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Newsletter and Technical Publications Operation and Maintenance Construction of terraces depends to a large degree on cooperation between residents, thereby reducing labor costs for their construction, as well as their maintenance. This cooperation is called Al-Awanah in Yemen. After their construction, the terraces need continuous care and maintenance. Inadequate maintenance over a long period of time can result in partial destruction or total loss of the terraces. The maintenance process includes monitoring the conditions of the rock walls, their stacking and interlocking, and ensuring the voids between the walls allow excess water to flow to the lower platforms. If these voids are clogged with mud, sediment or weeds, the platform area will be flooded. This will result in unnecessarily increasing the quantity plants in the flooded platforms, while depriving the lower platforms of an adequate water supply. It is emphasized that construction of these terraces is both for economic purposes (i.e., securing new agricultural lands), as well as reducing soil erosion. If maintenance of the terrace walls is ignored, the runoff water can cause partial or complete failure of the platforms, enhancing soil erosion and potentially causing major catastrophes, such as that which occurred in Yemen. Level of Involvement Although terraces are economically feasible, they have attracted more interest in the past than at the present time. The primary reason is the migration of rural residents who have discarded agriculture as a living, or who tend to cultivate in the extended plains in order to secure higher economic returns. Past interest in this technology has focused on the individual. However, some governments in the region are implementing land reclamation projects on the hills as a means of trying to increase the economic return for farmers and to attract them back to their land. Among the governments adopting this approach are Syria, Yemen, Saudi Arabia, Oman and Jordan. Nevertheless, the necessary maintenance activities remain the farmer’s responsibility. There is no government interest in this technology in Palestine, due largely to the Israeli occupational authorities, who have not shown any interest in it. As a result, interest in the technology is essentially pursued only by Palestinian farmers in the villages under their authority. Outside of the village limits, however, no interest is being shown in the existing old terraces. As a result, they are rapidly deteriorating. In order to facilitate the greater acceptance of this technology, it is clear that the relevant authorities must carry out campaigns for the farmers that focus on its benefits to the region, the procedures for its construction, the maintenance requirements,and the expected economic return for employing it. Costs The costs of terraces are generally considered high. However, they appear to be economically feasible over the long term, primarily because of their direct financial return to the farmers or to their indirect returns. The latter are achieved through the utilization of runoff water to increase the soil moisture content, rather than losing the water to evaporation, and also to reduce soil erosion due to surface runoff. Where the slope is suitable, terraces are mechanically executed with bulldozers, in order to reduce construction costs. In the case of very steep slopes, terraces are manually excavated, and the construction costs become high. Terraces require technical supervision of their construction, as well as continuous maintenance. Their costs, therefore, are considered high. In the case of cooperative work, however, the costs of terrace construction becomes negligible. This is due primarily to the farmers themselves leveling the land with their traditional tools, collecting rocks from the site and building the platforms walls, as is practiced in Palestine. Effectiveness of Technology Terraces are considered the most efficient technology for rainwater harvesting and soil conservation on slopes. They also are one of the best methods for land reclamation, in which the goal is to transform low-yielding agricultural land with slopes into high-yielding land. Terraces also increase the moisture content of the soil, allowing for the growth of high-value crops (grains, legumes, fruit trees). Areas with terraces generally are erosion-free, green-covered land used for cultivation and farming. Suitability As previously noted, this technology is most useful on land with slopes, especially those with inclinations ranging between 10-35%, and an annual rainfall ranging between 200-500 mm. It is worth mentioning that the mountainous nature of Palestinian lands makes this technology very suitable for Palestinian conditions. Advantages The advantages of this technology are as follows:
Disadvantages The disadvantages of this technology are as follows:
Cultural Acceptance This technology has been used in different areas of the countries of the West Asia region for a lenghty period of time. Thus, it is a well-known technology, representing a heritage value for the local populations. In ensuring sufficient quantities of irrigation water, construction of terraces creates a source of income for local residents, and increases the financial return through increased production. This also encourages farmers to remain in the regions. To enhance the use of this technology, therefore, will not necessarily require great efforts to convince the agricultural populace of its benefits. Nevertheless, some efforts are still needed to increase the awareness of this technology and to convey knowledge to the residents on the best methods for constructing the terraces (in regard to design and maintenance), thereby guaranteeing their sustainability. It is likely that some financial support to farmers and residents during the terrace construction phase also will be required. Further Development of the Technology Further development of this technology would include the following:
Information Sources Contacts Abdel-Karim Mohsen Al-Fasil Abdel-Naby Fardous Mohammed El-Kholy Marawan Haddad Ma’amoun Malakany References ACSAD and UNESCO. 1985. Main regional project for the optimum use and maintenance of water resources in rural areas in the Arab countries, concentrating on conventional water systems. Technical report, ACSAD, Damascus, Syria. 370 p. ACSAD. 1983. Analysis and development of the Arab water technologies. Country reports, ACSAD, Damascus, Syria. Abdel-Karim Al-Fasil and Abbad Mohamed Al-a’nsy. 1999. Conventional technologies for water use in Yemen, Sanaa. Technical report. FAO. 1994. Water harvesting for improved agricultural production. Proceedings, FAO Expert Consultation, 21-25 November, 1993, Cairo, Egypt. Haddad, M. 1994. A survey of rainwater harvesting in Palestine. Study report, Palestine Consultancy Group and University of Ottawa. ICARDA. 1987. Supplemental irrigation in the Near East and North Africa. Proceedings, Workshop on Regional Cconsultation on Supplemental Irrigation, ICARDA and FAO, 7-9 December, 1987, Rabat, Morocco, Perried and Salikini (eds.), Kluwer Academic Publishers. 911 p.
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