Sectoral Impacts of Flash Flood in Tanguar Haor in Sunamganj of Bangladesh

Sunamganj is a most affected and the people were mainly suffered from cold and fever (98.13%), diarrhoea (80.63%), typhoid (27.5%), and dysentery (33.13%), respectively because of the crisis of pure drinking water and poor sanitation system. About 85% respondents stored normal food, followed by dry food (30%), medicine (25%) and water (0.63%), respectively to meet up post-flood food crisis. 62% respondents received flood warning signals by mobile phone (54.37%) followed by, radio/TV (41.87%), relatives (41.25%) and Upazila/Union Parisad (13.75%), respectively. However, various initiatives were taken by GOs and NGOs to build back a better immediate post-flood period. Finally, it is suggested that proper long-term steps should be taken to strengthen resilience and coping capacity for hydrological disasters in the study area.


INTRODUCTION
The riverine floodplain (almost 80%) Bangladesh is one of the largest deltas in the world [1] encompasses sub-tropical monsoon rainstorm climate. The main river system is the Ganges-Brahmaputra-Meghna (GBM) alongside in excess of 210 tributaries and distributaries convey an immense volume of downpour runoff [2] and thus 20.5% areas of Bangladesh affected by flood [3]. The north-eastern part of Bangladesh is a low-laying bowl-shaped depression containing many wetland areas, locally known as haor. The district of Sunamganj, also located in this part, has unique physiography. A total of 461 wetlands are available in Bangladesh [4,5] among them the Tanguar Haor (Ramsar Site) is the largest one that situated in the Sunamganj district [6]. This haor supports 56000 to 60000 inhabitant's livelihoods from 46 to 88 villages which contribute to national food security [4,7,8,9,10]. This haor is extremely rich fisheries resources with a total of 200/140 [10] wetland plants and 141 fish species [9,11]. Community people living in this haor area rely upon a single pattern crop (boro rice) yearly that contributes significantly to the national rice production [1] and 80% agricultural land covered with boro rice [4]. However, the people of the haor areas of Sunamganj District are most vulnerable to early flooding also to extreme monsoon and postmonsoon flash floods. Flash flood is considered as the main disaster in the haor area which inundates the primary production sector and threatens the lives and livelihoods of the people [12]. Globally, hydro-meteorological hazards e.g., flash flood pose a direct threat to human lives and it has severe impacts on livelihoods e.g., homestead property, water infrastructure and sanitation facilities, damages to crops, and the socio-economic condition as well [13].
There are several factors mainly influence to occur flash flood e.g., excess rainfall in the upstream hilly areas and subsequent runoff, sedimentation in the rivers, deforestation and hill cuts, landslide, improper drainage, unplanned road and water management infrastructure and the effect of climate variability [12]. When the sudden rise of water level in the upstream reaches of rivers ultimately causes flash flood in their downstream branches and tributaries since these narrow meandering rivers fail to contain the billowing flow from upper reaches. However, the flood management work is done by the Bangladesh Water Development Board (BWDB). The government has also decided not to allow any developmental or commercial activity within the haor area, which is harmful to haor environment. Besides, the government has banned the digging of wells for gas or oil within the 10 km area of the haor [10]. The objectives of this study were to find out the causes behind the flash flood and impacts on transportation, agriculture, housing, health and sanitation sectors.

Data Source
The data was collected from six randomly selected villages of this union named Golabari, Joypur, Islampur, Silan, Tahirpur, and Torong. This study used the secondary data were collected from journals, books, and organizations such as Bangladesh Water Development Board (BWDB), Upazila Agriculture Office (UAO), Bangladesh Bureau of Statistics (BBS), etc.

Sample Size and Data Collection
A total of 162 households were evenly targeted and a semi-structured self-explorative questionnaire was used to collect primary data from six selected villages. Households were selected randomly, and heads of households were interviewed for the study. Another six focus group discussions (FGD) were performed from six villages in the study area. The questionnaire was developed based on research objectives and agricultural, transportation, health, housing, water, and sanitation sectors. The duration of the primary data collection was June-August 2019.

Occupation
Agriculture (82.5%) is the main occupation in the study area, followed by, fishing (8.13%), business (6.87%), poultry farming (2.5%), respectively. They grew only robi crops in their cultivable lands and boro was the staple crop. It was also cleared from the study area that community people did not rely on the single occupation for their livelihood but many of them were involved in multi-occupational activities.
The result also showed that 41% of people migrated for their livelihood. Usually, in the wetland areas, occupational change, and deterioration of the quality of life are identified as key the impacts [14]. Due to season-based occupation and lack of availability of capital, poor and landless people migrated to Dhaka (capital city) or Chattagram (commercial city) in monsoon to find alternative jobs in construction works, brickfields, a rickshaw puller, day labor, etc.

Educational qualification
The study revealed that the literacy rate was 29.38% and the rest of the respondents were illiterate. Among the literate respondents, 18.75% passed the primary school certificate (PSC), followed by 6.25% junior school certificate (JSC), 2.5% secondary school certificate (SSC) and only 1.88% higher secondary certificate (HSC) examination, respectively.

Family size
The family size of each household was 6.28 and the district average family size was 5.58 [15].

Microcredit Provided by Local NGOs
Women in haor area have access to microcredit provided by local NGOs. They took loans for mainly three reasons to rebuild their houses; to feed family members just after disasters, and to repay loans taken from other sources. Households in these community plunged into vicious cycle (poverty cycle) of asset loss and money lending or microcredit due to income instability. In the study area, the majority (74%) respondents took microcredit and 26% did not take it. The result showed that annually 55.08% respondents took BDT10000-20000, followed by BDT21000-30000 (23.73%), BDT31000 (7.63%), BDT41000-50000 (5.93%) and above BDT50000 (7.63%), respectively (Fig

Causes of Flash Flood
Flooding in any area varies regarding the changing the base level of river elevation [13] and 80% of respondents' [2] of the study area was the victim of flash flood 1-2 times in a year. The survey resulted that there were many factors responsible for causing a flash flood in the study area. The study results indicated that heavy rainfall (92.5%) and low land (53.13%) were the main causes of flood, followed by an increase of river water (36.25%), lack of management (34.38%), upstream water (34.38%), and sedimentation on riverbeds (19.38%), respectively (Fig. 4). It is showed in a of 28 years rainfall analysis that 80% of total annual rainfall occurred during May- 58 2.5 acres), medium 5.0 acres) and large (>5.0 acres). The study result showed the distribution of the land of the households' that the majority (71.88%) was functionally landless, followed by marginal (16.87%), small (8.75%) and medium (2.5%),

Microcredit Provided by Local NGOs
area have access to microcredit provided by local NGOs. They took loans for mainly three reasons to rebuild their houses; to feed family members just after disasters, and to repay loans taken from other sources. Households in these community plunged into the vicious cycle (poverty cycle) of asset loss and money lending or microcredit due to income instability. In the study area, the majority (74%) respondents took microcredit and 26% did not take it. The result showed that annually 55.08% 20000, followed by 30000 (23.73%), BDT31000-40000 50000 (5.93%) and above (Fig. 3).
Flooding in any area varies regarding the elevation [13] and 80% of respondents' [2] of the study area 2 times in a year. The survey resulted that there were many factors responsible for causing a flash flood in the study area. The study results indicated that heavy rainfall (92.5%) and low land (53.13%) were the main causes of flood, followed by an increase of river water (36.25%), lack of management (34.38%), upstream water (34.38%), and sedimentation on riverbeds (19.38%), . It is showed in a study [2] of 28 years rainfall analysis that 80% of total -October.

Sectoral Impacts of Flood in the Study Area
Flood deteriorates the usual activities of life, affecting housing, infrastructure, agricultural land, transportation, water supply and sanitation system and these are severely affected. The study revealed that transportation (84.37%) and agricultural (82.5%) sectors were most affected by a flash flood, followed by water and sanitation (60%), housing (51.25%) and health (36.62%), respectively (Fig. 5).
The study revealed that during flood all the sectors had been damaged but agricultural land may be fertile because of sediment deposition. The result also cleared that the transportation and agricultural sector were severely damaged due to the flash flood.

Agricultural sector
The respondents of the study area grew crops once a year. The study showed that (82.5%) is the main robi crop, followed by vegetables (44.38%) jute (5%) and potato (1.25%), respectively. After robi crops, cultivable land became fallow round the year. In the study area, most of the lands were low land and flooded every year especially in the monsoon season. The study showed that 94% of respondents told agricultural land was affected/flooded most during the flood and only 6% of respondents' land were not flooded because these were homestead area. The result also revealed that 90.23% of respondents totally lost their agricultural crops and 9.77% of respondents partially lost their agricultural crops. After the flood, a lot of problems had risen. Most respondents (83.75%) told that they faced seed problem, followed by the increased price of seed (63.75%), increased labor cost (52.5%), shortage of money (35%), lack of tractor (2.25%), lack of fertilizer (1.25%) and unusable agricultural land (1.25%), respectively (Fig. 6).

Agricultural land ownership status of the respondents
; Article no.AJGR.67982

Sectoral Impacts of Flood in the Study
Flood deteriorates the usual activities of life, affecting housing, infrastructure, agricultural land, transportation, water supply and sanitation system and these are severely affected. The study revealed that transportation (84.37%) and agricultural (82.5%) sectors were most affected by a flash flood, followed by water and sanitation %) and health (36.62%), The study revealed that during flood all the sectors had been damaged but agricultural land may be fertile because of sediment deposition. The result also cleared that the transportation or were severely damaged The respondents of the study area grew crops once a year. The study showed that boro crop, followed by vegetables (44.38%) jute (5%) and potato crops, cultivable land became fallow round the year. In the study area, most of the lands were low land and flooded every year especially in the monsoon he study showed that 94% of respondents told agricultural land was affected/flooded most during the flood and only 6% of respondents' land were not flooded because these were homestead area. The result also revealed that 90.23% of respondents totally their agricultural crops and 9.77% of respondents partially lost their agricultural crops. After the flood, a lot of problems had risen. Most respondents (83.75%) told that they faced seed problem, followed by the increased price of seed d labor cost (52.5%), shortage of money (35%), lack of tractor (2.25%), lack of fertilizer (1.25%) and unusable agricultural land

Annual financial agricultural losses
Most of the households (HHs) have annual financial losses during the flood. It depends on the frequency and duration of the flood. Agricultural land is inundated severely which may vary depending on the intensity and duration of the flood. The study found that annuall HHs had no losses because they might not involve in agricultural activities or their land may higher elevation than others, followed by 20.63% lost <BDT10000, 16.84% lost BDT11000 16.21% lost BDT21000-30000, 10% lost BDT31000-40000 and 15% lost >BDT41000, respectively (Fig. 7).

Annual financial agricultural losses
households (HHs) have annual financial losses during the flood. It depends on the frequency and duration of the flood. Agricultural land is inundated severely which may vary depending on the intensity and duration of the flood. The study found that annually 21.25% HHs had no losses because they might not involve in agricultural activities or their land may higher elevation than others, followed by 20.63% lost <BDT10000, 16.84% lost BDT11000-20000, 30000, 10% lost lost >BDT41000,

Transportation sector
In every year, the transportation sector was severely affected by the flash flood. The result revealed that 84.37% of respondents told this sector was fully damaged and the rest of the respondents told this sector was partially damaged. Among these, 47.49% opined that village roads were submerged through floodwater, followed by roads were unsuitable to communicate (23.66%), unavailability of vehicles (28.85%), respectively. In contrast, 78. respondents used boats to transport different goods, passengers and other necessary things followed by cart (15.39%) and van (6.35%), respectively.

Respondents opinion on different sectoral impacts in the study area
In every year, the transportation sector was severely affected by the flash flood. The result revealed that 84.37% of respondents told this sector was fully damaged and the rest of the pondents told this sector was partially damaged. Among these, 47.49% opined that village roads were submerged through floodwater, followed by roads were unsuitable to communicate (23.66%), unavailability of vehicles (28.85%), respectively. In contrast, 78.26% of respondents used boats to transport different goods, passengers and other necessary things followed by cart (15.39%) and van (6.35%),

Housing sector
Flooding affects people in a multitude of ways. The survey showed that majority of the respondents (74.44%) said that homestead area was damaged by the flood period every year, followed by the respondents said that animal husbandry (33.13%) and homestead garden (23.13%) were also damaged by the flood time in the study area.

Health sector
The flood-affected people suffered from different communicable diseases like diarrhoea, dysentery, skin problem, cold and fever, etc. In the study area, acute shortage of pure drinking water and lack of sanitation arrangements were responsible for waterborne diseases because most of the households used floodwater without proper purification or treatment. The study result showed that 98.13% respondents told cold, and fever was the most common disease during the flood, followed by diarrhoea (80.63%), typhoid (27.5%), dysentery (33.13%), and others (3.75%, such as pneumonia, malaria, etc. (Fig. 8).

Water and sanitation sectors
Most of the tube-well was submerged either partially or fully, river and pond water were polluted; as a result, safe water became scarce in rural Bangladesh during flood time. The survey found that most of the people used deep tubewell (88.13%) water before the flood as a source of drinking purposes. They also used river water (74.37%), rainwater (1.87%), and pond sand filter water (3.13%), respectively (Fig. 9). So, the drinking water crisis was increased post-flood period. The sanitation system also hampered during this time and increased water-borne diseases. The study also revealed that 73.56% of respondents were told, their sanitation system was destructed completely, followed by partially (21.44%) and not destructed (5%).

Capturing flood forecasting and warning system
Bangladesh Water Development Board (BWDB) is liable for flood management through structural and non-structural measures and provides hydrological services in Bangladesh. It has been providing flood forecasting and warning services through its Flood Forecasting and Warning Centre (FFWC). Each administrative level committee is ready to monitor it [1]. The result revealed 62% of people received warning before the flood and 38% did not receive it. The study found that among the warning received people 54.37% of respondents received the warning by mobile phone, followed by 41.87% from radio/TV, 41.25% from relatives and 13.75% from Upazila/Union Office, respectively (Fig. 10a).

Food Storing Status during the Flood Period
The prices of food increased during the flood and it deteriorated food consumption, especially for the rural poor both in quality and quantity, and eventually leads them to malnutrition and health problem. So, storing food is essential for the local people to adapt during the flood period.
According to the survey result, 86% of respondents stored food and 14% of respondents did not store food during flood periods because they had no ability to adapt them for facing food scarcity. Among them, 85% of respondents claimed that they did not store any dry food, but they stored normal food (daily necessary foods), 30% stored dry food (chira, muri, gur etc.), 25% stored medicine and only 0.63% stored water for emergency need (Fig.  10b).

Post Water Purification Status
The study survey resulted that 34.55% of respondents drank water without purification during and after the flood, followed by 55.78% purified by boiling and 4.76% purified by using medicine or potash alum (Fig. 11). As a significant percentage of the respondents consumed water without purification process so, they suffered from various water-borne diseases.

Government and NGOs Initiatives for the Restoration of Flood-affected People
Government and NGOs play a vital role in the restoration of the flood-affected people in haor areas. Every year government provides recovery incentives for farmers, such as providing subsidized or free fertilizer and high yield seeds. They provide varieties of types of relief and commodities. The study result revealed that 76.87% of respondents said that the Government and NGOs took initiative immediately after the flood for the restoration of affected people and they received at least any one type of relief. The perception about sector wise initiatives is taken by the government and NGOs were tabulated below in the study area (Table 1).

CONCLUSION
The streams in the Tanguar haor flashy, low-lying topography with high annual rainfall and a flash flood occurs pre period that is vulnerable to different sectoral impacts. The vast extent of water bodies and prolong the duration of submergence has made the area difficult for human settlement. Due to flash flood, a thousand hectors of agricultural land were destroyed, and the food crisis occurred around the haor basin area every year which led to negative impacts on national food security.
The study results showed that children and women were most affected during the flood time.
Warning media for flood forecasting and food storing status flood water purification system for consumption haor are naturally lying topography with high annual rainfall and a flash flood occurs pre-monsoon period that is vulnerable to different sectoral impacts. The vast extent of water bodies and prolong the duration of submergence has made ficult for human settlement. Due to flash flood, a thousand hectors of agricultural land were destroyed, and the food crisis occurred basin area every year which led to negative impacts on national food security. that children and women were most affected during the flood time.
So, proper health care and sanitation facilities should be ensured by installing sanitary latrines and tube wells. Moreover, this research demonstrated that about 90.23% of respondents totally and 9.77% of respondents partially lost their agricultural crops. About 83.75% of respondents faced seed problem and 63.75% of respondents faced the increased price of seed in the post period of the flood. Most about 84.37% of respondents t transportation sector was destroyed and the communication was not possible without the boat and it was the largest sectoral impacts of floods. Therefore, it is essential to maintain transport system through the year and act carefully to minimize the lost. Hence, flood forecasting and roper health care and sanitation facilities should be ensured by installing sanitary latrines and tube wells. Moreover, this research that about 90.23% of respondents ly and 9.77% of respondents partially lost their agricultural crops. About 83.75% of respondents faced seed problem and 63.75% of respondents faced the increased price of seed in the post period of the flood. Most importantly, about 84.37% of respondents told the transportation sector was destroyed and the communication was not possible without the boat the largest sectoral impacts of floods. Therefore, it is essential to maintain transport system through the year and act carefully to lood forecasting and early warning were very important to reduce livelihood vulnerability. Long term record of impacts in different sectors can project the loss of future. So, this study can be helpful for the research of long-term flood impacts in different sectors. The flood cannot be fully controlled, prevented or eliminated, but damages should be reduced by taking preventive measures and coordination among different agencies or organizations. As climate change will have acute negative impacts on different sectors, short, medium and long-term initiatives would be taken to consider better livelihood and well-being for humans.

CONSENT
As per international standard or university standard, respondents' written consent has been collected and preserved by the author(s).