Soil and Water Conservation for Desertification Control in Iran

Synopsis

An overview of both past and on-going efforts to arrest and reverse land degradation in Iran. Iran has areas vulnerable to desertification due to extensive areas of drylands and increasing population pressure on land and water resources. Over-grazing of rangelands is a particular problem. Initially desertification was combated mainly at the local level and involved dune stabilization measures, especially the use of oil mulch, re-vegetation and windbreaks. Several projects are summarized that illustrate the variety of the problems faced in this country that has a large arid zone.

Key Points

• There is an increasing need for research into desertification development and its causes as this can provide an important basis for desertification control strategies and rational planning of land use in arid and semi-arid areas. Desertification is a very complex process. In addition to natural conditions such as climate, vegetation, soil and so on, it involves many human economic activities, for example, agriculture and animal husbandry. Therefore, to combat desertification, one needs not only to improve natural conditions and raise land productivity, but also to ameliorate the use and management of natural resources in desertified areas.

• In 2004 a national plan to combat desertification was ratified and this placed an emphasis on community participation. Continuing challenges include managing existing desertified areas as well as taking into account potential future problems associated with rapidly depleting groundwater supplies and a predicted reduction in the plant growth period accompanying climate change.

• There is no accurate estimate of soil erosion in different parts of Iran. But 20 years records from 120 gauging stations were examined to evaluate soil erosion and sediment yield in some watersheds in Iran. From 37 sub-basins in Iran, data from 24 of them were used for this study which covered more than 37 million hectares. The results show that watersheds under study have an average annual sediment yield of 750 t/km² and an erosion yield of 2,500 t/km².