Country Profile

COUNTRY PROFILE - BANGLADESH

Physiography

The People’s Republic of Bangladesh lies in the north eastern part of South Asia between latitudes 20° 34' N and 26° 38' N and between longitudes 88° 01' E and 92° 41' E having a gross area of about 147,570 km2 and is bounded on its west, north and north-east by India, on its south-east by Myanmar , and on its south by the Bay of Bengal.

The landmass of Bangladesh is extremely flat built by the delta-building activities of the three major rivers - the Ganges, the Brahmaputra and the Meghna with some upland in the north-east and the south-east. The great plain lies almost at sea level along the southern part of the country and rises gradually towards north. Land elevation in the plain varies from 1 to 90 metres above sea level from south to north. The maximum elevation is 1230 metres above sea level at Keocradang hill in Rangamati hill district. The geo-morphology of the country comprises of a large portion of flood plains (79.1%), some terraces (8.3%) and hilly areas (12.6%)

Climate and Rainfall

Bangladesh enjoys generally a sub-tropical monsoon climate. While there are six seasons in a year only, three of them, Winter, Summer and Monsoon are prominent. Winter, which is quite pleasant, begins in November and ends in February. In Winter there is usually not much fluctuation in temperatures which ranges from minimum of 7.22°-12.77° Celsius to maximum of 23.88°- 31.11° Celsius. The maximum temperature recorded in Summer months is 36.55° Celsius although in some places this may occasionally rise up to 41° Celsius or more. Monsoon starts in June and stays up to October. This period accounts for 80% of the total annual rainfall. The average annual rainfall varies from 1429 to 4338 millimetre. The maximum rainfall is recorded in the coastal areas of Chittagong and northern part of Sylhet district, while the minimum is observed in the western and northern parts of the country.
Cyclonic storms with winds of more than 120 km/hr occur with the advent of the monsoon season. These are particularly severe just before and after the monsoons, in May and October; winds of over 160 km/hr velocity, heavy downpours and tidal surges of over 6 m above the normal level have brought devastation to life and property more than once in the recent past.
Maximum evaporation in Bangladesh occurs during the summer months (March-May), the highest evaporation generally occurs during April. The mean monthly evaporation varies from the minimum of 51 mm in winter to a maximum of 183 mm in summer. The rate of evaporation in the eastern part is generally lower than in the western and northern-western parts. Humidity ranges between 60% in the dry season and 98% during the monsoon.

Population and Size of Holdings

Bangladesh is one of the most densely populated country in the world with an average of about 842 persons/km2 over the country. In January, 1996, the population of Bangladesh was estimated at 124,300,000 inhabitants, of which 78% are rural. The annual demographic growth rate is estimated at 1.75%. The agriculture sector continues to play a very important role in the economy of the country. It accounts for about 32% of the GDP and 68.5% of the national employment.

The average holding size per farm-household in 1996 was 0.7 ha. Nearly 28% of farm households own very little land; less than 0.2 ha and another 51% own up to 1.0 ha.

Land Resources

Of the total land area of 14,757,000 ha. the cultivable area is estimated at 8,774,000 ha, which is about 59% of the total area. In 1996-97, the total cultivated area amounted to 7,860,000 ha. of which 490,000 ha was under permanent crops. Of the total area cultivated annually , about 37% was under single cropping, 50% was under double cropping and the remaining 13% was under triple cropping. In 1996-97, due to double and triple cropping, the total cropped area amounted to about 13.80 million ha, giving an average intensity of 175%. The total forest area covers about 14% of the land area of Bangladesh.

Available data on broad categories of land during 1974 to 1996 shows (Table 1) that in the past 25 years land under “not available for cultivation” has increased from 19% in 1974 to 27% in 1996. It can be safely presumed that most of this land has been used for non- agricultural purposes such as urban development and construction of various infrastructure.

Table 1. Land Use in Bangladesh 1974-1996

Source: Ibrahim Khalil, 1991 and Bangladesh Bureau of Statistics, 1998

Soils

The greater part of Bangladesh lies within the delta of the combined Ganges-Brahmaputra-Meghna River System, and is endowed with fertile soils capable of sustained high yields. Bangladesh can be classified into 7 tracks of soils called red soil tract, Barind tract, Gangetic alluvium, Teesta Silt, Brahmaputra alluvium, Coastal saline and unclassified hilly soils.

Water Resources

Surface Water

Most of Bangladesh is located within the flood plains of the three great rivers: the Ganges, the Brahmaputra and the Meghna, and their tributaries, such as Teesta, Dharla, Dudkumar, Surma and Kushiyara. The three major river systems drain into the Bay of Bengal passing through Bangladesh.

1. The Brahmaputra river enters Bangladesh in the north and flows to the southward for about 270 km to join the Ganges river at Aricha, about 70 km west of Dhaka in central Bangladesh.
2. The Ganges river flows east-south-easterly for about 212 km from the Indian border to its confluence with the Brahmaputra, then under the name Padma it flows for about a further 100 km to its confluence with the Meghna at Chandpur.
3. The Meghna river flows southwest, draining eastern Bangladesh including the hills of Assam, Tripura and Meghalaya to join the Padma at Chandpur. The Meghna then flows southward as lower Meghna for 160 km and discharges into the Bay of Bengal.
   

The combined discharge of the three main rivers is among the highest in the world. Peak discharges are of the order of 98,600 m3/s in the Brahmaputra observed in 1988, 76,000 m3/s in the Ganges in 1987, 19,800 m3/s in the upper Meghna in 1988 and around 160,000 m3/s in the lower Meghna in 1988.

Out of the 230 rivers in the country, 57 are transboundary coming from India (54) and Myanmar (3). About 93% of the catchment area of the river systems is located outside the country. On an average 1,009,000 Mm3 of water cross the borders of Bangladesh annually, 80% of it occurs between June and October. Of the annual total, 50% is contributed by the Brahmaputra at the border, and another 5% by its tributaries, 38% by the Ganges and another 1% by its tributaries, 6% by the Meghna and its tributaries, and the balance of 1% by the rivers of the Southeast.

The estimated global renewable surface water resources are 1,174,000 Mm3 of which the total average annual runoff generated within the country is 165,000 Mm3.

Ground Water

Besides surface water, ground water is the other major source of water in Bangladesh for agricultural, drinking, municipal, and industrial uses. Ground water plays a very vital role during the dry season and drought periods.

Unconsolidated sediments ranging in age from tertiary to recent, mainly underlie Bangladesh. The sediments are generally thick over most of the country. In general, there are two aquifer in the country: the upper aquifer is the main aquifer. In most areas, these two aquifers are probably hydraulically interconnected. The main aquifer in most parts occurs at depths ranging from less than five meters in the northwest to more than 75 meters in the south.

Ground water levels are highest from August through October and lowest in April and May. A sharp rise in water level generally begins in May and continues until July. The range of fluctuation is from three to six meters in most areas. After July, the rate of rise decreases, and in many areas ground water levels remain almost stationary from August to October, indicating rejection of recharge is the aquifer is filled to the capacity. Recharge to ground water occurs primarily through direct infiltration of rainfall. Actual recharge is considerably less than potential recharges.

The estimated total annual renewable ground water resources are about 21,000 Mm3 which are used for dry season irrigation, drinking, municipal and industrial requirements.

Brief History of Irrigation and Drainage

Irrigation

A system of water control and use has existed in the Gangetic delta for centuries. It consisted of broad shallow canals, which carried the top waters of the river floods, rich in fine silt, to the lands. They were so spaced that water could be distributed with reasonable facility to the rice fields, by means of cuts in the banks called ‘Kunwas’, which were closed when the flood season had passed. During the monsoons, much of the land is covered with water. To avoid inundation, villages are located on the higher ground generally made up by earth obtained from the excavation of tanks, which has the double advantage of retaining the monsoon water for use during the dry season.

The system of water control and use was managed and maintained by the Zamindars (landlords) and the tenants, on a more or less forced co-operative basis, known as ‘Pulbandi’. The long-drawn campaign of the Mahrattas and the Afghans, marking the decline of the Moghal Empire, brought about disorganisation and neglect in the proper maintenance of the system. Nonetheless, ‘Pulbandi’ persisted up to 1947 although in a less positive and effective manner. After 1947 reforms in land tenure were initiated and Government assumed the responsibility for maintenance of the works.

No major organized irrigation development was, however, carried out. The farmers have employed irrigation on a very small scale for many years. Water is lifted from wells and streams by primitive methods to irrigate vegetables, chillies, boro rice and betel leaf. More recently, small pumps have been employed for irrigating larger areas of boro rice and sugar cane. Irrigation projects to serve large areas have been unknown until the first half of the present century. Since 1955 a number of irrigation, drainage and flood control projects have been initiated.

To boost agricultural production a programme for development of irrigation by the use of small portable pumps was taken up in the 1960s. These pumps are put to use on purely temporary and seasonal locations along the smaller streams and waterlogged depressions to irrigate small areas upto 40.5 ha.

In Bangladesh, hoping for some major surface water development, the expansion of minor irrigation (small-scale irrigation) has formed a vital component of the Government’s strategy in agriculture. Irrigation through major canals (large scale-irrigation) covered only 4% of the total irrigated area in 1996-97, the remainder was covered by minor irrigation consisting of low lift pumps (LLP’s: power operated centrifugal pumps drawing water from rivers, creeks and ponds), shallow tubewells (STW’s: with a motorised suction mode pumping unit), deep tubewells (DTW’s: with power operated force mode pumping unit), manually operated shallow tubewells for irrigation (MOSTI’s : extracting water from a shallow tubewell) and traditional systems. At the end of the dry season, the water level can fall beyond the suction limit of the centrifugal pump. In these situations, it is possible to draw water by placing the STW in a pit. Lowering of a STW in a pit is called a deep-set shallow tubewell (DSSTW) or a very deep-set shallow tubewell (VDSSTW). When the static water levels fall further (over 10.7 m), submersible or vertical turbine pumps (FMTW’s : force mode tubewells) are needed.

Between 1950 and 1987, public tubewells, regulations of private installations and public monopolies in the supply of pumps, motors and other equipment were a constraint to the development of irrigation. Since 1972, emphasis has been placed on minor irrigation through low lift pumps and mainly by tubewells (Shallow tubewells (STWs), Deep tubewells (DTWs) and Force mode tubewells (FMTWs)).

From 1979 to 1984, there was a liberalised expansion of minor irrigation with STWs in the private sector. In 1981-82, about 0.20 million ha of land was under irrigation with 43,000 operating STW’s.

Currently, the potential for irrigation is estimated at 7,550,000 ha, of which about 3,690,000 ha had been brought under irrigation by 1996-97. Irrigation through major canals covers about 4% of the total area, the remainder being classified under minor irrigation consisting of surface water (low lift pumps and traditional systems) and groundwater (shallow tubewells and deep tubewells).
At present, irrigation is practiced for boro rice (71%) and wheat (9%), which occupy together 80% of the irrigated land. Irrigation is mainly used in the dry season, although supplementary irrigation could appreciably increase transplanted aman rice production. The total harvested irrigated area is estimated at 3,690,000 ha, which does not account for wet season crops on area equipped with full or partial control irrigation. The national average irrigated paddy yield in 1996-97 for HYV boro was moderately high at 4.0 t/ha. In 1996-97, the total HYV boro rice production amounted to 7.10 million tones, which represents about 38% of the total grain production.

Keeping in view the target of raising the cereal production level to 25 million tons by the year 2002 the fifth five-year plan seeks an overall accelerated growth in agricultural production and productivity. Agricultural Development is still synonymous with economic development of Bangladesh.

Towards a Water Vision

In Bangladesh, the strategy of water resources development has so far pivoted around flood control and irrigation expansion to promote food grain production. Not denying the importance of food production and food security, it is now widely recognized that conflicts among, alternative and competitive uses of water are becoming sharper as population and demand for limited supplies of water are increasing. It is, therefore, necessary to formulate a long-term vision for integrated water resource management (IVA” to address the demands of all water-using sectors and maintain a sustainable environment. Hence, the water vision should reflect, in a holistic manner, a clear perspective of the management of the water ecosystem in the country by taking into account seasonal variations in availability, alternative uses and demands, mechanisms of water supply and demand management strategies, and the guidelines of the National Water Policy. A National Water Management Plan (NWNV) is underway in the light of the policy.
It is assumed that, by 2025, most of the actions/schemes under the NWW would have been implemented or is in the process of implementation. Based on this premise and the need to balance population growth, water demand for food, rural development, the strategic components of a long-term vision are briefly presented below.

Flood Control and Drainage

Because of its low-lying topography, at least 20% of the area of the country is flooded in a normal year. Flood control and drainage is used to reduce the depth of flooding or eliminate, through “controlled flooding”, untimely floods so as to provide greater security for the crop production.

In 1964, a master plan for water resource development was developed which envisaged the development of 58 flood protection and drainage projects covering about 5.8 million ha of land. Three types of polders were envisaged: polders with gravity drainage, tidal sluice drainage and pump drainage.

Flood control and drainage projects have accounted for about half of the total funds spent on water development projects since 1960 they include :

• Major projects such as the Coastal Embankment Project (949,000 ha), the Brahmaputra Right Flood Embankment (226,000 ha), the Pabna Phase 1 Project (197,000 ha), the Ganges-Kobadak Project (141,600 ha), and the Chalan Beel Project (125,000 ha).
• Medium-scale project such as the Satla-bagda, Chenchuri Beel and Barnai-Salimpur-Kulabasukhali Project implemented under the drainage and flood Control Projects (DFC 1 to DFC IV). These projects typically cover areas of 10,000 to 30,000 ha and involve flood control and drainage with limited irrigation development.
• Small-scale projects such as those implemented under the Early Implementation Project, the Small-scale Irrigation Project and Small-Scale Drainage and Flood Control Project.

In 1993, the total area of wetlands was 3,140,000 ha of which 1,545,000 ha were cultivated and 1,383,000 ha were drained through surface drains. In addition, the irrigated areas equipped for drainage represent about 114,400 ha. The flood-protected area in 1990 was estimated at 4,200,000 ha.

Integrated flood mitigation

Since flood is a recurrent phenomenon in Bangladesh and with two-thirds of the country being ulnerable to flooding, a balanced and rational approach to flood management is essential. The approach should consist of a combination of structural and non-structural methods to mitigate flood damages and at the same time, retain the beneficial effects of inundation. However, flood mitigation measures must not be considered in isolation of other components of water resource development. These should be part of an integrated water management plan, along with food production, environment, fisheries, drainage, navigation and household supply.
Flood mitigation measures should also be addressed in the regional context. Bangladesh, being the- lowest riparian in the Ganges, the Brahmaputra and the Meghna systems, face the fury of floods - although all other countries in the region also suffer from flooding of different levels of severity. Hence, there is a need for active cooperation amongst the countries of the GBM region for flood management. A comprehensive scheme of collection, transmission and exchange of real time relevant data among the GBM countries will promote efficiency in flood forecasting and disaster preparedness in Bangladesh.

Bangladesh and ICID

Bangladesh joined ICID in the year 1973 and has played an active role in the activities of the Commission. Late Mr. Amjad H. Khan of Bangladesh National Committee was past Vice President (1984-87) of ICID. Bangladesh is actively represented by Mr. Tauhidul Anwar Khan in the Asian Regional Working Group (ASRWG). Presently, Mrs. Quamrun Nahar Khanam is the Chairperson of the Bangladesh National Committee. Bangladesh National Committee hosted the International Seminar on Evolution of a Scientific System of Flood Forecasting and Warnings in the Ganges, Brahmaputra and Meghna Rivers from 5-6 December 1997.