In recent times, the loss of vegetation in the area
has vastly degraded their once fertile land, and water has become a rare
commodity. Since 1999, the failure of the monsoon has adversely affected the
soil and the land has become barren. In order to regenerate it, ravines and
ridges were treated by constructing gully plugs and digging out contour
trenches. Earth check dams with spillways on either side were built to allow
the water overflow to run off without damaging the dams. Ponds were also constructed to hold larger
volumes of water.
As farmers witnessed the effects of lack of water
and soil erosion and its detrimental impact on agricultural production and
yields, the concept of watershed management gained credence amongst them. Many
are convinced that the local environment can be regenerated through a
well-managed watershed programme.
Many now understand the fact that as the groundwater
increases, normal farming patterns and agricultural output levels can be
maintained despite changing weather conditions. The community has now learned
to conserve their water and soil. Not a single drop of water runs off in their
village. Caritas India has run public information campaigns trying to persuade
local communities to take similar measures to stop desertification. Even though
India’s land area is only 2.4 percent of the world’s total land area, it
supports 16.67 percent of the world’s population and 18 percent of its
livestock. These pressures alone play a major role in promoting
desertification.
As the human and animal population increases, these
stresses will become greater and the demand on natural resources will increase
leading to permanent loss of vegetation and plant species. This may also lead
to the conversion of large areas into wastelands and to the frequent occurrence
of natural disasters. Half the land in India is now affected by desertification
and this impairs the ability of land to support life. It is particularly
devastating because of its self-reinforcing nature.
The causes of desertification are extensive
cultivation of one crop, use of chemical fertilisers and pesticides, shifting
cultivation without adequate period of recovery, industrial and mining
activities, overgrazing, logging and illegal felling, forest fires and
unsustainable water management. Desertification is a global phenomenon of land
degradation, which reduces the natural potential of the ecosystems and has a
direct impact on people in terms of vulnerability to food shortages and natural
disasters, depletion of natural resources and deterioration of the environment.
4
important Causes of Desertification
1.
Water Erosion
Soil erosion through fluvial processes affect large
areas in the Saurashtra and Kutch uplands, and along the eastern margin of the
Thar Desert where the average annual rainfall varies from 350 to 500 mm, but
has very few occurrence to the west of 250 mm isohyets in the Thar.
The manifestations can be deciphered the pattern of sheet,
rill and gully erosion features. Increased ploughing and destruction of
vegetation cover for fuelwood, overgrazing and other destructive uses, must
have accelerated the erosion in recent decades, but in the absence of specific
data, it is difficult to suggest how much of the gulling activity is due to
human activities alone and how much due to the natural processes. In Kutch
region, a part of the problem is related to a slow natural uplift of the
terrain over the centuries, which leads to a change in base level and increased
erosion.
2.
Wind Erosion/Deposition
The most vulnerable landforms to wind
erosion/deposition are the sand dunes and other sandy landforms in the Thar. A
closer look, however, indicates that the sandy landforms in the east are more
stable than the similar landforms in the west. Rainfall gradient and wind
strength are both responsible for the spatial variability in sand reactivation
pattern.
The introduction of the tractor for deep ploughing,
instead of the traditional animal-driven wooden plough, has increased the sand
load manifold for the Aeolian processes in large parts of the desert, and
accelerated the mobility of sand.
Increased destruction of the natural land cover in
grazing lands for fuel and fodder and enlarging the frontiers of cultivation to
less suitable sandy areas are also the responsible factors. In the foothills of
the Aravali hill ranges along the wetter eastern part of the desert, such
activities are also leading to accelerated water erosion, as manifested through
the formation of rills and gullies.
The farmers are aware of headword progress of the
gullies in the east, but do not believe that their agricultural activities hasten
the process, unless tractors are used to loosen the soil. Many of them believe
that the agricultural crop residues which they leave in the field are good sand
binders and whatever land is being lost through gully erosion is a slow natural
phenomenon. In other parts of the desert, farmers agree that deep ploughing
with tractors, cultivation along dune slopes, or non-practising of long fallow
systems and other traditional farming systems lead to accelerated sand movement
and land degradation, but they have very few choices, as population pressure
and economic consideration override environment consideration.
3.
Mining
In western Rajasthan, about twenty major minerals
and nine minor minerals are being mined. More than 90 per cent of the mine
owners have open cast mining. The rest are underground mines. The area occupied
by the mines is increasing and by 2000 AD 0.05 per cent of Jaisalmer district
and 1.15 per cent of Jhunjhunu district are reportedly under mining activities.
The surface mining activity causes immediate
degradation of land. The mining sites are abandoned after the excavation work
is over, without adopting any reclamation measure. Mining on agricultural land,
either surface or underground, reduces the productivity of land by way of excavation,
disposal of debris and tailing. Mineral processing like grinding of limestone
for cement industry, calcite and soapstone for ceramic industry, have
three-fold adverse effects.
The fine dust, generated and released in the
atmosphere, leads to surface scaling of the adjacent land after it settles
down, consequently the infiltration rate is reduced and the run-off increases.
Mining activity restricts the sub-surface movement
of water. With the removal of vegetation, the rate of evapotranspiration is reduced
and as a result, there is a change in the hydrological balance in the area.
Due to this change, the perched water table rises
and causes salinity. When the mining debris of minerals like ball clay, china
clay, Fuller's earth, bentonite and gypsum are dumped on the sandy plain, a
semi-impermeable surface layer is developed. These areas get flooded during the
monsoon and gradually develop salinity. Sodium salt mining activity increases
the surface salt concentration, causing total loss of vegetation.
4.
Vegetation Degradation
One of the first casualties of desertification is
natural vegetation. Degradation of natural vegetation is also one of its major
causes. With increasing pressure on land vegetation, degradation is increasing
at an alarming rate.
The common grazing lands around the villages are now
some of the very severely degraded sites, as these are highly exploited and
most neglected. Many good grazing lands have also been encroached upon for
agriculture.
Programmes
Controlling Desertification
India has always maintained that desertification is
a function of the interplay of a number of causative factors and thus only a
multi-sectoral approach alone will be able to arrest and reverse the process of
desertification. Some major schemes/ programmes that have contributed to
desertification control are Drought
Prone Areas Programme (DPAP), 1973-74; Watershed Development Project in
Shifting Cultivation Areas (WDPSCA), 1974-75; Desert Development Programme
(DDP), 1977-78; Reclamation & Development of Alkali Soil (RAS), 1985-86;
Watershed Development Fund (WDF),
Integrated Wasteland Development Programme (IWDP), 1989; National
Watershed Development Project for Rain fed Areas (NWDPRA) – 1990-91 and Soil
Conservation in the Catchment of River Valley Projects (RVP) 1992. National
Afforestation Programme (NAP) 2002-03 is also one of the major programmes in
which Association of Scheduled Tribes
and Rural Poor in Regeneration of Degraded Forests (ASTRP), launched in 1992-93
and Integrated Afforestation and
Eco-Development Projects Scheme (LAEPS) 1989-90 were merged into the National Afforestation Programme.
The year mentioned against the name of the schemes
above designates the year of inception. The three schemes of Desert Development
Programme, Drought Prone Area Programme and Integrated Wasteland Development
Programme have been consolidated into a single programme of Integrated
Watershed Management Programme (IWMP) with effect from 01.04.2008. Recent
initiatives include sustainable Land and Ecosystem Management (SLEM
Programmatic Approach) 2007; Common Guidelines for Watershed Development
Programme- 2008; Integrated Watershed Management Programme (IWMP) and
Guidelines for Convergence between NREGA and NAP 2009.
The basic object of the programme is to minimise the
adverse effect of drought and control desertification through rejuvenation of
natural resource base of the identified desert areas, achieve ecological
balance and overall economic development in the programme areas. The programme
has covered in 235 blocks of 40 districts in 7 States. The corresponding
physical area under the programme is about 4.57 lakh sq. kms.
कोई टिप्पणी नहीं:
एक टिप्पणी भेजें