The escalating salinity crisis in Bangladesh’s coastal region has impacted the lives of over 43 million inhabitants. The climate change impacts including increasing salinity levels, saline water intrusion into surface water and groundwater, have threatened the safe drinking water access of this coastal community. This study proposes a home based solar desalination device that uses solar energy to desalinate and purify water. The primary objective of this research is to assess the feasibility of the desalination device as a sustainable solution to the drinking water salinity problem for the coastal Bangladesh. To conduct this feasibility study, Khulna, one of the most salinity affected coastal districts, was chosen as study area. The research methodology began with comprehensive field surveys using participatory research methods to understand the social acceptance towards the solar dealination device. Utilizing questionnaire surveys, Focus Group Discussions (FGD), Key Informant Interviews (KII), resource mapping and data collection on water usage, socio-demographic characteristics, and perceptions related to existing water quality, a holistic overview of the study area was obtained. The results from the field visits and market research indicated an urgent need for cost-effective water desalination technologies tailored to the marginalized coastal communities. Based on the results, about 68% of users expressed satisfaction after using solar desalination devices. The results of the study indicated the potential of solar desalination as a promising solution to the salinity issue.
“Climate change” has become a buzzword in this 21st century. We all probably know there are researchers and environmentalists trying to raise their voices against it and trying to make us aware its dreadful consequences. But the first question is, are we still fully aware of the true meaning of climate change? In simple words, climate change refers to the changes or variations in our climatic pattern that persist for a longer period of time, typically decades or more. Now the most crucial question comes here: are we really prepared for the world we are gradually moving towards due to climate change? Let alone facing all the challenges, are we even prepared enough to face the upcoming challenges only on “water”? Water being one of the most essential components of our environment, comprises about 71% of the earth’s surface, among which 97% being salt water and 3% being fresh water. In this 3% fresh water, about 2% is stored in icecaps and in glaciers, so they aren’t really usable; only 1% is available as a form of groundwater and surface water. This 1% of fresh water is utmost important for our daily life as we use regularly it for our household, industrial and agricultural purpose. But unfortunately, this is going to be the sector that will be heavily impacted by climate change which can be catastrophic for human existence. So, adaptation, resilience and preparedness have no alternative to encounter the upcoming challenges we are going to face.
Starting from the global perspective, the world temperature has increased alarmingly for the past few decades due to climate change. According to the NOAA 2019 Global Climate Summary, the combined land and ocean temperature has increased at an average rate of 0.07°C or 0.13°F per decade since 1880 but the average rate of increase since 1981 is 0.18°C or 0.32°F which is more than twice than the previous. This abrupt increase in temperature is affecting in many parts of the water cycle. In one hand, the precipitation pattern is turning the environment into an extreme one and on the other hand, it is melting the polar ice which is rising the sea level alarmingly. Some part of the world will have more precipitation and some part of the world will become drier. The countries receiving more precipitation will face challenges in stormwater management and also will have threats of floods and waterlogging where the drier countries will face droughts and water scarcity to meet the water demand for their agriculture and industries. In this process, the economically poorer countries will suffer the most for the access of safe water for drinking, sanitation and daily use. Taking U.S. as an example, the northern, midwest and central parts of U.S. are expected to have an increase in the intensity and frequency of heavy precipitation events where west, southwest, and southeast parts are expected to receive a decrease according to a study of Peterson (2013).
Figure: Precipitation change in U.S (source: Peterson et al. 2013)
This changing trend in precipitation will increase imbalance in supply and demand of water for daily uses which may create water stress in U.S making people suffer to access. According to a study from Michigan State University, up to 40.9 million American households may not be able to afford water and wastewater services in 2022 because of climate change.
Now, coming to the regional perspective, predictions are there that Asia will face the hardest hit by climate change in comparison to other continents. By 2050, parts of Asia will experience rise in average temperatures with lethal heat waves, extreme precipitation events and natural disasters like cyclones, drought, floods, hurricanes etc. As Asia has more residents in coastal cities than to all the other cities of the world, the negative impacts of sea level rise will be faced the most in Asia. According to Center for Strategic and International Studies, the 50-70 centimeter rise in sea levels is expected by the end of the century which will threaten the 77% of Southeast Asians who live along the coast or in low lying river deltas. By 2050, predicted average annual flood levels will inundate the homes of over 79 million people in Southeast Asia. Also, about 3.4 billion people in Asia could face water stress by this time. A report by the Australian Water Partnership in 2019 found that water quality in India, Thailand and Vietnam is degrading due to the flow alteration in Himalayan and Mekong rivers. Moreover, the warming climate will melt a significant amount of Tibet’s glaciers in the next 75 years which will affect the water quality of many major rivers of Asia. Overall, these reasons will exacerbate water insecurity throughout the region specially to the poor countries. According to the McKinsey & Company’s Climate risk and response in Asia report, countries with low per capita GDP like Bangladesh, India, and Pakistan and emerging Asia like Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Thailand, and Vietnam are in most vulnerable condition from the impacts of climate change. Moreover, this increasing water scarcity will intensify the geopolitical competition and conflicts across this region over the regional water resources management issues like sharing of transboundary river water or construction of dams and barrage at the upstream of a river.
Now, focusing to the Bangladesh perspective, it needs to be mentioned at first that being a low-lying delta with exposed coastal area and having socio-economic factors like high population density and poverty, Bangladesh is one of the handful of countries that are at the highest risk of climate change. According to the 2020 edition of Germanwatch’s Climate Risk Index, it ranked seventh in the list of countries that are most affected by climate calamities during 1999–2018. As a low-lying delta with such a huge population in the coastal cities, it can be disastrous for us if the sea level continues to rise because of climate change. According to Bangladesh Climate Change Strategy and Action Plan 2008, the sea levels in Bangladesh are predicted to rise by up to 0.30 metres by 2050 which may result in the displacement of 0.9 million people in the coastal belt. Moreover, the increasing salinity in coastal region is creating problems in agriculture and access of pure drinking water. According to Soil Resources Development Institute (SRDI), Ministry of Agriculture, Bangladesh, over the last 35 years, salinity has increased to 26% within the country. Previously, salinity affected land was 83.3 million hectares in 1973 in Bangladesh which increased to 102 million hectares in 2000 and 105.6 million hectares in 2009. However, Bangladesh will also struggle to have their part of share of the major rivers as the upstream of maximum rivers are situated in India, Nepal and China. Failure to negotiate in transboundary water issues with India, Nepal and other neighboring countries can intensify the water scarcity thus create problems to meet the agricultural and industrial water demand. Where the scarcity of water will be high in dry season, on the other hand, the increasing trend in precipitation indicate that Bangladesh will fall victim of frequent floods during monsoon in future. Thus, storm water management issues will be crucial in the upcoming future to prevent waterlogging and drainage congestion. The government of Bangladesh is trying to focus on these upcoming challenges and with a vision of sustainable management of water resources, the Delta Plan 2100 was launched in 2018.
Last but not the least, because of climate change, we are gradually moving toward a world that is not desirable to any of us. We need to acknowledge that climate change and its impact on water is a global issue and the whole world is at risk due to it. Thus, to combat the negative impacts of climate change and to have a sustainable world, we all need to be come forward to form policies and strategies to save the world.
Sabrina Rashid Sheonty
Salinity of water is another name of suffering for the southern coastal community of Bangladesh. The community frequently faces severe natural calamities due to the geographical location of the region. The recent cyclones Sitrang (2022), Jawad (2021), Amphan (2020), Fani (2019) are evidence of that. When the cyclones strike, the salinity intrusion increases in the surface and ground water sources of the nearby areas. Intrusion of saline water causes the salinity which impacts drinking water, agriculture and many social and economic aspects of life of coastal community. For understanding the salinity level with clarity, the entire coastal region of Bangladesh may be divided into four distinct geo-morphological zones. The southwest zone contains the Sundarbans and it is surrounded by the Baleswar River in the east, and the Raimongal River in the west. The Gorai River is the main source of freshwater for this zone. The boundary of southeast zone starts from the Feni River to Badarmokam having the Lower Meghna River as the western boundary of this region. The south-central zone is situated between the southeast zone and southwest zone that receives considerable freshwater from the Padma River and the Lower Meghna rivers. The Eastern-Hill zone is in the Chittagong and Cox’s Bazar Districts with several flat beaches comprised of clay and sand. In this region, the Karnaphuli, Matamuhuri, Sangu, and Naf Rivers discharge freshwater through the plain. This region. At present, the rivers of the southwest zone suffer mostly from salinity intrusion among the four coastal zones. A groundwater salinity map of the coastal part of Bangladesh was prepared by Bangladesh Agricultural Development Corporation (BADC) using salinity observation wells data where it is evident that the south-western zone is the highest saline water zone.
Figure 1: Salinity concentration in groundwater at the coastal part of Bangladesh (BADC, 2011)
The salinity is the terms that refers to the salt content dissolved in water. The general predominant ions in the water are sodium and chloride, and the substantial concentrations of ions are magnesium, calcium, and sulfate ions etc. In 2003, a technical report prepared by WHO and the FAO recommends not taking more than 5 g sodium chloride (or 2 g sodium) per day, while ensuring that the salt is iodized. But recent research shows Sodium concentrations above 1000mg/l surrounding the high-moderate south western salinity zone of Bangladesh. Acute salinity and impurity in the drinking water has already affected 43 million people of Bangladesh. The financial condition has worsened the situation for people living under the poverty line. They are compelled to consume saline water regularly of which pasts the danger level. Consumption of saline water over the years can cause serious long-term health issues. There are evidences for the relationship between excessive salt intake and cardio-vascular disease, such as heart disease, strokes and high blood pressure. In case of pregnant women, excessive salt intake can cause gestational hypertension and (pre)eclampsia which can end up in maternal death.
According to Soil Resources Development Institute (SRDI), Ministry of Agriculture, Bangladesh, over the last 35 years, salinity has increased to 26% within the country. As per the 2020 edition of Germanwatch’s Climate Risk Index, Bangladesh is ranked seventh in the list of countries that are most affected by climate calamities during 1999–2018. The salinity amount is expected to increase in near future as a result of climate change which can be catastrophic for coastal community living at that region. Some researches show that the aquifer saline zone may increase by 2.27% by 2050 and fresh water zone will decrease by 3.44%. As a result, severe salinity zone is expected to increase by 14% by 2050.
Last but not the least, we need to acknowledge that salinity and its impact on southwest coastal community is a serious issue which is going to be amplified in near future. Thus, the government and non-government institutions need to be come forward to find solutions and adaptation strategies for it.
