cyclone Sidr in 2007, tidal surges adversely affected the pond fish culture. The study found that due to cyclone Aila and cyclone Mahasen in 2009 and 2013; pond or hatchery fish productions were decreased significantly in Monpura upazila (Fig. 19). But Overall Hilsha fish production was increased. Impact on fish production: The 82% of the respondents who were fisherman said production was increasing due to different government initiatives, while 13% said production was decreasing and 5% had no idea about changes in the fish production amounts (Fig. 20). Production Impact on fish species: The 53% of the respondents said they get mostly Hilsha fish in Bhola district, 35% said pond fishes are also abundant in Bhola and Manpura upazila, 7% respondents mentioned about shrimp, and 5% respondents said about other fishes that is also found in Bhola sadar and Manpura upazila (Fig.  21). Causes of increasing fish production: The 40% of the respondents said timely raids by the authority increased fish production. Whereas 11, 23 and 25% of the respondents think that government initiative (like expedition against jatka fish catching, banned current net, provide incentive to the fisherman for not catching fish during spawning time of Hilsha), climatic condition and all of these factors, respectively were behind the fish production increased (Fig. 22).

Fig. 22. Causes of increasing production
According to FGD and KII, fish production is increasing because of strict rules, raid and other activities conducted by fisheries and government authority. The government has set 4 fish sanctuary and prohibits catching of fish from 1st November to 31st May and catching of mother Hilsha from 15th October to 24th October. These initiatives ultimately leading to increase in fish production in Bhola district.

Conclusions
Climatic variables are changing over time that leads to natural disasters. The impacts of frequently occurring natural disasters on crop production are evident in the coastal region of Bangladesh as well as in the study area. The Aus, Aman, Mung bean production is increasing, while Boro production is decreasing. Initiatives provided by agriculture extension office such as provision of high yielding varieties; adoption of salt resistant variety, proper training, manure application, incentives, and mixed cropping pattern are the main reasons behind increased crop production. The study finds that fish production is also increasing in both upazila of Bhola district. The reasons may include government initiatives like raid in restricted time period in the year, laws on prohibiting harmful fish net, provision of incentives during nonfishing period, proper training among fisherman, etc. However, recurrent and severe natural disasters as a manifestation of climate change impact may hinder and reduce productions despite of currently successful government initiatives.

Recommendation
Farmers can increase crop production by using proper fertilizer, insecticide and by using good quality seeds. So, Agriculture Extension office can take actions extensively to disseminate the message to the farmers about the benefits of high varieties. Proper operation of embankments should be ensured for protecting agriculture, fish culture in ponds from saline water, storm surges and floods. Changes should be brought into the whole farmers community about cropping pattern, more be focused on mix cropping pattern and priority on HYV cultivation in the cyclone affected areas. Governmental organization like fisheries department, coast guard and other organization can take expedition activities during non-fishing periods and they should also rising up expedition activities by banning harmful net to protect jatka fish. Develop climate-forecasting system to reducing hazards.