Environmental Problems/issues in Bangladesh

This article was taken from here by CareerGuideBD.

Classification of environmental problems
Current environmental problems/issues in Bangladesh
Water pollution
Air pollution
Deforestation
Soil erosion and degradation
Drought
Depletion of biodiversity
Natural calamities
Severe overpopulation

Water pollution

Water pollution is a natural or induced change in the quality of water which renders it unsuitable or dangerous as regards food, human and animal health, industry, agriculture, or fishing etc.

Surface water pollution
Groundwater contamination
Water shortages because of falling water tables

Surface water pollution

Industrial source: chemical pollutants
Urban source: sewage water, household sewage
Agricultural source: fertilizer, insecticide, pesticide
Cultural source: religious or cultural congregations

Groundwater contamination

What is Arsenic?
Arsenic – a metalloid element – is a natural part of the earth’s crust in some parts of the world and may be found in water that has flowed through arsenic-rich rocks.
Bangladesh is very much dependent on groundwater both for drinking and irrigation purposes. Until the discovery of Arsenic, groundwater was considered safe for drinking. Tubewells have, in the majority, replaced the traditional surface water sources and diarrhoeal disease has reduced significantly. An estimated 97% of drinking water of the rural population in Bangladesh is now supplied by groundwater.

The World Health Organization (WHO) has set a provisional guideline value of 0.01 mg/l [10 parts per billion (ppb)] for total arsenic in drinking water.
The Government of Bangladesh has set a provisional water quality standard of 0.05 mg/l (50 ppb) arsenic for drinking water.

Arsenic poisoning
It can take many years for the effects of drinking arsenic
contaminated water to show and the true extent of the problem is therefore not yet known. Nevertheless, evidence of chronic arsenic toxicity is accumulating and includes melanosis (abnormal black brown pigmentation of skin), hyperkeratosis (thickening) of palm and sole, gangrene and skin cancer.
Malnutrition and hepatitis B, both of which are prevalent in Bangladesh, accentuate the effects of arsenic poisoning.

Arsenic catastrophe: Scale of the problem

Arsenic contamination of groundwater has affected 59 of the 64 districts in Bangladesh where arsenic levels have been found to be above the nationally accepted limit.
It is reported that above 21 million people are currently exposed to arsenic contamination and approximately 70 million people may be at risk.
DPHE, British Geological Survey and Mott MacDonald Ltd. survey (approximately 3500 samples) throughout Bangladesh, but excluding the Chittagong Hill Tracts, revealed that 27% of the shallow tube-wells are contaminated with arsenic above the level of 0.05 mg/l and 46% of the shallow tube-wells tested are contaminated with arsenic above the WHO guideline 0.01 mg/l.

Solutions:

Identification of safe tube wells
Groundwater treatment
Treated surface water
Use of hand-dug wells in reducing aquifers
Rainwater harvesting

Air pollution

According to the Department of Environment (DoE), the density of airborne particulate matter (PM) reaches 463 micrograms per cubic meter (mcm) in Dhaka during December-March period – the highest level in the world. Mexico City and Mumbai follow Dhaka with 383 and 360 mcm respectively. (The Daily Star, November 11, 2009)

City dwellers and road users regularly breathe, contains lead in concentrations reportedly almost ten times higher than the government safety standard set by the Department of Environment. (The Daily Star, April 12, 2008)

About 50 tons of lead are emitted into Dhaka city’s air annually and the emission reaches its highest level in dry season
(November-January), revealed a study conducted by scientists of Bangladesh Atomic Energy Commission (BAEC).

Causes of air pollution:
Smoke from brick kilns
Smoke from vehicles
Dust from roads and construction sites
Toxic fume from industrial sites

Industrialisation and mechanized vehicles are two major sources of air pollution in any country.
The main pollutants from gasoline-powered internal combustion engines are carbon monoxide, hydrocarbons, nitrogen oxides, sulfur dioxide, particulates of lead compound and unburned carbon particles. Emissions from diesel engines are smoke, carbon monoxide, unburned carbon, nitrogen oxides and sulfur dioxide.

Problems:
Air pollution seriously affects the respiratory tract and causes irritation, headache, asthma, high blood pressure, heart ailments and even cancer.

Govt initiatives in curbing air pollution:
Ban on two-stroke engine

Deforestation

Bangladesh: Forest Cover, 2005
Total Land Area (ha) 13,017,000
Total Forest Area (ha) 871,000
Percent Forest Cover 6.69%

Ownership of forest land, 2000
Public 98.2%
Private 1.8%

Deforestation may be done to create farmland, to build hydroelectric plants, to sell the lumber, or through careless or accidental burning.

Total forest cover

Forest 1990 (ha) 882,000
Forest 2000 (ha) 884,000
Forest 2005 (ha) 871,000

Annual Change 1990-2000 (ha | %) (2,000) 0.02%
Annual Change 2000-2005 (ha | %) (2,600) -0.29%
Total Change 1990-2005 (ha | %) (11,000) -1.25%

Effect of deforestation
Soil erosion
Increase in the sediment load of the river, siltation of reservoirs and river bed.
Increase in frequency and dimension of floods and droughts,
Intensity of greenhouse effect
Decrease in the supply of raw materials
Social problems in the form of poverty, crime.

Soil erosion and degradation

Physical removal of topsoil (deterioration of soil surfaces) by various agents, including falling raindrops, water flowing over and through the soil profile, wind velocity.
The greatest damage to the soil comes from water and wind erosion. Various kinds of soil erosion such as landslide, riverbank erosion, and coastal erosion are common in Bangladesh.
Accelerated soil erosion has been encountered in the hilly regions of the country, which occupy about 1.7 million hectares.
In a study at the Ramgati station of the Bangladesh Agricultural Research Institute (BARI), total soil loss of 2.0 to 4.7 ton/ha per year was observed.
Besides soil loss, significant quantities of plant nutrients are also depleted from top layer causing a tremendous soil degradation.

The soils eroded from the hills are deposited somewhere in the downstream. Chittagong Hill Tracts are adversely affected by the deposition of coarse materials brought down by runoff water. Country is losing its forest area at the rate of about 3% annually due to deforestation. The deforested area is also becoming susceptible to severe erosion.
Floodplain areas are prone to riverbank erosion.
Some areas of Bangladesh are also affected by wind erosion,
particularly in the Rajshahi and Dinajpur regions during the dry months of the year.

Soil erosion being irreversible, is generally regarded as the most serious problem of soil degradation.
Soil erosion management is based on the following tenets:
a) highly erodible soils must be protected to prevent accelerated erosion, b) potentially productive soils must be conserved properly to sustain their fertility and
c) eroded soils must be rehabilitated while averting their further degradation.

Drought

A prolonged, continuous period of dry weather along with abnormal insufficient rainfall. It occurs when evaporation and transpiration exceed the amount of precipitation for a reasonable period.
Drought causes the earth to parch and a considerable hydrologic (water) imbalance resulting water shortages, wells to dry, depletion of groundwater and soil moisture, stream flow reduction, crops to wither leading to crop failure and scarcity in fodder for livestock. In Bangladesh drought is defined as the period when moisture content of soil is less than the required amount for satisfactory crop-growth during the normal crop-growing season.
One definite manifestation of the onset of the drought is the ‘top burning’ of the bamboo and betel nut trees, that is, they loose green foliage and the fresh leaves turn brown because of lack of moisture in soil and air.

Droughts are common in the northwestern districts of Bangladesh. Drought has become a recurrent natural phenomenon of northwestern Bangladesh (i.e. Barind Tract) in recent decades.
Barind Tract covers most parts of the greater Dinajpur, Rangpur, Pabna, Rajshahi, Bogra, Joypurhat and Naogaon districts of Rajshahi division.
Rainfall is comparatively less in Barind Tract than the other parts of the country. The average rainfall is about 1,971 mm, which mainly occurs during the monsoon.
The average highest temperature of the Barind region ranges from 35°C to 25°C for the hottest season and 12°C to 15°C for the coolest season.
Generally this particular region of the country is rather hot and considered as a semi-arid region.

Meteorologically drought can be classified into three types: permanent drought – characterised by arid climate;
seasonal drought – caused by irregularities in recognised rainy and dry seasons; and
contingent drought – caused by irregular rainfall.
In Bangladesh, the last two types are more prevalent.

Causes of drought
The hydrological and climatic conditions of Bangladesh are
characterised by too much water in the wet monsoon and too little in the dry months.
The drought environment is further aggravated by the cross boundary anthropogenic interventions. About 58 rivers that flow through Bangladesh actually come through India and Myanmar.
The natural flow of these rivers is interrupted by upstream withdrawal of water for economic and household uses as well as for construction of water management structures by the concerns countries. The effect on these structures obstructs the normal flow of water in rivers such as the Ganges (at Farakka), the Punarbhaba (just beyond Banglabandha) and the Tista. These structures mostly divert dry season flow of the rivers, which create not only a scarcity of surface water in NW and SW Bangladesh, but also tend to affect negatively the recharge of groundwater in these regions. Ultimately it leads to moisture loss in a vast area and contributes to drought condition in these two regions of the country.
* Hydrology -study of earth’s water

Depletion of biodiversity

Biodiversity or biological diversity refers to the differences between living organisms at different level of biological organisation – gene, individual species and ecosystems.
The Convention of Biological Diversity (CBD) defined biodiversity as; ‘the variability among living organisms from all sources including; inter alia, terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part’.
Biodiversity is vital for the production of food and to conserve the ecological foundations needed to sustain people’s livelihood.

http://www.mtnforum.org/oldocs/1159.pdf

Biodiversity of Bangladesh: Overview

Geographically, Bangladesh falls near the Indo-Burma region which is one of the ten global hot-spot areas and supposed to have 7000 endemic plant species. Due to its unique geo-physical location Bangladesh is exceptionally characterized by a rich biological diversity. An estimated 5,700 species of angiosperms (flowering plant: a plant in which the sex organs are within flowers and the seeds are in a fruit) alone, including 68 woody legumes, 130 fiber yielding plants, 500 medicinal plants, 29 orchids, three species of gymnosperms (woody cone-bearing plant) and 1700 pteridophytes (plant without flowers or seeds) have been recorded from Bangladesh. In Bangladesh, some 2260 species of plant reported alone from the hilly regions of Chittagong.

Bangladesh possesses rich faunal diversity. It has approximately 113 species of mammals, more than 628 species of birds (both passerine and non passerine), 126 species of reptiles, 22 species of amphibians, 708 species of marine and freshwater fish, 2493 species of insects, 19 species of mites, 164 species of algae (or seaweed) and 4 species of echinoderms with many others.

Major reasons behind biodiversity
depletion in Bangladesh

High population density, extreme poverty and unemployment
Habitat loss, degradation and fragmentation
Illegal poaching
Environmental pollution and degradation
Invasive alien species
Absence of proper institutional arrangements, frameworks and monitoring Global climate change and sea level rise
Lack of true political commitments and willingness
Lack of people’s awareness

High population density, extreme poverty and unemployment

Bangladesh is one of the world’s densely populated countries with a population of more than 150 million. Majority of the people of the country are still living under poverty line and without any permanent job. Besides, more than 85% of the population of the country are living in rural areas and somehow depends upon various natural resources which often lead over exploitation of plant and animal products for their survival and income. Rural fuel consumption pattern is another important issue related to natural resource depletion in the country. Still now, most of the people in rural areas depend on fuel wood which is strongly concerned with degradation and
unsustainable use of various woody and forested areas.

Habitat loss, degradation and fragmentation
Biodiversity is strongly associated with intact ecosystems and natural landscapes, however transformation of land use patterns, expansion of agricultural lands, change in cropping patterns, introduction of high yielding varieties (HYV), urbanization, expansion of road networks, unplanned embankments and other man-made factors have caused immense damage of habitats in all ecosystems.
The following are some underlying factors related to this issue; o Encroachment
o Shifting cultivation
o Urbanization
o Land use change and agricultural expansions
o Commercial shrimp cultivation in coastal mangrove areas

Illegal poaching
There is a big international market (illegal!) on wild animals (and their part, e.g., teeth, bones, far, ivory etc.) for their aesthetic and medicinal value. Peoples involved with this underworld syndicate sometimes illegally hunting/trafficking wild animals to earn some easy cash. Besides, unregulated logging, illicit felling,
indiscriminate harvest of medicinal plants, Non Timber Forest Products (NTFPs), unplanned fishing, using bag nets, bottom trawling fishing, fishing in the breeding season and other factors are causing depletion of biodiversity.

Environmental pollution and degradation
One of the biggest threats to biodiversity in Bangladesh is pollution of air, soil and water. Water is the greatest victim of contributed by toxic agro-chemicals (i.e., chemical fertilizers, insecticides), industrial effluents that are causing depletion aquatic resources and riparian natural resources.

Invasive Alien Species
A large number of exotic (non-native) plants have been introduced into Bangladesh for agriculture, horticulture, forestry, animal husbandry and fisheries. Also some have become escapes accidentally and having adapted with local conditions proliferated profusely. Local people to different agro-ecological conditions have nurtured some of these and some have become invasive over local flora and fauna (Mukul et. al. 2006). Besides, replacing natural plantation with monoculture of short rotation and fast growing species have threatens the existence of local fauna as they have not adapted with this species.

Absence of proper institutional arrangements, frameworks and monitoring Lack of adequate institutional or administrative frame works and suitable policies, weak implementation of existing policies, lack of integration of sectoral activities are other major threats to biodiversity in Bangladesh. Beside these, week institutional capacities and lack of trained manpower in all disciplines dealing with biodiversity, poor coordination and cross sectoral integration, weak national information system and inadequate knowledge on ecosystem structure and function are vital reason for biodiversity loss in the country. Monitoring is particularly important in understanding the fate of ecosystems, habitats and rare and endangered species.

Global climate change and sea level rise
Bangladesh is supposed to be affected mostly due to global climate change which will ultimately lead to sea level rises in near future. It has been roughly estimated that about one-third of the country’s land will go under water. Already, salinity intrusion and decreasing freshwater flow in the mangroves of Sundarbans cause massive vegetation change in the area. It has been supposed that top dying of Sundri and other mangrove species is also happening due to this change (Khan, 2003). Biodiversity may also be vulnerable due to variation in the length and period of climatic events.

Lack of true political commitments and willingness
Unfortunately, no political parties of the country been not included any forestry and biodiversity issue in their political campaign and these issues have also overlooked or weakly recognized or poorly emphasize when they are in power. In some cases, political persons have been found responsible for illegal forest activities (i.e.,
encroachment) and environmental degradation.

Lack of people’s awareness
Lack of biodiversity-related information and knowledge automatically leads to gaps in awareness. Gaps in awareness have been identified at various levels. To start with, most people do not even know that there are so many species of organisms in Bangladesh. Even the educated do not know that there are laws that ban hunting and trade in wild animals, there are laws that protect certain species and ecosystems and that there are laws that are meant to control environmental pollution. Different categories of Protected Areas exist in the country. However, many including the policymakers are not aware of the different management systems that the Protected Areas are placed under.

Natural calamities

Cyclone and storm surge
Flood
Drought
Abnormal rainfall, hailstorms, and lightning
Nor‘wester and Tornadoes

Overpopulation

Population (July 2005) 144,319,628
Population growth rate (2005) 2.09%
Population density (people/sq km) (2005) 1,077.7
Percent rural (2003) 75.8%
The population is relatively young, with the 0–25 age group comprising 60%, while 3% are 65 or older.

The court directed govt. to take steps to control overpopulation. (The Daily Star, August 13, 2010)
Create independent ministry, allocate fund to control overpopulation Example:
The pass rate in HSC exam and seats in higher educational inst. 25 lakhs students will appear in the primary final examination this year.