مصايد الأسماك الداخلية

Environmental impact assessment of irrigation and drainage projects

Linkages to water management
30/05/1995

The importance of environmental protection and conservation measures has been increasingly recognized during the past two decades. It is now generally accepted that economic development strategies must be compatible with environmental goals. This requires the incorporation of environmental dimensions into the process of development. It is important to make choices and decisions that will eventually promote sound development by understanding the environment functions. The United Nations Conference on Environment and Development (UNCED) in its Agenda 21, Chapter 18: Protection of the Quality and Supply of Freshwater, underscored the importance of environmental protection and conservation of the natural resource base in the context of water resources development for agriculture and rural development.

Much of the land currently under agriculture is deteriorating due to inappropriate planning, implementation and management. Natural resources, particularly soil and water, are being seriously affected. Soil erosion, desertification, salinization and waterlogging reduce productivity and jeopardize long-term sustainability. Agricultural expansion programmes have often encompassed marginal land in many parts of the world. Wise management of the environment requires an ability to forecast, monitor, measure and analyse environmental trends and assess the capabilities of land and water at different levels, ranging from a small irrigated plot to a catchment. Adoption of environmental impact assessments (EIAs) will enable countries to plan water and land use in an integrated manner, avoiding irreversible environmental damage. Contrary to common perceptions, this would lead to higher economic benefits and sustainable resource use.

Irrigation and drainage projects invariably result in many far-reaching ecological changes. Some of these benefit human population, while others threaten the long-term productivity of the irrigation and drainage projects themselves as well as the natural resource base. The undesirable changes are not solely restricted to increasing pollution or loss of habitat for native plants and animals; they cover the entire range of environmental components, such as soil, water, air, energy, and the socioeconomic system.

A increasing number of developing countries are accepting the principle of environmental screening of development projects at the planning stage and hence are looking for guidelines to environmental impact assessments. Many multi- and bilateral agencies stipulate environmental impact assessments of proposed developments as a condition for lending, technical assistance and development support. FAO has, for quite some time now, been emphasizing the environmental impacts of irrigation and drainage projects, and provided technical assistance to a few countries in evaluating environmental impacts. The challenge now is to provide the appropriate tools to those who wish to undertake environmental impact assessment in irrigation and drainage projects; a guide to a systematic approach to developing a basic understanding of the environmental problems and a methodology to assess the scope and magnitude of environmental damage that may be caused by irrigation and drainage.