Aspects of Environmental Degradation in
M. Munir uz Zaman
M. Munir uz Zaman
2. The total amount of water flow is vast, next only to the Amazon system. However there are significant variations in the availability of water between wet and dry seasons.
3. The country has been largely created by the vast quantity of sediments carried by the river systems. The sediment deposits are thick, and has made the soil fertile suitable for a high level of agricultural activities.
4. The population density is very high, in fact the highest in the world.
5. Although the land area is only 55000 sq miles, it has significant biodiversity
The above features, true as they are, may create an impression that the country is gifted with plenty of life supporting water, good soil for farming activities and clean air as considerable bio-diversity would suggest. Unfortunately in recent decades, the state of environment has been showing signs of serious stress as revealed through a number of field observations and studies.*
The state of environment degradation may be approached by examining four key areas:
a) Water pollution and scarcity
b) Land degradation
c) Air pollution
d) Extent of bio-diversity
A state of environmental degradation
is driven basically by, (a) population growth, and (b) application of
unfriendly technology. In most cases, if not all, the presence of both has been
at work in
Water Scarcity and Pollution
In the past there had been a secular decline in surface water availability in the north and south western part of Bangladesh sometimes called ‘moribund delta’, as tributaries of the Ganges in the north and distributaries in the south began to silted up. The process was
by the upstream of diversion of water from the river system for consumptive and
non consumptive uses. The reduced availability of surface water in the region
adversely affected the normal recharge of the ground water table in a number of
areas. A smaller surface water run off also impacts on
salinity level in the coastal areas. For example: in
The surface water quality is
affected by untreated industrial effluents, Municipal waste water and run off
from the surface of the agricultural lands treated with pesticides and chemical
fertilizers. Pollution problems in the rivers close to the industrial areas are
exceedingly high. For example: The dissolved oxygen (DO) level in the Buriganga has been found to be very low, and hence toxic.
The Sitalakhya, Turag and Balu are also highly polluted. The water quality in
The levels of
arsenic contents in the ground water is of major concern in
Land degradation varies according to regions. Land degradation in the flood plains is chiefly attributable to improper use of fertilizer and pesticides. In the coastal areas it is partly due to the nature of shrimp culture which requires letting in saline water into empoldered shrimp beds. Erosion of topsoils in the hilly districts has increased. It is estimated that 17% of the soil in the hilly districts has deteriorated between 1964 and 1985. Excessive irrigation of agricultural lands may also contribute to soil degradation. For example: it was observed in Chandpur irrigation project area that deficiency of Zinc content in the soil had occurred through leaching. The deficiency was corrected simply by injecting Zinc into the soil of the affected areas. Soil resources development institute (SRDI) has found that Nitrogen deficiency is a common phenomenon in the country. In Sylhet areas Phosphorus deficiency in the soil has been noticed.
In order to combat the adverse effects the government started a program of integrated pest management (IPM) from 1981. The program has made immense contribution to containing the bade of the use of pesticides for crop production as a whole. It has also helped reduce the application of pesticides. Another concept that is emerging is integrated plan nutrient system (IPNS) involving application of external nutrients based on soil capacity and crop need.
The air quality of the country is
generally good. However in urban areas particularly in
a) Banning the use of two stroke engine vehicles. Such engines emit unburned hydro- carbons and carbon monoxide 30-100 times more than four stroke engines. It is expected that two stroke engines will be will be phased out through out the country over a short period of time.
b) Introduction and promotion of increased use of compressed natural gas (CNG) in vehicles in place of gasoline.
c) Leaded gasoline is another major air pollutant. In 1999 the Government decided that only unleaded patrol would be supplied.
A few more steps in protecting the city air is possible. The Department of Environment claims that pollution from vehicular emissions can be reduced by about two thirds by the use of low smoke lubricants and inspection and maintenance of vehicles. However industrial emission continues to be serious problem. Though the solution is more complex and probably more costly it has to be addressed seriously.
Bio diversity in
The Sunderbans, one of the largest mangrove forests in the world, supports 300 species of plants, 400 species of fish and over 200 species of birds. It is also the feeding area of migratory birds during winter.
However like other sectors of
Overfishing under conditions of
population pressures has depleted the fish resources. Hilsa
fish for which
It is evident from the brief
discussions in the preceding paragraphs that the ecology of
A foremost task will be to build a measure of public awareness of the danger to the quality of human life. The work undertaken by the civil society groups and the government needs to be pursued and further expanded. The subject of environmental concern could part of the educational policy and can be integrated in the teaching programs at school level.
Although a good number of laws for containing pollution have been enacted, their implementation has been uneven. For example: the laws regarding aspects of industrial pollutions have not always been rigorously implemented. Even of when a sound decision has been taken, its implementation gets delayed or is bogged down on various grounds. Relocation of the tanneries at Hazaribag is a case in point. Another example is the unabated catch of fish fries despite the presence of very clear legal provision for handling the offense.
of Environment Report, 2001, Department of Environment/UNEP Bangladesh State
Environment 2001, Unnyan Shamannay, University Press. Bangladesh
Environment and Poverty, ed. Atiq Rahman, The University Press.
Report on leather industry, report by MA, Redwan Billah; ed Philip Gain et al, published by SHED.
** State of
*** Peoples’ Report on Bangladesh Environment v1 by Atiur Rahman, et.al, University Press (ch4).