Planning and costing agriculture’s adaptation in Bangladesh: Deltaic, flood-prone cropping systems (rice)
Summary of country findings: Bangladesh
This study is one of 5 country studies (Bangladesh, Malawi, Nepal, Rwanda and Tanzania) exploring planning and costing agriculture’s adaptation to climate change. The agricultural system described was deltaic, flood-prone cropping systems, namely rice production in the lowlands at small and medium scales.
Bangladesh is a deltaic country of which 80% consists of alluvial sediment deposited by the rivers that combine in and flow out through the delta. Agriculture, forestry and fisheries contribute to 21% of GDP (YASB, 2005; 2008) and about a quarter of total exports, and employ just over half of the labour force (BBS Labor Force Survey, 200-03). Rice covers almost 75% of Bangladesh’s agricultural land and is the dominant crop in the coastal belt of Satkhira, Khulna and Bagerhat Districts, where this study focused. Agriculture, especially in the coastal zone, is subject to widespread salinity problems, which reduce agricultural output. These problems are expected to increase with climate change.
With a large and growing population, maintaining production in these marginal areas is crucial to food security goals. While a number of climate change hazards need to be addressed, this study has focused on those related to rising soil salinity levels, because of their particular importance to the agricultural system.
Currently 35% of Satkhira, 29% of Khulna and 36% of Bagherat are classified as either “strongly saline” or “very strongly saline” (above 8 dS/m), where crop production is almost nil, and an additional 5, 7, and 8% of land is “slightly saline” (4-8dS/m), where many crops find it difficult to survive.
Drivers of Salinity
Bangladesh experiences a cycle of saline intrusion and outflow through the year, with sea water flowing further into the delta during the dry season (November to May) which is then diluted out with fresh water during the wet season (June to October). Saline ground water also is brought to the surface during the dry season. Tidal action means low lying land is constantly inundated and uncovered. As salt water on land evaporates away the salt content is left behind.
Climate change is expected to change the hydrology of Bangladesh through several vectors further increasing the salinity in the soil. Sea level rise will result in salt water intruding further into the coastal zone and increases the probability of salt water overtopping protective bunds into fields. Sea level rise may also result in greater salinity in ground water sources, reducing the availability of freshwater for irrigation.
Changes in the timing and intensity of the monsoon are expected to result in a shorter but more intense wet season. Melting of snow and ice on the Himalayas will change the freshwater flows through river systems as will adaptation actions by India to store and utilise more of the water from the Ganges reducing freshwater flows to Bangladesh. Generally it is expected that salt water will intrude further into the country and the availability of freshwater for irrigation and to leach salt out of the soil will be reduced.
Agriculture in the coastal zone of Bangladesh has already adopted various measures to allow it to cope with existing levels of salinity. Bunds are built around fields to prevent salt water inundating them at high tide. Ponds called ‘khals’ are built around fields which capture freshwater when during the annual floods in the wet season. Khals allow farmers to release freshwater into their fields, releasing individual sections at a time, to flush out the salt that would otherwise build up in the soil. A system of drainage ditches allows brackish water from irrigated fields to drain away. Furthermore Bangladesh has been at the forefront of global efforts to breed varieties of rice that can still grow in saline soils.
Whilst some adaptation have already been adopted there is still currently a development and adaptation deficit; there is more which could be done to cope with existing environmental pressures. This deficit will be compounded by climate change. Existing methods for coping with salinity will have limits to their effectiveness if salinity levels rise too far. However currently there is still scope for expanding existing practices; limits have not yet been breached.
The study looks at two main adaptation signatures to cope with rising salinity. These are the development and deployment of saline resistant varieties; and improving irrigation, drainage and flood defense infrastructure to improve capacity to irrigate crops, leach out salt and protect against seawater intrusion. The study has looked at the types, scales and incidence of the costs involved with existing actions and attempted to estimate them as they are scaled up to cope with increased climate change induced salinity.
Saline Tolerant Varieties
There are multiple aspects to operationalising the use of saline tolerant rice varieties. The variety needs first to be developed by one of the several research institutions within Bangladesh. It then requires the seeds to be distributed to farmers. In addition knowledge regarding the existence of the improved seeds and changes to cultivation practices need to be disseminated. These three interlocking systems (research and development, distribution, knowledge extension services) are all required for the adaptation signature to be effective.
Building improved defenses, irrigation and drainage
Bunds to keep salt water out of fields at high tide and during floods, and drainage channels to allow water used to leach out salt to drain away are all important infrastructure for keeping salinity levels tolerable. Actions to improve infrastructure at the farm level is typically performed by farmers, however this is limited to local action and a more coordinated national approach is probably needed. Costing such local action in monetary terms is very difficult since the monetary value of local, unpaid labour is difficult to quantify. While the research team recognised the importance of local infrastructure they did not attempt to quantify it.
Costing adaptation: Saline tolerant varieties
Saline Tolerant Varieties
As with costing of adaptation in many settings it is very difficult to break down costs between climate change adaptation and development for the institutional actors. The agricultural research and extension institutions are attempting to improve food production and availability given several constraints, of which climate change is one aspect. Even without increasing climate variability into the future, research to improve farming practices and yields would be necessary. Many of the activities they are engaging in do have a positive impact on adaptation, but these activities cannot be entirely attributed as being climate change adaptation actions.
Furthermore the costs of strengthening institutions over the next 20 years are very sensitive to the growth rate assumed for these institutions.
Annual costs estimated for now and for 2030 are shown in the Table below.
Adaptation Costing for Bangladesh
Local (awareness and demonstration in 3 districts)
US$ 2.5 million
District (agriculture marketing, grain storage, insurance, credit linkages)
US$ 7.3 million
National: Rice research and dissemination, variety improvement, biotechnology research, impact assessments, agriculture sector development)
US$ 10.3 million
US$ 32.4 million
National Institutional Arrangements
Bangladesh has a very dense agricultural institutional framework, with as many as 12 departments and institutes falling under the Ministry of Agriculture that are relevant for various aspects of agricultural adaptation. While this is desirable to ensure that all adaptation and food security functions from production to utilization are covered, it may lead to system complexities that slow down implementation, or the absorption of adaptation funds by bureaucratic functions. Because the stakeholders consider the development of saline-tolerant varieties as the main adaptive measure required to address salinity, most of the actions lie with government institutions responsible for these actions. There are, however, other land husbandry and marketing related activities that are also required at the local level, but their costs are very low compared to national costs.
The key issues to consider in planning the adaptation of Bangladesh’s agricultural system that we have considered are:
1.) The capacity building of institutional/ relevant government and non-government authorities to implement activities at all levels efficiently and effectively.
2.) Build on proper coordination among different relevant government agencies and also among agencies (inter and intra) to actually get work done successfully.
3.) Case part of the fund allocation must support research initiatives both by the government and non-governmental organisation for structural and non-structural organisations for infrastructure development of structural organisations.
4.) Monitoring, evaluation and supervision to follow-up and scale up activities in all levels through an independent body, comprising of government and non-government representatives/ experts both at the national and sub-national administrative structure.
5) Farmer’s are using extensive traditional knowledge in regards to adaptation. Advanced scientifically tested techniques should be disseminated in order to gain better results. This must be addressed using awareness raising exercises, namely training programs.
6) The costs of using climate smart varieties are equal to that of traditional varieties. This will allow the user (farmer) to accustom to resilient technology efficiently.
National Study Team
Content produced by: The Bangladesh Centre for Advanced Studies is an independent research, implementation and policy institute for sustainable development. http://www.bcas.net/