Desert environments of Republic of Chad

Abstract

Synopsis: This chapter presents an overview of the current status of desertification in Chad and outlines the measures being taken to arrest and reverse land degradation, revegetate bare land and raise household incomes. The outcomes of several successful projects are summarized. Key Points Like most states of the African Sahel, Chad has suffered from the encroachment of the desert. Traditional herding practices and the need for firewood and wood for construction have exacerbated the problem. Lake Chad was one of the largest fresh bodies of water on the African continent and its disappearance will have a tremendous impact on the population surrounding it. The problem of Lake Chad is increasingly complex because of the international nature of the desertification. Lake Chad is a regional problem East African and North African member states of the African Union and UN must deal with it. A collaborative approach to combating the desertification of Lake Chad is needed to reverse the current trends. Land and terrestrial resources in Africa have unparalleled economic, social and environmental value. Traditionally, African societies are agrarian or pastoral, depending directly on subsistence farming to meet their daily needs. Commercial agriculture holds an equally important position, employing the largest share of the workforce in most countries, and contributing significantly to national economic growth, export earnings and foreign exchange. However, national and household dependency on agricultural output has been a significant factor in limited economic growth over the past three decades. Climatic instability 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 freshwater 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 exacerbated 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.