Impact of Desertification

 

Economic and social consequences of land degradation are undoubtedly a great concern for the country. One of the main social consequences is, in fact, an economic one, namely reduction of income for farmers. The milder forms of land degradation, for example soil nutrient depletion, can be reversed by changes in management; the resource is renewable and the degradation is reversible. However, in the case of two severe forms of degradation, land productivity in some cases can be restored by reclamation. In case of soil erosion, some of the effects may appear to be reversible, through checking further erosion by soil conservation measures and restoring lost nutrients and organic matter. But where gulling caused loss of land, or severe sheet erosion has removed the soil down to a gravelly residue, degradation is clearly irreversible

 

About 6.0 M ha, or 43% of the total geographical area is affected by various forms and degree of degradation. About one fourth of the total cultivable land is affected by drought in every year with different intensity. The recovery of such land depends upon its resilience, which, however, may be lost completely if the land is not treated in time with care. Frequent droughts, through its short-lived but recurrent stress, can aggravate the adverse impact and, if not checked properly, can interfere with the natural capacity of land to recover and advance the process of desertification.

 

Summary of estimates of the cost of land degradation in Bangladesh

 

Nature of degradation	Physical quantity of lost output In mt/yr	Taka equivalent / yr (million)	Cost(million) US$/yr	Remarks
Water erosion	Cereal production loss  = 1.06 Nutrient loss                = 1.44	6613.84   25576.46	140.72   544.18
Fertility decline	Cereal production loss  = 4.27 Addl. Inputs                = 1.22	26641.48   21668.88	566.84   461.04
Salanization	Total production loss  = 4.42	27577.25	586.75
Acidification	Total production loss  = 0.09	561.51	11.95
Lowering of water table	-	-		Not assessed
Water logging	-	-		Not assessed

 

Source: BARC 1999

Agricultural intensification and the increase in irrigated area have led to a number of environmental problems i.e., loss of bio-diversity through the conversion of forest land into agricultural land; abandonment of many indigenous crop varieties in favour of HYV 's leading to irreversible loss of the country's genetic resources; depletion of soil nutrients and organic matter due to intensive cropping; and deprivation of soil from organic content due to use of crop residue as fuel. Other environmental degradation includes loss of wetland habitats through abstraction and drainage resulting in depletion of aquatic fauna and flora and reduction in water availability to the rural population, increased use of agro-chemicals raising the pollution potentials of surface and ground water.

 

Adverse conditions resulting from desertification process are:
(i) deterioration of the natural resources adversely affecting the socio-economic condition and livelihood support systems;
(ii) reduction of irrigation potential;
(iii) diminishing of the food security base of human beings and livestock;
(iv) scarcity of drinking water extraction and depletion of ground water, interference with spacing of tubewell, including hand tubewell, shallow and deep tubewell;
(v) health and nutrition status of the population, arsenic contamination in ground water, contamination due to disposal of waste and inadequate sanitation;
(vi) reduced availability of biomass for fuel;
(vii) loss of bio-diversity; and
(viii) impoverishment, indebtedness and distress sale of assets of production.

 

Comparison of Economic loss from soil degradion-economic model vs direct productivity estimate