Desert Environments of Republic of Chad - Combating Desertification in Asia, Africa and the Middle East - page 161

has caused significant and frequent variability in production, and narrow crop
diversity, and national and international market failures, have facilitated recurrent
economic losses.

• Desertification, land degradation and drought have negative impact on the

availability, quantity and quality of water resources that result in water scarcity.
As desertification takes its toll, water crises are expected to continue raising
ethnic and political tensions in drylands, contributing to conflicts where water
resources straddle or delineate country borders. Water scarcity is the long-
term imbalance between available water resources and demands. Increasing
occurrences of water scarcity, whether natural or human-induced, serve to trigger
and exacerbate the effects of desertification through direct long-term impacts on
land and soil quality, soil structure, organic matter content and ultimately on soil
moisture levels.

• The direct physical effects of land degradation include the drying up of freshwa-

ter resources, an increased frequency of drought and sand and dust storms, and
a greater occurrence of flooding due to inadequate drainage or poor irrigation
practices. Should this trend continue, it would bring about a sharp decline
in soil nutrients, accelerating the loss of vegetation cover. This leads in turn
to further land and water loss from pollution of surface and groundwater,
siltation, salinization, and alkalization of soils. Poor and unsustainable land
management techniques also worsen the situation. Over cultivation, overgrazing
and deforestation put great strain on water resources by reducing fertile topsoil
and vegetation cover, and lead to greater dependence on irrigated cropping.
Observed effects include reduced flow in rivers that feed large lakes such as Lake
Chad, leading to the alarmingly fast retreat of the shorelines of these natural
reservoirs in Chad. With climate change, the situation is likely to get worse - less
water and creeping desertification in the semi-arid terrain.

• Declining productivity and soil structure in the Sahelian zones of Chad is exac-

erbated by unpredictable rainfall and drought, resulting in extreme degradation
and desertification. Chad is currently experiencing the greatest vulnerability to
desertification, with 58 % of the area already classified as desert, and 30 %
classified as highly or extremely vulnerable.

• Rapid population growth and policy pressures to increase production have forced

the cultivation of greater and greater areas of land in all sub-regions, and the
extension of cultivation and grazing to marginal areas. Combined with limited
application of organic or inorganic fertilizers, reductions in fallow periods,
restrictions on crop diversity, inappropriate irrigation, and an increasing use
of herbicides and pesticides, this has resulted in the physical, chemical and
biological degradation of vegetation and soil. Soil erosion and desertification
rates are increasing as a result, and declines in productivity have been noted.

Keywords Dust storms • Wildlife • Biodiversity • Shelter belt • Oasis •

Camels • Poverty • Ostriches • Lake Chad • Palms • Great Green Wall •

Poverty • Armed conflict • Food insecurity • Ethnic tensions